MAX20069BGTLAV_技术文档

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2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

General Description

Benefits and Features

The MAX20069B is a highly integrated TFT power supply

and LED backlight driver IC for automotive TFT-LCD ap-

plications. The IC integrates one buck-boost converter,

one boost converter, two gate-driver supplies, and a

boost/SEPIC converter that can power one to four strings

of LEDs in the display backlight.

● 4-Output TFT-LCD Bias Power

• 2.8V to 5.5V Input for the TFT-LCD Section

• Integrated 440kHz or 2.2MHz Boost and Buck-

Boost Converters

• Positive and Negative 3mA Gate Voltage

Regulators with Adjustable Output Voltage

• Flexible Resistor-Programmable Sequencing

through the SEQ Pin

The source-driver power supplies consist of a synchro-

nous boost converter and an inverting buck-boost convert-

er that can generate voltages up to +15V and down to

-7V. The positive source driver can deliver up to 120mA,

while the negative source driver is capable of 100mA. The

• Undervoltage Detection on All Outputs

• Low-Quiescent-Current Standby Mode

● 4-Channel LED Backlight Driver

• Up to 150mA Current per Channel

• 4.5V to 42V Input Voltage Range

• Integrated Boost/SEPIC Controller (440kHz or

2.2MHz)

positive source-driver supply regulation voltage (V

) is

POS

set by connecting an external resistor-divider on FBP or

2

through I C. The negative source-driver supply voltage

(V

) is always tightly regulated to -V

(down to a

NEG

POS

minimum of -7V). The source-driver supplies operate from

an input voltage between 2.8V and 5.5V.

• Dimming Ratio 10,000:1 at 200Hz

• Adaptive Voltage Optimization to Reduce Power

Dissipation in the LED Current Sinks

• Open-String, Shorted-LED, and Short-to-GND

Diagnostics

The gate-driver power supplies consist of regulated

charge pumps that generate up to +28V and -21.5V and

can deliver up to 3mA each.

● Low EMI

The IC features a quad-string LED driver that operates

• Phase-Shift Dimming of LED Strings

• Spread Spectrum on LED Driver and TFT

• Selectable Switching Frequency with Fine-Tuning

from a separate input voltage (V

) and can power up

BATT

to four strings of LEDs with 150mA (max) of current per

string. The IC features logic-controlled pulse-width-modu-

lation (PWM) dimming, with minimum pulse widths as low

as 500ns with the option of phase shifting the LED strings

with respect to each other. When phase shifting is en-

abled, each string is turned on at a different time, reducing

the input and output ripple as well as audible noise. With

phase shifting disabled, the current sinks turn on simulta-

neously and parallel connection of current sinks is possi-

ble.

2

via I C

2

● I C Interface for Control and Diagnostics

2

• Fault Indication through the FLTB pin and I C

● Overload and Thermal Protection

● -40°C to +105°C Ambient Temperature Operation

● 40-Pin (6mm x 6mm) TQFN Package with Exposed

Pad

The startup and shutdown sequences for all power do-

mains are controlled using one of the seven preset modes,

which are selectable through a resistor on the SEQ pin or

Ordering Information appears at end of datasheet.

2

through the I C interface.

The MAX20069B is available in a 40-pin (6mm x 6mm)

TQFN package with an exposed pad, and operates over

the -40°C to +105°C ambient temperature range.

Applications

● Automotive Dashboards

● Automotive Central Information Displays

● Automotive Head Up Displays

● Automotive Navigation Systems

19-100899; Rev 0; 9/20

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Simplified Block Diagram

COMP

OVP

ISET

VCC

1 of 4

V

UP/DOWN

COUNTER

+

THH

PWM

COMP

g_M

DRIVE

LOGIC

NDRV

OUT_

DAC

V

THL

CURRENT

REF.

FAULT

DETECTION

SLOPE

COMP

420mV

CS

5V

BATT

REGULATOR

+

UVLO + BG

TEMP

WARNING,

SHUTDOWN

PHASE-

SHIFT

LOGIC

VCC

LGND1,2

DIM

IN

MAX20069B

PGVDD

DP

BST

400kHz

POSITIVE

CHARGE PUMP

TFT BOOST

CONTROL

440kHz/2.2MHz

LXP

TEMP

WARNING,

SHUTDOWN

PGND

FBP

FBPG

1.25V

DGVDD

HVINP

DGVEE

POSITIVE

SOFT-START

AND

POS

NEG

400kHz

NEGATIVE

CHARGE PUMP

DN

DISCHARGE

ENABLE, CONTROL

AND FAULT LOGIC

NEGATIVE

SOFT-START

AND

FBNG

SEQ

DISCHARGE

DGND

EN

INVERTING

REGULATOR

440kHz/2.2MHz

FLTB

INN

I²C

REFERENCE

1.25V

LXN

REF

GND

EP

ADD

SCL SDA

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Maxim Integrated | 2

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

TABLE OF CONTENTS

General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Benefits and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Simplified Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

40-Pin TQFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Typical Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

MAX20069B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Functional Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Detailed Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Detailed Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

TFT Power Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Source-Driver Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Gate-Driver Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Fault Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Output Sequencing Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 1: TFT Sequence with RSEQ=10k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Description of the LED Driver Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Current-Mode DC-DC Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

8-Bit DAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

PWM Dimming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Low-Dim Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Phase Shifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 2 Phase-Shifted Outputs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Undervoltage Lockout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Startup Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Stage 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Stage 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Open LED Management and Overvoltage Protection (OVP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Shorted-LED Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

LED Current Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

FLTB Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

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Maxim Integrated | 3

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

TABLE OF CONTENTS (CONTINUED)

Reg Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Register Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

TFT Power Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Boost Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Boost Converter Inductor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Boost Output Filter Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Setting the POS Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

NEG Inverting Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

NEG Regulator Inductor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

NEG External Diode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

NEG Output Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Setting the DGVDD and DGVEE Output Voltages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

LED Driver Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

DC-DC Converter for LED Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Power-Circuit Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Boost Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

SEPIC Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Current-Sense Resistor and Slope Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Output Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

External Switching-MOSFET Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Rectifier Diode Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Feedback Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Typical Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

2

Typical Application Circuit for I C Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Typical Application Circuit for Stand-Alone Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

2

Typical Application Circuit for I C Mode, SEPIC Topology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

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Maxim Integrated | 4

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

LIST OF FIGURES

Figure 1. TFT Sequence with R

= 10kΩ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

SEQ

Figure 2. Phase-Shifted Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

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Maxim Integrated | 5

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

LIST OF TABLES

Table 1. Sequencing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2

Table 2. I C Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

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Maxim Integrated | 6

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Absolute Maximum Ratings

BATT, OUT_, OVP to GND .................................... -0.3V to +52V

NEG, DGVEE to GND.............................................-24V to +0.3V

GND to PGND........................................................-0.3V to +0.3V

GND to LGND1, LGND2........................................-0.3V to +0.3V

GND to DGND .......................................................-0.3V to +0.3V

IN, INN, V , FLTB, DIM, CS, EN, SDA, SCL, ADD to GND-0.3V

CC

to +6V

COMP, NDRV, ISET to GND........................ -0.3V to V

+ 0.3V

CC

REF, FBP, FBNG, FBPG, SEQ to GND.........-0.3V to V + 0.3V

Continuous Power Dissipation ((T = +70°C))

IN

A

LXP, HVINP, BST to GND...................................... -0.3V to +26V

LXP, PGND rms Current Rating............................................ 2.4A

BST to LXP............................................................... -0.3V to +6V

40-Pin TQFN-EP (derate 37mW/°C above +70°C), (Multilayer

Board)..........................................................................2963mW

Operating Temperature Range...........................-40°C to +105°C

Junction Temperature.......................................................+150°C

Storage Temperature Range ..............................-65°C to +150°C

Lead Temperature (soldering, 10s)...................................+300°C

Soldering Temperature (reflow) ........................................+260°C

PGVDD, POS, DP, DN to GND............... -0.3V to V

+ 0.3V

HVINP

LXN to INN ............................................................. -24V to +0.3V

LXN, INN RMS Current Rating.............................................. 1.6A

DGVDD to GND...................................................... -0.3V to +40V

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the

device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for

extended periods may affect device reliability.

Package Information

40-Pin TQFN

Package Code

T4066-5C

21-0141

90-0055

Outline Number

Land Pattern Number

Thermal Resistance, Single-Layer Board:

Junction to Ambient (θ

)

38

1

JA

Junction to Case (θ

)

JC

Thermal Resistance, Four-Layer Board:

Junction to Ambient (θ

)

27

1

JA

Junction to Case (θ

)

JC

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates

RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.

Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal

considerations, refer to www.maximintegrated.com/thermal-tutorial.

Electrical Characteristics

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

INPUT SUPPLY

IN Voltage Range

IN UVLO Threshold

2.8

5.5

V

IN_UVLO_R

Rising

2.45

2.55

100

2.65

IN_UVLO_HY

S

IN UVLO Hysteresis

mV

IN Shutdown Current

IN Quiescent Current

I

EN = GND, V = 3.6V

4

10

µA

IN_SHDN

IN

I

V

EN

= V = 3.6V, no switching

2.2

mA

IN_Q

IN

www.maximintegrated.com

Maxim Integrated | 7

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

REFERENCE

Reference Output

Voltage

V

No load

1.232

1.25

1

1.268

1.2

V

REF_NL

Reference UVLO

Threshold

REF_UVLO_R REF rising

V

Reference UVLO

Hysteresis

REF_UVLO_H

YS

100

10

2

mV

Reference Load

Regulation

REF_LDREG 0 < I

< 100µA

20

5

REF

Reference Line

Regulation

REF_LNREG 2.7V < V < 5.5V

IN

BOOST REGULATOR

Output Voltage Range

POS Voltage Range,

V

> 4V

< 4V

V

IN

+ 1

15

IN

V

HVINP

5

IN

SEQ connected to IN

5

15

2

I C Mode

POS Adjustment Step

Size, I C Mode

SEQ connected to IN

vpos[7:0] = 0x1A

0.1

6.5

V

2

POS Output Regulation

Operating Frequency

Frequency Dither

V

6.37

6.63

POS

swfreq_tft bit = 0 or MAX20069BGTL in

stand-alone mode, dither disabled

f

1900

2200

2500

BOOSTH

kHz

swfreq_tft bit = 1 or MAX20069BGTLA in

stand-alone mode, dither disabled

f

360

430

±4

500

BOOSTL

%

BOOSTD

Oscillator Maximum

Duty Cycle

BOOST_MAX

DC

90

94

98

FBP Regulation Voltage

FBP Load Regulation

FBP Line Regulation

FBP Input Bias Current

V

1.23

1.25

-1

1.27

V

%

FBP

FBP_LDREG 1mA < I

< 100mA

POS

FBP_LNREG

V

= 2.8V to 5.5V

-0.4

20

0

+0.4

200

%

IN

I

V

FBP

= 1.25V, T = +25°C

100

nA

FBP_BIAS

A

Low-Side Switch On-

Resistance

LXP_RON_LS

I

= 0.1A

0.2

0.4

0.5

Ω

LXP

Synchronous Rectifier

On-Resistance

0.25

Synchronous Rectifier

Zero-Crossing

Threshold

ZX_TH

20

mA

LXP Leakage Current

LXP_L_LEAK EN = GND, V

= 15V

20

µA

A

LXP

LXP Current Limit, High

Setting

I

Duty cycle = 80%, lxp_lim_low = 0

Duty cycle = 80%, lxp_lim_low = 1

1.7

2.0

1

2.3

LIMPH

LXP Current Limit, Low

Setting

I

0.74

1.3

A

LIMPL

www.maximintegrated.com

Maxim Integrated | 8

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

Current-limit ramp

MIN

TYP

MAX

UNITS

BOOST_SSTI

ME

Soft-Start Period

10

ms

INVERTING REGULATOR

INN Voltage Range

2.7

5.5

1

V

EN = GND, V

= 3.6V

µA

mA

INN

INN Quiescent Current

I

EN = V

= 3.6V

INN

1

INN

swfreq_tft bit = 0, or MAX20069BGTL in

stand-alone mode, dither disabled

f

1900

360

2200

2500

520

INVL

Operating Frequency

Frequency Dither

kHz

swfreq_tft bit = 1, or MAX20069BGTLA in

stand-alone mode, dither disabled

f

430

±4

INVH

f

%

INV_DITH

Oscillator Maximum

Duty Cycle

INV_MAXDC

94

V

+ V

V

< I

= 2.8V to 5.5V, V

= 7.1V, 1mA

POS

= no load

POS

NEG

NEG_POS_R

EG

INN

-50

7.5

0

70

mV

Regulation Voltage

< 100mA, I

NEG

POS

Inverting-Regulator

Disable Threshold

Above this value on POS, the inverting

regulator is turned off

V

POSth

7.9

0.6

8.2

1.2

20

V

Ω

LXN On-Resistance

LXN Leakage Current

LXN_RON

LXN_LEAK

INN to LXN, I

= 0.1A

LXN

V

IN

= 3.6V, V

= V

= -7V, T =

NEG A

µA

+25°C

LXN Current Limit, High

Setting

I

Duty cycle = 80%, neg_lim_low = 0

Duty cycle = 80%, neg_lim_low = 1

1.2

1.5

1.8

1.1

A

LIMNH

LXN Current Limit, Low

Setting

I

0.55

0.75

5

A

LIMNL

Soft-Start Period

INV_SSTIME Current-limit ramp

ms

POSITIVE CHARGE-PUMP REGULATOR

PGVDD Operating

Voltage Range

V

5

V

PGVDD

HVINP

HVINP-DP Current Limit

Oscillator Frequency

DGVDD Voltage Range,

15

mA

300

400

500

28

kHz

8

V

2

I C Mode

DGVDD Adjustment

Step Size, I C Mode

0.5

16

V

2

DGVDD Output Voltage

I C mode, DGVDD set to 16V (0x10)

15.68

1.23

16.32

1.27

0.2

FBPG Regulation

Voltage

V

1.25

0

V

FBPG_REG

FBPG Line Regulation

V

= 11V to 15V

%/V

nA

Ω

HVINP

FBPG Input Bias

Current

= 1.25V, T = +25ºC

-100

100

60

FBPG

A

DP On-Resistance, High

I

= +10mA

30

DP

www.maximintegrated.com

Maxim Integrated | 9

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

DP On-Resistance, Low

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

I

= -10mA

15

30

Ω

DP

NEGATIVE CHARGE-PUMP REGULATOR

HVINP to DN Current

Limit

15

300

-22

mA

kHz

V

Oscillator Frequency

400

0.5

500

-8

DGVEE Voltage Range,

2

I C Mode

DGVEE Adjustment

V

2

Step Size, I C Mode

DGVEE Output-Voltage

Accuracy

-2

+2

%

FBNG Regulation

Voltage

-12

0

+12

0.2

mV

%/V

nA

FBNG Line Regulation

V

= -11V to -15V

NEG

FBNG Input Bias

Current

V

FBNG

= 0V, T = +25°C

-100

+100

A

DN On-Resistance, High

DN On-Resistance, Low

SEQUENCE SWITCHES

I

= 10mA

30

15

60

30

Ω

DN

I

= -10mA

DN

POS Output-Voltage

Range

V

Tracks HVINP

RON

5

18

V

POS

(HVINP-POS),

= 80mA

POS ON Resistance

1.5

2.6

Ω

POS

I

POS

Expires after soft-start period

Expires after soft start period

120

POS Charge Current

Limit

mA

ILIM

380

6

POS

POS Discharge

Resistance

2

3.4

5

kΩ

ms

V

POS Soft-Start Charge

Time

Current mode (0A to full current limit)

Tracks HVINN

NEG Output-Voltage

Range

V

-7

2

NEG

NEG Discharge

Resistance

3.4

30

50

6

kΩ

Ω

PGVDD On resistance

PGVDD Current Limit

(HVINP-PGVDD), I

= 3mA

60

PGVDD

Expires when PGVDD charging is

completed

15

6

mA

DGVDD Input Voltage

Range

22

17

-6

V

kΩ

V

DGVDD Discharge

Resistance

7

12

DGVEE Input Voltage

Range

-22

www.maximintegrated.com

Maxim Integrated | 10

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

MIN

7

TYP

12

MAX

17

UNITS

kΩ

DGVEE Discharge

Resistance

SEQ Bias Current

I

V

SEQ

= 1V

9.4

10

10.5

µA

SEQ

TFT FAULT PROTECTION

HVINP Undervoltage

Fault

Before the end of POS soft-startup,

75

80

1

85

%

V

2

V

falling, I C mode

HVINP

2

POS Undervoltage-Fault

Threshold

After POS soft startup, V

mode

falling, I C

POS

NEG Undervoltage-Fault

Threshold

V

rising (% of POS setting)

falling, stand-alone mode

75

85

NEG

FBP Undervoltage-Fault

Threshold

0.95

160

75

1.05

260

85

FBP

FBPG Undervoltage-

Fault Threshold

falling, stand-alone mode

rising, standalone mode.

1

V

FBPG

FBNG

FBNG Undervoltage

Fault

210

80

50

40

73

40

mV

%

ms

%

DGVDD Undervoltage

Fault

2

I C mode, DGVDD falling

DGVEE Undervoltage

Fault

2

I C mode, DGVEE rising

75

85

Undervoltage-Fault

Timer

HVINP Short-Circuit

Fault

Before end of POS soft-start, HVINP

30

70

30

50

76

50

2

falling, I C mode

FBP Short-Circuit Fault

Threshold

V

FBP

falling, stand-alone mode

POS Overload Fault

Threshold

POS_OL

POS falling (% of V

)

HVINP

NEG Short-Circuit Fault

Threshold

V

NEG

rising (% of POS setting)

LED BACKLIGHT DRIVER

4.5

42

Input Voltage Range

V

BATT

V

= V

5.5

BATT

CC

Quiescent Supply

Current

= 5V, V

= 1.3V, OUT1–OUT4

OVP

DIM

BATT_IQ

5

8

mA

open

Standby Supply Current

Undervoltage Lockout

BATT_ISHDN Backlight block disabled

1

µA

V

UVLO

V

BATT

rising, V = 5V

DIM

3.7

4.8

4.15

500

4.45

BATT

Undervoltage-Lockout

Hysteresis

UVLO

BATTHY

S

mV

V

CC

REGULATOR

5.75V < V

< 36V, I

= 2.2μF

= 1mA to

VCC

BATT

Output Voltage

V

CC

5

5.2

V

10mA, C

VCC

www.maximintegrated.com

Maxim Integrated | 11

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

Dropout Voltage

Undervoltage

SYMBOL

VCC

CONDITIONS

= 4.5V, I = 5mA

MIN

TYP

MAX

UNITS

V

0.05

0.12

V

DROP

BATT

VCC

V

CC

UVLOVCCR

UVLOVCCF

4.05

3.75

4.2

3.9

50

4.35

4.04

V

Lockout, Rising

V

CC

Undervoltage

Lockout, Falling

Short-Circuit Current

Limit

I

V

shorted to GND

CC

mA

VCC_SC

BOOST/SEPIC CONTROLLER

Switching Frequency

f

Dither disabled

1980

2200

40

2420

kHz

ns

SW

Minimum Off-Time

t

Switching frequency 2.2MHz

Current ramp added to CS

OFF_MIN

Frequency Dither

f

±6

%

DITH

SLOPE COMPENSATION

Peak Slope-

Compensation Current

Ramp Per Cycle

I

42

50

60

µA

SLOPE

CS LIMIT COMPARATOR

CS Threshold Voltage

CS Input Current

V

380

-1

410

440

+1

mV

µA

CS_MAX

I

CS

ERROR AMPLIFIER

OUT_ Regulation High

Threshold

V

falling

rising

0.9

0.97

0.72

1.05

0.81

V

OUT_UP

OUT_

OUT_ Regulation Low

Threshold

V

0.65

OUT_DOWN

OUT_

Transconductance

COMP Sink Current

COMP Ssource Current

MOSFET DRIVER

G

400

200

700

480

880

800

µS

µA

M

I

V

= 2V

= 1V

COMP_SINK

COMP

I

COMP_SRC

COMP

R

I

= -20mA

= +20mA

1.2

1.5

2

3

NDRV_LS

NDRV

NDRV On-Resistance

Ω

R

NDRV_HS

NDRV

LED CURRENT SINK

ISET Resistance Range

R

10

143.5

96

75

kΩ

ISET

I

R

= 10kΩ

= 15kΩ

150

100

156.5

104

Full-Scale OUT_ Output

Current

OUT_

ISET

mA

I

OUT100

ISET

Full scale OUT_output

Current

I

R

= 30kΩ

= 75kΩ

47.5

50

52.5

mA

OUT50

OUT20

ISET

Full-Scale OUT_ Output

Current

R

17.5

1.22

20

22.5

1.28

mA

V

ISET Output Voltage

V

1.25

ISET

www.maximintegrated.com

Maxim Integrated | 12

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

= 150mA

MIN

TYP

MAX

UNITS

I

OUT_MATCH1

50

I

-2.2

+2.2

OUT_

Current Regulation

Between Strings

%

OUT_MATCH5

0

= 50mA

-2.5

+2.5

12

OUT_

Current-Setting

Resolution

I

0.5

8

%

OUT_LSB

V

= 48V, DIM = 0, all OUT_ pins

OUT_

OUT_ Leakage Current

I

µA

OUT_LEAK

shorted together

I

Rise Time

Fall Time

I

10% to 90% I

90% to 10% I

150

50

ns

OUT_

OUT_TR

OUT_

I

OUT_TF

LED FAULT DETECTION

2

I C mode, bit configuration = 11 (00:

short detection disabled), default value in

stand-alone mode

LED-Short-Detection

Threshold

V

7.3

7.8

8.3

V

THSHRT

LED Short-Detection

Threshold

2

V

I C mode, led_short_th[1:0] = 10

5.6

2.8

6

3

6.4

3.2

V

THSHRT

LED-Short-Detection

Threshold

2

I C mode, led_short_th[1:0] = 01

LED-Short-Detection

Disable Threshold

V

All active OUT_s rising

2.8

60

V

THSHRT_DIS

OUT_CKLED

OUT_ Check-LED-

Source Current

I

45

70

µA

mV

V

OUT_ Short-to-GND

Detection Threshold

V

250

1.15

250

300

1.25

300

7

350

1.35

350

OUT_GND

OUT_ Unused-Detection

Threshold

V

OUT_UN

OUT_ Open-LED-

Detection Threshold

V

mV

μs

OUT_OPEN

Shorted-LED-Detection

Flag Delay

t

SHRT

OVERVOLTAGE AND UNDERVOLTAGE PROTECTION

Overvoltage-Trip

Threshold

V

rising

1.18

1.23

70

1.28

V

OVPTH

OVP

Overvoltage Hysteresis

OVP Input Bias Current

V

mV

nA

OVPHYS

I

0 < V

< 1.3V

OVP

-500

+500

0.45

OVP

Undervoltage-Trip

Threshold

V

OVP

falling

0.405

0.425

10

V

OVPUVLO

Boost Undervoltage-

Detection Delay

OVPUVLO_B

LK

µs

ms

Boost Undervoltage-

Blanking Time

After soft-startup

60

www.maximintegrated.com

Maxim Integrated | 13

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

LOGIC INPUTS and OUTPUTS (EN, SCL, ADD, SDA, DIM)

EN Blanking Time

EN_BLK

10

µs

V

DIM Input, Logic-High

DIM Input, Logic-Low

DIM Input Hysteresis

DIM Pullup Current

V

2.1

DIM_IH

V

0.8

V

DIM_IL

V

300

5

mV

µA

DIM_HYS

I

DIM_PUP

EN, ADD Input, Logic-

High

2.1

V

EN, ADD Input, Logic-

Low

0.8

SCL, SDA Input, Logic-

High

0.38 x

V

IN

SCL, SDA Input, Logic-

Low

0.11 x

V

µA

V

IN

Input Current

-1

+1

2

SEQ Level to Set I C

0.92 x

V

IN

Mode

FLTB, SDA Output Low

Voltage

V

Sinking 5mA

5.5V

0.4

+1

V

µA

kHz

%

OL

FLTB, SDA Output

Leakage Current

I

-1

LEAK

FLTB Frequency for

Fault Detection

f

0.84

0.97

25

1.08

FLTB

FLTB Pin Duty Cycle on

LED String Fault

FLTB_DLED Stand-alone mode

Stand-alone mode; fault on at least one

FLTB Pin Duty Cycle on

TFT-Rail Fault

FLTB_DTFT

of the POS, NEG, DGVDD, or DGVEE

pins

75

50

0

%

FLTB Pin Duty Cycle on

LED String and TFT-Rail

Fault

Stand-alone mode, fault on at least one

of the POS, NEG, DGVDD, or DGVEE

pins, and LED driver

FLTB_D

FLTB Duty Cycle on

Thermal-Shutdown

Event

FLTB continuously low

THERMAL WARNING/SHUTDOWN

Thermal-Warning

Threshold

T

Backlight only, T

Backlight only

125

10

°C

WARN

RISING

Thermal-Warning

Hysteresis

T

WARN_HYS

Thermal-Shutdown

Threshold

T

160

15

SHDN

RISING

Thermal-Shutdown

Hysteresis

T

SHDN_HYS

www.maximintegrated.com

Maxim Integrated | 14

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Electrical Characteristics (continued)

(V = 3.3V, V

IN

= 12V, Typical operating circuit (Figure 5), T = T = -40°C to +105°C, unless otherwise noted. Typical values are

BATT

A J

at T = +25°C.)

A

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

2

I C INTERFACE

Clock Frequency

f

1

MHz

ns

SCL

Setup Time (Repeated)

START

t

(Note 1)

260

SU:STA

Hold Time (Repeated)

START

t

ns

HD:STA

SCL Low Time

SCL High Time

Data Setup Time

Data Hold Time

t

(Note 1)

500

260

50

ns

LOW

t

HIGH

t

SU:DAT

HD:DAT

t

0

Setup Time for STOP

Condition

(Note 1)

260

ns

SU:STO

Spike Suppression

50

Note 1: Note 1: Limits are 100% tested at T = +25°C. Limits over the operating temperature range and relevant supply voltage range

A

are guaranteed by design and characterization.

www.maximintegrated.com

Maxim Integrated | 15

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Operating Characteristics

(T = 25°C, V = V

= 3.3V, V

= 14V unless otherwise noted.)

A

IN

INN

BATT

www.maximintegrated.com

Maxim Integrated | 16

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Operating Characteristics (continued)

(T = 25°C, V = V

= 3.3V, V

= 14V unless otherwise noted.)

A

IN

INN

BATT

www.maximintegrated.com

Maxim Integrated | 17

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Operating Characteristics (continued)

(T = 25°C, V = V

= 3.3V, V

= 14V unless otherwise noted.)

A

IN

INN

BATT

www.maximintegrated.com

Maxim Integrated | 18

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Operating Characteristics (continued)

(T = 25°C, V = V

= 3.3V, V = 14V unless otherwise noted.)

A

IN

INN

BATT

Pin Configuration

MAX20069B

TOP VIEW

29 28 27 26 25 24 23 22 21

30

20

19

18

17

LGND1

ISET

SCL

V

31

32

33

CC

BATT

PGND

LXP

34

35

36

SDA

MAX20069B

16 DIM

HVINP

POS

15

14

13

12

11

ADD

FLTB

REF

37

38

BST

DGVDD

PGVDD

DP

39

40

FBNG

SEQ

+

1

2

3

4

5

6

7

8

9

10

TQFN

6mm x 6mm

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Maxim Integrated | 19

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Pin Description

NAME

FUNCTION

Feedback Input for DGVDD. In stand-alone mode, connect a resistor-divider between DGVDD and

2

1

FBPG

FBP

GND with its midpoint connected to the FBPG pin to set the DGVDD voltage. In I C mode, connect

FBPG to GND.

Feedback Input for HVINP. In stand-alone mode, connect a resistor-divider from the boost output

2

to GND with its midpoint connected to the FBP pin to set the HVINP voltage. In I C mode, connect

FBP to GND.

3

4

5

IN

Supply Input. Connect a 1μF ceramic capacitor from IN to GND for proper operation.

Ground Connection

GND

LXN

DC-DC Inverting Converter Inductor/Diode Connection

Buck-Boost Converter Input. Connect a 1μF ceramic capacitor from INN to GND for proper

operation.

6

7

INN

NEG

Negative Source-Driver Output Voltage

Connects directly to the negative charge-pump output to facilitate DGVEE discharge through an

2

8

DGVEE

internal switch connected between DGVEE and GND. In I C mode, DGVEE is the regulator

feedback pin.

Regulated Charge-Pump Driver for the Negative Charge Pump. Connect to the external flying

capacitor.

9

DN

10

DGND

Digital Ground

Sequencing Programming Pin. In stand-alone mode, connect an appropriate resistor from SEQ to

2

GND to program the desired sequence. When using I C control, connect SEQ to IN (see the

11

12

SEQ

2

description). In standalone mode it is still possible to adjust the OUT_ output current through I C

and read the fault registers.

Feedback Input for the Negative Charge Pump. In stand-alone mode, connect a resistor-divider

from REF to DGVEE, with its midpoint connected to FBNG to set the DGVEE voltage. In I C

2

FBNG

mode, connect FBNG to GND.

13

14

REF

1.25V Reference Output. Connect a 220nF ceramic capacitor from REF to GND.

Active-Low Open-Drain Fault Indication Output. Connect an external pullup resistor from FLTB to

an external supply lower than 5V.

FLTB

2

I C Address Select (see Table 2). In stand-alone mode, this pin is used to select the speed of

15

ADD

startup of the backlight boost converter. Connect to GND for the standard startup. Connect to IN to

select accelerated startup with a final voltage of 1.1V on OVP.

16

17

18

DIM

SDA

SCL

PWM Dimming Input. DIM has an internal pullup to V

.

CC

2

I C Data I/O.

2

I C Clock Input. Connect SCL to ground in stand-alone mode.

Full-Scale LED Current-Adjustment Pin. The resistance from ISET to GND controls the current in

each LED string.

19

ISET

20

21

22

23

24

25

LGND1

OUT1

OUT2

LGND2

OUT3

OUT4

Power-Ground Connection for OUT1 and OUT2

LED String 1 Cathode Connection

LED String 2 Cathode Connection. Connect OUT2 to ground using a 12kΩ resistor if not used.

Power-Ground Connection for OUT3 and OUT4

LED String 3 Cathode Connection. Connect OUT3 to ground using a 12kΩ resistor if not used.

LED String 4 Cathode Connection. Connect OUT4 to ground using a 12kΩ resistor if not used.

LED Driver Output-Voltage-Sensing Input. This voltage is used for overvoltage and undervoltage

protection.

26

OVP

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Maxim Integrated | 20

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Pin Description (continued)

NAME

FUNCTION

LED Driver Switching-Converter Compensation Input. Connect an RC network from COMP to GND

to compensate the backlight boost converter (see the Feedback Compensation section).

27

COMP

LED Driver Current-Sense Connection. Connect a sense resistor from the MOSFET source to

PGND and a further resistor from the MOSFET source to the CS pin to set the slope compensation

(see the Current-Sense Resistor and Slope Compensation section).

28

29

30

CS

EN

Enable Input. When EN is high, the device is enabled. If EN is low for more than 25μs the device is

reset.

Switching nMOSFET Gate-Driver Output. Connect NDRV to the gate of the external switching

power MOSFET. Typically, a small resistor (1Ω to 22Ω) is inserted between the NDRV output and

nMOSFET gate to decrease the slew rate of the gate driver and reduce the switching noise.

NDRV

31

32

V

5V Regulator Output. Place a 2.2μF ceramic capacitor as close as possible to V

and GND.

CC

LED Driver Supply Input. Connect BATT to a 4.75V to 40V supply. Bypass BATT to ground with a

ceramic capacitor.

BATT

33

34

35

36

37

PGND

LXP

Power-Ground Connection

Boost HVINP Converter Switching-Node Connection. Connect LXP to the external inductor.

Input Power for the POS Voltage Rail

HVINP

POS

Positive Source-Driver Output Voltage

BST

Boost Converter High-Side Driver Power Supply. Connect a 0.1μF capacitor from BST to LXP.

DGVDD connects directly to the positive charge-pump output to facilitate DGVDD discharge

2

38

DGVDD

through an internal switch connected between DGVDD and GND. In I C mode, DGVDD is the

regulator feedback pin. In stand-alone mode, DGVDD is used for the discharge function.

Switched Version of HVINP Voltage for the Positive Charge Pump. Provides soft-start control of

the DGVDD output.

39

40

—

PGVDD

DP

Regulated Charge-Pump Driver for Positive Charge Pump. Connect to an external flying capacitor.

Exposed Pad. Connect to a large contiguous copper-ground plane for optimal heat dissipation. Do

not use EP as the only electrical ground connection.

EP

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Maxim Integrated | 21

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Functional Diagrams

Detailed Block Diagram

COMP

OVP

ISET

VCC

1 of 4

V

UP/DOWN

COUNTER

+

THH

PWM

COMP

g_M

DRIVE

LOGIC

NDRV

OUT_

DAC

V

THL

CURRENT

REF.

FAULT

DETECTION

SLOPE

COMP

420mV

CS

5V

REGULATOR

+

BATT

TEMP

WARNING,

SHUTDOWN

PHASE-

SHIFT

LOGIC

VCC

UVLO + BG

LGND1,2

DIM

IN

MAX20069B

PGVDD

DP

BST

400kHz

POSITIVE

CHARGE PUMP

TFT BOOST

CONTROL

440kHz/2.2MHz

LXP

TEMP

WARNING,

SHUTDOWN

PGND

FBP

FBPG

1.25V

DGVDD

HVINP

DGVEE

POSITIVE

SOFT-START

AND

POS

NEG

400kHz

NEGATIVE

CHARGE PUMP

DN

DISCHARGE

ENABLE, CONTROL

AND FAULT LOGIC

NEGATIVE

SOFT-START

AND

FBNG

SEQ

DISCHARGE

DGND

EN

INVERTING

REGULATOR

440kHz/2.2MHz

FLTB

INN

I²C

REFERENCE

1.25V

LXN

REF

GND

EP

ADD

SCL SDA

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Maxim Integrated | 22

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Detailed Description

The MAX20069B is highly integrated TFT power supply and LED backlight driver IC for automotive TFT-LCD

applications. The IC integrates one buck-boost converter, one boost converter, two gate-driver supplies, and a boost/

SEPIC converter that can power one to four strings of LEDs in the display backlight.

The source-driver power supplies consist of a synchronous boost converter and an inverting buck-boost converter

that can generate voltages up to +15V and down to -7V. The positive source-driver can deliver up to 120mA, while

the negative source driver is capable of 100mA. The positive source-driver-supply regulation voltage (V

connecting an external resistor-divider on FBP or through I C. The negative source-driver-supply voltage (V

) is set by

POS

2

) is

NEG

always tightly regulated to -V

between 2.8V and 5.5V.

(down to a minimum of -7V). The source-driver supplies operate from an input voltage

POS

The gate-driver-power supplies consist of regulated charge pumps that generate up to +28V and -21.5V and can deliver

up to 3mA each.

The IC features a quad-string LED driver that operates from a separate input voltage (BATT) and can power up to four

strings of LEDs with 150mA (max) of current per string. The IC features logic-controlled pulse-width modulation (PWM)

dimming, with minimum pulse widths as low as 500ns with the option of phase shifting the LED strings with respect to

each other. When phase shifting is enabled, each string is turned on at a different time, reducing the input and output

ripple as well as audible noise. With phase shifting disabled, each current sink turns on at the same time and allows

parallel connection of current sinks.

The startup and shutdown sequences for all power domains are controlled using one of the seven preset modes that

2

are selectable through a resistor on SEQ. If the SEQ pin is connected to IN (I C control), any sequence can be

controlled using the individual regulator-enable bits. When a regulator other than HVINP is enabled, the HVINP boost is

automatically enabled if not previously active. In this case, the second regulator is enabled when the soft-start of HVINP

has completed.

TFT Power Section

Source-Driver Power Supplies

The source-driver power supplies consist of a boost converter with output switch and an inverting buck-boost converter

that generates up to +15V (max) and down to -7V (min), respectively, and can deliver up to 120mA on the positive

regulator and -100mA on the negative regulator. The positive source-driver power supply’s regulation voltage (V

be set by the resistor-divider on FBP or through the I C interface.

) can

POS

2

The negative source-driver supply voltage (V

) is automatically tightly regulated to -V

. V

cannot be adjusted

NEG

POS NEG

2

independently of V

. In I C mode, V

(and V

) is set by writing to the appropriate register. When HVINP is set

POS

NEG

2

to a voltage greater than 7V in I C mode, the NEG converter should be disabled to avoid damage to the device. If the

NEG output is not needed, the external components can be omitted and INN should be connected to IN; LXN should be

left open and NEG should be connected to GND.

Gate-Driver Power Supplies

The positive gate-driver power supply (DGVDD) generates +28V (max) and the negative gate-driver power supply

(DGVEE) generates -21.5V (min). Both can supply up to 3mA output current. The DGVDD and DGVEE regulation

2

voltages are set independently using external resistor networks or through the I C interface.

Fault Protection

The IC has robust fault and overload protection. In stand-alone mode, if any of the DGVEE, NEG, POS, or DGVDD

outputs fall to less than 80% (typ) of their intended regulation voltage for more than 50ms (typ), or if a short-circuit

condition occurs on any output for any duration, then all outputs latch off (at the same time without any power-down

2

sequence) and a fault condition is set. In I C mode, only the output at fault is automatically disabled.

2

In stand-alone mode, the fault condition is cleared when the EN pin or IN supply are cycled. In I C mode, the fault

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Maxim Integrated | 23

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

condition is cleared when the EN bit of the affected rail is set to 0 or when the EN pin or the IN power supply is cycled.

Both sections (TFT and WLED) have thermal-fault detection; only the section causing the thermal overload is turned off.

Thermal faults are cleared when the die temperature drops by 15°C.

2

When a fault is detected, FLTB goes low in I C mode, while in stand-alone mode the FLTB output pulses at a duty cycle

that indicates the source of the fault.

Output Sequencing Control

The IC’s source-driver and gate-driver outputs (DGVEE, NEG, POS, and DGVDD) can be controlled by the resistor value

2

on the SEQ pin (stand-alone mode), or by the I C interface if SEQ is connected to IN (I C mode). In I C mode, the IC is

2

turned on once one of the rails is activated by means of the appropriate I C command, and the sequence is controlled

2

by the I C commands.

All outputs are brought up with soft-start control to limit the inrush current.

In stand-alone mode, toggling the EN pin from low to high initiates an adjustable preset power-up sequence (see Table

1). Toggling the EN pin from high to low initiates an adjustable preset power-down sequence. The EN pin has an internal

deglitching filter of 7μs (typ).

Note: A glitch in the EN signal with a period less than 7μs is ignored by the internal enable circuitry. After all the TFT

outputs have exceeded their power-good levels, the backlight block is turned on.

Table 1. Sequencing Options

POWER-OFF SEQUENCING

SEQ PIN

RESISTOR

POWER-ON SUPPLY SEQUENCING

(REVERSE ORDER OF POWER-UP)

(t –t IS TIME FROM THE EXPIRATION

1

4

(t –t IS TIME FROM THE INSTANT

5

8

(kΩ ±1%)

OF SOFT-START PERIOD)

WHEN EN IS DRIVEN LOW)

3rd

AFTER

2nd

AFTER

4th AFTER

1st AFTER

4th AFTER

1st AFTER t

(ms)

2nd AFTER t

(ms)

3rd AFTER t

(ms)

1

2

7

t (ms)

4

t (ms)

5

t (ms)

8

t (ms)

3

t (ms)

6

10

30

51

POS

NEG

POS

DGVEE

DGVDD

DGVEE

DGVDD

DGVEE

DGVDD

DGVEE

DGVDD

DGVEE

DGVDD

DGVEE

NEG

POS

NEG

No NEG

output

No NEG

output

68

91

POS

DGVEE

DGVDD

DGVEE

DGVDD

DGVEE

DGVDD

POS

No NEG

output

No NEG

output

DGVDD

DGVEE

DGVDD

DGVEE

110

150

POS NEG

DGVEE

—

POS NEG

DGVEE

DGVDD

NEG

POS

NEG

DGVDD

In the above table:

● t = t = 15ms

1

5

● t = t = 30ms

2

6

● t = t = 45ms

3

7

● t = t = 60ms

4

8

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Maxim Integrated | 24

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Figure 1: TFT Sequence with RSEQ=10k

DGVDD

HVINP

POS

FLTB

EN

NEG

t₁

t₂

DGVEE

t₅

t₃

t₆

t₄

t₇

t₈

500ms

Figure 1. TFT Sequence with R

= 10kΩ

SEQ

Description of the LED Driver Section

The IC also includes a high-efficiency high-brightness LED driver that integrates all the necessary features to implement

a high-performance backlight driver to power LEDs in medium-to-large-sized displays for automotive as well as general

applications. The IC provides load-dump voltage protection up to 52V in automotive applications and incorporates two

major blocks: a DC-DC controller with peak current-mode control to implement a boost or a SEPIC-type switched-mode

power supply and a 4-channel LED driver with 20mA to 150mA constant-current-sink capability per channel.

The IC features constant-frequency, peak current-mode control with programmable slope compensation to control the

duty cycle of the PWM controller. The DC-DC converter implemented using the controller generates the required supply

voltage for the LED strings from a wide input supply range. Connect LED strings from the DC-DC converter output to the

4-channel constant-current-sink drivers (OUT1–OUT4) to control the current through the LED strings. A single resistor

connected from the ISET input to ground adjusts the forward current through all four LED strings. Fine adjustment can

2

be made to the LED current using the I C interface, even in stand-alone mode.

The IC features adaptive voltage control that adjusts the converter output voltage depending on the forward voltage of

the LED strings. This feature minimizes the voltage drop across the constant-current-sink drivers and reduces power

dissipation in the device. The backlight boost and current sinks are enabled when the complete sequence of the TFT bias

section is completed.

The IC provides a very wide (10,000:1) PWM dimming range at 200Hz dimming frequency (with a dimming pulse as

narrow as 500ns possible). The internal dimming signal is derived from the DIM signal or from the phase-shift dimming

2

logic. Phase shifting of the LED strings can be disabled in I C mode by writing to the psen bit in the enable (0x02)

register.

Other advanced features include detection and string disconnect for open-LED strings, partially or fully shorted strings,

and unused strings. Overvoltage protection clamps the converter output voltage to the programmed OVP threshold in the

event of an open-LED condition.

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Maxim Integrated | 25

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

The shorted-LED string threshold is programmable using the led_short_th[1:0] bits in the cnfg_gen (0x01 register (in

stand-alone mode, the threshold is fixed at 7.8V).

2

In I C mode, the FLTB signal asserts low to indicate open-LED, shorted-LED, and overtemperature conditions if they

are not masked. In stand-alone mode, a fault in the backlight section causes FLTB to pulse at 25% duty cycle. Disable

individual current-sink channels by connecting the corresponding OUT_ to LGND_ through a 12kΩ resistor (starting

with OUT4). In this case, FLTB will not indicate an open-LED condition for the disabled channel. The IC also features

overtemperature warning and protection that shuts down the controller if the die temperature exceeds +160°C.

Current-Mode DC-DC Controller

The IC backlight boost is a constant-frequency, current-mode controller designed to drive the LEDs in a boost or SEPIC

configuration. The IC features multiloop control to regulate the peak current in the inductor, as well as the voltage across

the LED current sinks to minimize power dissipation.

The default switching frequency is 2.2MHz, but this can be reduced to 440kHz by setting the bl_swfreq bit in the cnfg_gen

(0x01) register. Programmable slope compensation is used to avoid subharmonic oscillation that can occur at > 50% duty

cycles in continuous-conduction mode.

The external nMOSFET is turned on at the beginning of every switching cycle. The inductor current ramps up linearly

until turned off at the peak current level set by the feedback loop. The peak inductor current is sensed from the voltage

across the current-sense resistor (R ) connected from the source of the external nMOSFET to PGND.

CS

The IC features leading-edge blanking to suppress the external nMOSFET switching noise. A PWM comparator

compares the current-sense voltage plus the slope-compensation signal with the output of the transconductance error

amplifier. The controller turns off the external nMOSFET when the voltage at CS exceeds the error amplifier’s output

voltage (at the COMP pin). This process repeats every switching cycle to achieve peak current-mode control.

In addition to the peak current-mode-control loop, the IC has two other feedback loops for control. The converter output

voltage is sensed through the OVP input, which goes to the inverting input of the error amplifier.

The OVP gain (A

) is defined as V

/V

, or (R17 + R16)/R16. The other feedback comes from the OUT_

OVP

OUT OVP

current sinks. This loop controls the headroom of the current sinks to minimize total power dissipation, while still ensuring

accurate LED current matching. Each current sink has a window comparator with a low threshold of 0.68V and a high

threshold of 0.93V. These comparators drive logic that controls an up/down counter. The up/down counter is updated on

every falling edge of the DIM input and drives an 8-bit digital-to-analog converter (DAC), which sets the reference to the

error amplifier.

8-Bit DAC

The error amplifier’s reference input is controlled with an 8-bit DAC. The DAC output is ramped up during startup to

implement a soft-start function (see the Startup Sequence section). During normal operation, the DAC output range is

limited to between 0.6V and 1.25V. The DAC LSB determines the minimum output-voltage step according to the following

equation.

Equation 1:

V

= V

× A

STEP_MIN

DAC_LSB OVP

where V

gain.

is the minimum output-voltage step, V

is 2.5mV (typ), and A

is the OVP resistor-divider

OVP

STEP_MIN

DAC_LSB

PWM Dimming

The DIM input accepts a pulse-width modulation (PWM) signal to control the luminous intensity of the LEDs and modulate

the pulse width of the LED current. This allows for changing the brightness of the LEDs without the color temperature

shift that sometimes occurs with analog dimming. The DIM input detects the dimming frequency based on the first two

pulses applied to the DIM input after EN goes high. The dimming frequency cannot be changed during normal operation.

If a change of dimming frequency is desired, disable the backlight block, change the DIM frequency, and then re-enable

the backlight block. The DIM signal can be applied before or after the device is enabled, but needs to power on smoothly

(no high-frequency pulses). If the DIM signal turn-on is inconsistent, the DIM signal should be applied first; once the DIM

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Maxim Integrated | 26

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

signal is stable, the backlight block can be enabled. In normal dimming mode, if at least one of the LED current sinks

is turned on, the boost converter switches. If none of the current sinks are on (each current-sink DIM signal is low), the

boost converter stops switching, and the COMP node is disconnected from the error amplifier until one of the LED current

sinks is turned on again.

Low-Dim Mode

The IC's operation mode changes at very narrow dimming pulses to ensure a consistent dimming response of the LEDs.

The IC checks the pulse width of the signal being applied to the DIM input, and if the dimming on-time is lower than 25μs

(typ) for 2.2MHz switching frequency (f ), the IC enters low-dim mode. In this state, the converter switches continuously

SW

and the LED short detection is disabled. When the DIM input is greater than 26μs (typ) for 2.2MHz, the IC goes back

into normal dim mode, enabling the short-LED detection and switching the power FET only when the DIM signal is high.

When the switching frequency is set to 440kHz, the low-dim thresholds become 50μs and 51μs.

Phase Shifting

The IC offers phase shifting of the LED strings. To achieve this, the DIM signal is sampled internally by a 10MHz clock.

When phase shifting is enabled, the sampled DIM input is used to generate separate dimming signals for each LED string

that is shifted in phase. The resolution with which the DIM signal is captured degrades at higher DIM input frequencies;

therefore, dimming frequencies between 100Hz and 3kHz are recommended, although higher dimming frequencies are

technically possible. The phase shift between strings is determined by the following equation.

Equation 2:

360

n

Θ =

where n is the total number of strings being used and θ is the phase shift in degrees. The order of the sequence is fixed,

with OUT1 as the first in the sequence and OUT4 as the last. See Figure 2 for a timing diagram example with phase

shifting enabled.

2

The phase-shifting feature is enabled or disabled with the psen bit. In stand-alone mode (no I C), the psen bit in register

0x02 is set high by default (phase shifting enabled). When phase shifting is disabled, all strings turn on/off at the same

time. If multiple current sinks are being connected in parallel to achieve greater than 150mA per string, phase shifting

should be disabled.

If a fault is detected, resulting in a string being disabled during normal operation, the phase shifting does not adjust. For

example, if all four strings are used, each string is 90 degrees out of phase. If the fourth string is disabled due to a fault,

there will still be 90-degree phase difference between each string.

When disabling unused strings, disable the higher-numbered OUT_ current sinks first.

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Maxim Integrated | 27

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Figure 2 Phase-Shifted Outputs

DIM

I_LED

OUT1 Current

OUT2 Current

OUT3 Current

OUT4 Current

I_LED

Total Current

Figure 2. Phase-Shifted Outputs

Undervoltage Lockout

The WLED section features two UVLOs that monitor the input voltage at BATT and the output of the internal LDO

regulator at V . The backlight boost is active only when both BATT and V

CC

exceed their respective UVLO thresholds.

CC

Startup Sequence

The WLED section startup sequence occurs in two stages, as described in the Stage 1 and Stage 2 sections. The overall

startup time can be selected between slow or fast using the ADD pin in stand-alone mode or the wled_ss_time bit in the

2

fault_masks1 (0x0B) register when using the I C interface. The final boost output voltage differs between the slow and

fast startup modes: when the slow startup mode is selected, the final voltage on the OVP pin is 0.6V, while in the fast

mode the final voltage on OVP is 1.1V.

Stage 1

Assuming the BATT input is above its UVLO and the TFT has completed the startup sequence, the V

regulator begins

CC

to charge up its output capacitor. Once the V

regulator output rises above the V

UVLO threshold, the IC goes

CC

through its power-up checks, including unused string detection and OUT_ short-to-ground detection. To avoid possible

damage, the converter does not start if any OUT_ is detected as shorted to ground.

Any current sinks detected as unused are disabled to prevent a false fault-flag assertion during normal operation. After

these checks have been performed, the converter begins to operate and the output voltage begins to ramp up. The DAC

reference to the error amplifier is stepped upwards until the OVP pin reaches 0.6V (or 1.1V in fast startup mode).

This stage duration is fixed at approximately 50ms (22ms in fast startup mode).

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Maxim Integrated | 28

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Stage 2

The second stage begins once the first stage is complete and the DIM input goes high. During stage 2, the output of the

converter is adjusted until the minimum OUT_ voltage falls within the window comparator limits of 0.68V (typ) and 0.93V

(typ). The output ramp is again controlled by the DAC, which provides the reference for the error amplifier. The DAC

output is updated on each rising edge of the DIM input. If the DIM input is a 100% duty cycle (DIM = high), then the DAC

output is updated once every 10ms.

The total soft-start time can be calculated using the following equation in slow startup mode.

Equation 3:

V

+ 0.81 − 0.6 × A

(

)

LED

OVP

t

= 50ms +

SS

f

× 0.01 × A

DIM

OVP

where t

is the total soft-start time, 50ms is the fixed stage 1 duration, V

is the total forward voltage of the LED

LED

SS

strings, 0.81V is midpoint of the window comparator, A

is the gain of the OVP resistor-divider, f

is the dimming

OVP

DIM

frequency (use 100Hz if the DIM input duty cycle is 100%), and 0.01V is the maximum voltage step per clock cycle of the

DAC.

In fast startup mode (with ADD connected to IN or the wled_ss_time bit in the fault_masks1 (0x0B) register set to 1), the

following equation should be used.

Equation 4:

1.1 × A

− (V

+ 0.81)

OVP

LED

OVP

t

= 22ms +

SS

f

× 0.01 × A

DIM

Open LED Management and Overvoltage Protection (OVP)

On power-up, the IC detects and disconnects any unused current-sink channels before entering the DC-DC converter

soft-start. Disable the unused current-sink channels by connecting the corresponding OUT_ to LGND_ through a 12kΩ

resistor. This avoids asserting the FLTB output for the unused channels. After soft-start, the IC detects open strings and

disconnects them from the internal minimum OUT_ voltage detector. This keeps the DC-DC converter output voltage

within safe limits and maintains high efficiency.

If any LED string is open, the voltage at the open OUT_ goes to GND. The DC-DC converter output voltage then

increases to the overvoltage-protection threshold (at which point the PWM controller is switched off, holding NDRV low)

set by the voltage-divider network connected between the converter output, OVP input, and GND; at that point, any

current-sink output with V

< 300mV (typ) is disconnected from the minimum-voltage detector. Select V

OUT_

OUT_OVP

(which will be the maximum voltage the boost converter can produce) according to the equation below.

Equation 5:

V

> 1.1 × (V

+ 1)

OUT_OVP

LED_MAX

where V

is the maximum expected LED string voltage. V

should also be chosen such that the voltage

OUT_OVP

LED_MAX

at the OUT_ pins does not exceed the absolute maximum rating.

The upper resistor in the OVP resistor-divider (R17) can be selected using the following formula.

Equation 6:

V

OUT_OVP

R17 = R16 × (

− 1)

1.23

where 1.23V is the typical OVP threshold. Ensure that the minimum voltage on the OVP pin is always greater than 0.6V

to avoid the boost converter latching off due to undervoltage by checking the following.

Equation 7:

R16

(V

+ 0.6) ×

> 0.6V

R16 + R17

LED_MIN

where V

is the worst-case minimum LED string voltage. If all strings are detected as open or unused the

LED_MIN

www.maximintegrated.com

Maxim Integrated | 29

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

boost converter is disabled. In this condition the boost undervoltage detection is also disabled to avoid signalling an

undervoltage fault. When this occurs the device is latched off.

2

When an open-LED condition occurs, FLTB is asserted low in I C mode or switches at 25% in stand-alone mode.

For boost-circuit applications, the OVP resistor-divider always dissipates power from the battery, through the inductor

and switching diode. If ultra-low shutdown current is needed in stand-alone mode, a general-purpose MOSFET can be

added between the bottom OVP resistor and ground, with the EN of the device controlling the gate of the MOSFET. This

additional MOSFET disconnects the OVP resistor-divider path when the device is disabled.

Shorted-LED Detection

The IC checks for shorted LEDs at each rising edge of DIM. An LED short is detected at OUT_ if the OUT_ voltage is

greater than the value programmed using the led_short_th bits in register 0x01 (or 7.8V in stand-alone mode). Once a

short is detected on any of the strings, the LED strings with the short are disconnected and the FLTB output flag asserts

(unless the fault is masked) until the device detects that the shorts are removed on any of the following rising edges of

DIM. Short-LED detection is disabled in low-dimming mode. If the DIM input is connected high, short-LED detection is

performed continuously.

Short-LED detection is also disabled in cases where all active OUT_ channels rise above 2.8V (typ). This can occur in

a boost-converter application when the input voltage becomes higher than the total LED string voltage drop, such as

during a battery load dump. During a load dump or other input voltage transient an erroneous shorted-LED fault may

be indicated if one of the outputs exceeds the shorted-LED detection threshold before the others. This condition is most

likely to occur when phase-shifting is enabled.

LED Current Control

The IC features four identical constant-current sources used to drive multiple high-brightness LED strings. The current

through each one of the four channels is adjustable between 20mA and 150mA using an external resistor (R

connected between ISET and GND.

)

ISET

Select R

using the formula below.

ISET

Equation 8:

1500

R

=

ISET

I

OUT_

where I

is the desired output current for each of the four channels. All four channels can be paralleled together for

OUT_

2

string currents exceeding 150mA. When I C control is used, the current in the strings can be reduced in steps by writing

to the diout (0x06) register. The resolution of this setting is 0.5% of the value set by the resistor on ISET.

FLTB Output

The FLTB output pin is an active-low, open-drain output that can be used to signal various device faults (for operation in

2

stand-alone mode (see the Stand-Alone Mode section). When the I C interface is used, the FLTB output can flag any or

all of the following conditions:

● Open fault on any of the OUT_ pins

● Shorted-LED fault on any of the OUT_ pins

● Any OUT_ shorted to GND

● LED boost converter undervoltage or overvoltage

● Undervoltage on HVINP, POS, NEG, DGVDD, or DGVEE

● Thermal warning on LED drive section

● Thermal shutdown on either LED drive or TFT bias section

The above conditions can be masked from causing FLTB to go low by using the corresponding mask bit in the

bl_fault_masks (0x0A), fault_masks1 (0x0B), and fault_masks2 (0x0C) registers, if available.

In standalone mode the duty.cycle output on the FLTB pin indicates the type of fault according to the following scheme:

● FLTB continuously low: Thermal-shutdown fault

www.maximintegrated.com

Maxim Integrated | 30

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

● 25% duty cycle on FLTB: Fault in LED section

● 50% duty cycle on FLTB: Faults in both LED and TFT sections

● 75% duty cycle on FLTB: Fault in TFT section

Serial Interface

2

The MAX20069B IC features an I C, 2-wire serial interface consisting of a serial-data line (SDA) and a serial-clock line

(SCL). SDA and SCL facilitate communication between the IC and the master at clock rates up to 1MHz. The master,

typically a microcontroller, generates SCL and initiates data transfer on the bus.

The Slave ID of the MAX20069B depends on the connection of the ADD pin and the selected device version (see Table

2).

2

Table 2. I C Addresses

DEVICE ADDRESS

ADD PIN

CONNECTION

GND

DEVICE

WRITE

ADDRESS

READ

ADDRESS

VERSION

A6

0

A5

1

A4

0

A3

0

A2

0

A1

0

A0

0

MAX20069BGTLA

0x40

0x48

0x41

0x49

IN

0

1

0

1

0

A master device communicates with the MAX20069B by transmitting the correct Slave ID followed by the register address

and data word. Each transmit sequence is framed by a START (S) or Repeated START (Sr) condition, and a STOP (P)

condition. Each word transmitted over the bus is 8 bits long and is always followed by an acknowledge clock pulse.

The IC's SDA line operates as both an input and an open-drain output. A pullup resistor greater than 500Ω is required

on the SDA bus. In general, the resistor has to be selected as a function of bus capacitance such that the rise time on

the bus is not greater than 120ns. The IC's SCL line operates as an input only. A pullup resistor greater than 500Ω is

required on SCL if there are multiple masters on the bus, or if the master in a single-master system has an open-drain

SCL output. In general, for the SCL-line resistor selection, the same SDA recommendations apply. Series resistors in line

with SDA and SCL are optional. The SCL and SDA inputs suppress noise spikes to assure proper device operation even

on a noisy bus.

2

The I C interface can be reset at any time by taking the EN pin low for at least 25μs. When a reset is performed the

registers are reset to their initial values. Since all enable bits will be reset the device outputs will be turned off and a

complete re-initialization will be needed.

www.maximintegrated.com

Maxim Integrated | 31

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Register Map

Reg Map

MAX20069B

ADDRESS

NAME

MSB

LSB

bank 0

0x00

0x01

nop[7:0]

rev_id[3:0]

lxp_lim_l neg_lim_

dev_id[3:0]

bl_swfre

q

swfreq_tf

cnfg_gen[7:0]

led_short_th[1:0]

ssoff_bl

engvee

ssoff_tft

psen

ow

low

t

0x02

0x03

0x04

0x05

0x06

0x07

enable[7:0]

–

enbst

enpos

enneg

engvdd

enblight

vpos_set[7:0]

dgvdd_set[7:0]

dgvee_set[7:0]

diout[7:0]

vpos[7:0]

–

dgvdd[5:0]

–

dgvee[4:0]

neguv

diout[6:0]

pos_ol

bl_fault[7:0]

led_open[3:0]

led_short[3:0]

led_short

gnd

0x08

fault[7:0]

boostuv

–

boostov

–

hvinpuv

–

dgvdduv dgveeuv

wled_th_ wled_th_ tft_th_sh

0x09

0x0A

dev_status[7:0]

–

hw_rst

shdn

warn

dn

bl_fault_masks[7:0]

led_open_mask[3:0]

led_short

fsw_bl+

fsw_bl-

fsw_tft+

fsw_tft-

boostuv_ boostov_

hvinpuv_ wled_ss_ neguv_m dgvdduv dgveeuv

0x0B

0x0C

fault_masks1[7:0]

fault_masks2[7:0]

gnd_mas

k

mask

time

ask

_mask

wled_th_

warn_ma

sk

–

Register Details

nop (0x00)

Device identification register

BIT

7

6

5

4

3

2

1

0

Field

rev_id[3:0]

0x5

dev_id[3:0]

0x9

Reset

Access

Type

Read Only

BITFIELD

rev_id

BITS

7:4

DESCRIPTION

DECODE

Revision ID.

0000: Revision ID

1001: Device ID for the device

dev_id

3:0

Device identification.

cnfg_gen (0x01)

Configuration register

www.maximintegrated.com

Maxim Integrated | 32

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BIT

7

6

5

4

3

2

1

0

neg_lim_lo

w

Field

lxp_lim_low

0b0

led_short_th[1:0]

0x3

bl_swfreq

0b0

ssoff_bl

0b0

swfreq_tft

0x0

ssoff_tft

0x0

Reset

0b0

Access

Type

Write, Read Write, Read

Write, Read

Write, Read Write, Read Write, Read Write, Read

BITFIELD

BITS

DESCRIPTION

DECODE

When set to 1, the LXP switch current limit is

reduced.

lxp_lim_low

7

6

When set to 1, the NEG switch current limit is

reduced.

neg_lim_low

led_short_th

00: Fault disabled

01: Fault threshold is 3V

10: Fault threshold is 6V

11: Fault threshold is 7.8V

5:4

LED fault-detection threshold.

Sets backlight boost switching frequency.

Default value is 2.2MHz.

0: 2.2MHz

1: 440kHz

bl_swfreq

ssoff_bl

3

2

When 1, spread-spectrum modulation is

disabled on the backlight boost; when 0.

spread spectrum is enabled.

0: SS enabled

1: SS disabled

Sets TFT section switching frequency (note

that the charge-pump operating frequency is

always 400kHz). Default value is 2.2MHz.

0: 2.2MHz

1: 420kHz

swfreq_tft

ssoff_tft

1

0

When 1, spread-spectrum modulation is

disabled on the TFT section; when 0, spread

spectrum is enabled.

0: Enabled

1: Disabled

enable (0x02)

Block enables register

BIT

7

–

6

5

4

3

2

1

0

Field

enbst

0x0

enpos

0x0

enneg

0x0

engvdd

0x0

engvee

0x0

enblight

0x0

psen

0x1

Reset

Access

Type

–

Write, Read Write, Read Write, Read Write, Read Write, Read Write, Read Write, Read

BITFIELD

BITS

DESCRIPTION

DECODE

0: Disabled

1: Enabled

enbst

6

Boost converter enable bit.

POS output enable bit. When POS is

enabled, the HVINP boost converter is

automatically enabled if not already active.

0: Disabled

1: Enabled

enpos

5

4

3

2

NEG converter enabled bit. When NEG is

enabled, the HVINP boost converter is

automatically enabled if not already active.

0: Disable

1: Enable

enneg

engvdd

engvee

DGVDD regulator enable bit. When DGVDD

is enabled, the HVINP boost converter is

automatically enabled if not already active.

0: Disabled

1: Enabled

DGVEE regulator enable bit. When DGVEE is

enabled, the HVINP boost converter is

automatically enabled if not already active.

0: disabled

1: enabled

www.maximintegrated.com

Maxim Integrated | 33

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

Backlight boost converter and current sinks

enable bit. If 1, they are enabled when the

TFT section has completed soft-start.

0: Disabled

1: Enabled

enblight

1

LED string phase-shift enable. When 0,

phase shifting between the strings is

disabled. Read only at backlight startup;

thereafter, this bit has no effect.

0: Direct dimming

1: Phase shift

psen

0

vpos_set (0x03)

BIT

Field

7

6

5

4

3

2

1

0

vpos[7:0]

0x14

Reset

Access

Type

Write, Read

www.maximintegrated.com

Maxim Integrated | 34

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

VALUE: POS VOLTAGE

0xA: 5

0xB: 5.1

0xC: 5.2

0xD: 5.3

0xE: 5.4

0xF: 5.5

0x10: 5.6

0x11: 5.7

0x12: 5.8

0x13: 5.9

0x14: 6

0x15: 6.1

0x16: 6.2

0x17: 6.3

0x18: 6.4

0x19: 6.5

0x1A: 6.6

0x1B: 6.7

0x1C: 6.8

0x1D: 6.9

0x1E: 7

0x1F: 7.1

0x20: 7.2

0x21: 7.3

0x22: 7.4

0x23: 7.5

0x24: 7.6

0x25: 7.7

0x26: 7.8

0x27: 7.9

0x28: 8

vpos

7:0

Sets POS output voltage.

0x29: 8.1

0x2A: 8.2

0x2B: 8.3

0x2C: 8.4

0x2D: 8.5

0x2E: 8.6

0x2F: 8.7

0x30: 8.8

0x31: 8.9

0x32: 9

0x33: 9.1

0x34: 9.2

0x35: 9.3

0x36: 9.4

0x37: 9.5

0x38: 9.6

0x39: 9.7

0x3A: 9.8

0x3B: 9.9

0x3C: 10

0x3D: 10.1

0x3E: 10.2

0x3F: 10.3

0x40: 10.4

0x41: 10.5

www.maximintegrated.com

Maxim Integrated | 35

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x42: 10.6

0x43: 10.7

0x44: 10.8

0x45: 10.9

0x46: 11

0x47: 11.1

0x48: 11.2

0x49: 11.3

0x4A: 11.4

0x4B: 11.5

0x4C: 11.6

0x4D: 11.7

0x4E: 11.8

0x4F: 11.9

0x50: 12

0x51: 12.1

0x52: 12.2

0x53: 12.3

0x54: 12.4

0x55: 12.5

0x56: 12.6

0x57: 12.7

0x58: 12.8

0x59: 12.9

0x5A: 13

0x5B: 13.1

0x5C: 13.2

0x5D: 13.3

0x5E: 13.4

0x5F: 13.5

0x60: 13.6

0x61: 13.7

0x62: 13.8

0x63: 13.9

0x64: 14

0x65: 14.1

0x66: 14.2

0x67: 14.3

0x68: 14.4

0x69: 14.5

0x6A: 14.6

0x6B: 14.7

0x6C: 14.8

0x6D: 14.9

0x6E: 15

0x6F-0xFF: 15

dgvdd_set (0x04)

BIT

Field

7

–

6

–

5

4

3

2

1

0

dgvdd[5:0]

0x0

Reset

Access

Type

–

Write, Read

www.maximintegrated.com

Maxim Integrated | 36

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x0: 8

0x1: 8.5

0x2: 9

0x3: 9.5

0x4: 10

0x5: 10.5

0x6: 11

0x7: 11.5

0x8: 12

0x9: 12.5

0xA: 13

0xB: 13.5

0xC: 14

0xD: 14.5

0xE: 15

0xF: 15.5

0x10: 16

0x11: 16.5

0x12: 17

0x13: 17.5

0x14: 18

0x15: 18.5

0x16: 19

0x17: 19.5

0x18: 20

0x19: 20.5

0x1A: 21

0x1B: 21.5

0x1C: 22

0x1D: 22.5

0x1E: 23

0x1F: 23.5

0x20: 24

0x21: 24.5

0x22: 25

0x23: 25.5

0x24: 26

0x25: 26.5

0x26: 27

0x27: 27.5

0x28: 28

0x29- 0x3F: Unused

dgvdd

5:0

Sets DGVDD output voltage.

dgvee_set (0x05)

BIT

Field

7

–

6

–

5

–

4

3

2

1

0

dgvee[4:0]

0x0

Reset

Access

Type

–

Write, Read

www.maximintegrated.com

Maxim Integrated | 37

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x0: -6

0x1: -6.5

0x2: -7

0x3: -7.5

0x4: -8

0x5: -8.5

0x6: -9

0x7: -9.5

0x8: -10

0x9: -10.5

0xA: -11

0xB: -11.5

0xC: -12

0xD: -12.5

0xE: -13

0xF: -13.5

0x10: -14

0x11: -14.5

0x12: -15

0x13: -15.5

0x14: -16

0x15: -16.5

0x16: -17

0x17: -17.5

0x18: -18

0x19: -18.5

0x1A: -19

0x1B: -19.5

0x1C: -20

0x1D: -20.5

0x1E: -21

0x1F: -21.5

dgvee

4:0

Sets DGVEE output voltage.

diout (0x06)

BIT

7

–

6

5

4

3

2

1

0

Field

diout[6:0]

Reset

0x7F

Access

Type

–

Write, Read

www.maximintegrated.com

Maxim Integrated | 38

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x0: 36.5

0x1: 37

0x2: 37.5

0x3: 38

0x4: 38.5

0x5: 39

0x6: 39.5

0x7: 40

0x8: 40.5

0x9: 41

0xA: 41.5

0xB: 42

0xC: 42.5

0xD: 43

0xE: 43.5

0xF: 44

0x10: 44.5

0x11: 45

0x12: 45.5

0x13: 46

0x14: 46.5

0x15: 47

0x16: 47.5

0x17: 48

0x18: 48.5

0x19: 49

0x1A: 49.5

The value in this register sets the percentage 0x1B: 50

diout

6:0

of LED current, with respect to the value

dictated by the resistor on the ISET pin.

0x1C: 50.5

0x1D: 51

0x1E: 51.5

0x1F: 52

0x20: 52.5

0x21: 53

0x22: 53.5

0x23: 54

0x24: 54.5

0x25: 55

0x26: 55.5

0x27: 56

0x28: 56.5

0x29: 57

0x2A: 57.5

0x2B: 58

0x2C: 58.5

0x2D: 59

0x2E: 59.5

0x2F: 60

0x30: 60.5

0x31: 61

0x32: 61.5

0x33: 62

0x34: 62.5

0x35: 63

0x36: 63.5

0x37: 64

0x38: 64.5

www.maximintegrated.com

Maxim Integrated | 39

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x39: 65

0x3A: 65.5

0x3B: 66

0x3C: 66.5

0x3D: 67

0x3E: 67.5

0x3F: 68

0x40: 68.5

0x41: 69

0x42: 69.5

0x43: 70

0x44: 70.5

0x45: 71

0x46: 71.5

0x47: 72

0x48: 72.5

0x49: 73

0x4A: 73.5

0x4B: 74

0x4C: 74.5

0x4D: 75

0x4E: 75.5

0x4F: 76

0x50: 76.5

0x51: 77

0x52: 77.5

0x53: 78

0x54: 78.5

0x55: 79

0x56: 79.5

0x57: 80

0x58: 80.5

0x59: 81

0x5A: 81.5

0x5B: 82

0x5C: 82.5

0x5D: 83

0x5E: 83.5

0x5F: 84

0x60: 84.5

0x61: 85

0x62: 85.5

0x63: 86

0x64: 86.5

0x65: 87

0x66: 87.5

0x67: 88

0x68: 88.5

0x69: 89

0x6A: 89.5

0x6B: 90

0x6C: 90.5

0x6D: 91

0x6E: 91.5

0x6F: 92

0x70: 92.5

0x71: 93

www.maximintegrated.com

Maxim Integrated | 40

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

0x72: 93.5

0x73: 94

0x74: 94.5

0x75: 95

0x76: 95.5

0x77: 96

0x78: 96.5

0x79: 97

0x7A: 97.5

0x7B: 98

0x7C: 98.5

0x7D: 99

0x7E: 99.5

0x7F: 100

bl_fault (0x07)

Backlight LED string faults

BIT

7

6

5

4

3

2

1

0

Field

led_open[3:0]

led_short[3:0]

0x0

Reset

0x0

Access

Type

Read Only

BITFIELD

BITS

DESCRIPTION

DECODE

Each bit of this field corresponds to a string. If

a bit is set to 1, then an open fault has been

detected on the corresponding string and the

string was disabled.

0: Corresponding string is not open

1: Corresponding string is

open or the string is unused or shorted to GND.

led_open

7:4

Each bit of this field corresponds to a string. If

a bit is set to 1, then one or more LEDs in

that string are shorted. This bit is updated at

the beginning of each DIM cycle.

0: Corresponding string has no LED shorted

1: Corresponding string has one or more LEDs

shorted

led_short

3:0

fault (0x08)

TFT fault register

BIT

7

6

5

4

3

2

1

0

led_shortgn

d

Field

boostuv

0x0

boostov

0x0

hvinpuv

0x0

pos_ol

0x0

neguv

0x0

dgvdduv

0x0

dgveeuv

0x0

Reset

0x0

Access

Type

Read Only

BITFIELD

BITS

DESCRIPTION

DECODE

Backlight boost undervoltage status/flag.

When an undervoltage is detected, the boost

is disabled.

0: Not detected so far

1: Event is/was detected

boostuv

boostov

7

Backlight boost overvoltage status flag. When

the overvoltage level is reached, switching

stops but the converter is not disabled.

0: Not detected so far

1: Event is/was detected

6

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Maxim Integrated | 41

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

DECODE

LED string shorted to GND status flag. When

this bit is detected, the converter does not

start and the condition is latched.

0: No LED strings shorted to GND

1: One or more LED strings shorted to GND

led_shortgnd

5

Undervoltage on FBP (external feedback) or

POS (internal feedback). Set immediately if

an undervoltage is detected. If the

undervoltage persists for 50ms, the output is

turned off.

0: No undervoltage is/was detected so far

1: Undervoltage is/was detected

hvinpuv

4

When 1, signals an overload or overcurrent

fault on the POS output.

0: No error is/was detected so far

1: Error is/was detected

pos_ol

neguv

3

2

NEG output undervoltage status flag. Set

immediately when an undervoltage is

detected. If the condition persists for 50ms,

the output is turned off.

0: No undervoltage is/was detected

1: Undervoltage is/was detected

DGVDD undervoltage status flag. This bit is

set immediately when an undervoltage is

detected. If the condition persists for 50ms,

the output is turned off.

0: No undervoltage is/was detected

1: Undervoltage is/was detected

dgvdduv

dgveeuv

1

0

DGVEE undervoltage status/flag. This bit is

set immediately when an undervoltage is

detected. If the condition persists for 50ms,

the output is turned off.

0: No undervoltage is/was detected

1: Undervoltage is/was detected

dev_status (0x09)

Device status bits

BIT

7

–

6

–

5

–

4

–

3

2

1

0

wled_th_sh wled_th_wa

Field

hw_rst

0x1

tft_th_shdn

0x0

dn

rn

Reset

0x0

Access

Type

Read

Clears All

Read Only

BITFIELD

hw_rst

BITS

DESCRIPTION

DECODE

This flag reports if a POR took place since

the last time this bit was reset. It is reset

when this register is read.

0: No POR since last read

1: This is the first read of this register after a POR.

3

wled_th_shd

n

0: No thermal shutdown

1: Backlight driver is in thermal shutdown

2

1

0

LED driver thermal-shutdown status flag.

LED driver thermal-warning status flag.

TFT section thermal-shutdown status flag.

0: Device junction temperature is below 125 °C

1: Device junction temperature is equal to or

greater than 125 °C

wled_th_war

n

0: No thermal shutdown

1: TFT section is in thermal shutdown

tft_th_shdn

bl_fault_masks (0x0A)

Backlight LED string masks for fault bits

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Maxim Integrated | 42

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BIT

Field

7

6

5

4

3

2

1

0

led_open_mask[3:0]

0x0

fsw_bl+

0x0

fsw_bl-

0x0

fsw_tft+

0x0

fsw_tft-

0x0

Reset

Access

Type

Write, Read

BITS

Write, Read Write, Read Write, Read Write, Read

BITFIELD

DESCRIPTION

This field contains masks for the corresponding led_open flags. A bit set to 1

in this field implies that the corresponding status flag will not cause the FLTB

pin to assert.

led_open_mask

7:4

When this bit is set the nominal switching frequency of the backlight boost

converter is increased by 8.5%.

fsw_bl+

fsw_bl-

fsw_tft+

fsw_tft-

3

2

1

0

When this bit is set the nominal switching frequency of the backlight boost

converter is reduced by 8.5%.

When this bit is set the nominal switching frequency of the TFT section is

increased by 8.5%.

When this bit is set the nominal switching frequency of the TFT section is

reduced by 8.5%.

fault_masks1 (0x0B)

TFT masks for fault bits

BIT

7

6

5

4

3

2

1

0

boostuv_ma boostov_ma led_shortgn hvinpuv_ma wled_ss_tim neguv_mas dgvdduv_m dgveeuv_m

Field

sk

d_mask

sk

e

k

ask

Reset

0x0

Access

Type

Write, Read Write, Read Write, Read Write, Read Write, Read Write, Read Write, Read Write, Read

BITFIELD

BITS

DESCRIPTION

DECODE

boostuv_mas

k

Mask for backlight boost undervoltage status

flag.

0: Boost UV will cause FLTB pin assertion

1: Boost UV will not cause FLTB pin assertion

7

boostov_mas

k

Mask for backlight boost overvoltage status

flag.

0: Boost OV will cause FLTB pin assertion

1: Boost OV will not cause FLTB pin assertion

6

5

0: A short-to-ground fault will cause FLTB pin

assertion

1: A short-to-ground fault will not cause FLTB pin

assertion

led_shortgnd

_mask

Mask for led_shortgnd status flag.

0: A HVINP UV fault will cause FLTB pin assertion

1: A HVINP UV fault will not cause FLTB pin

assertion

hvinpuv_mas

k

4

3

2

1

Mask for HVINP undervoltage status flag.

0: Standard 50ms soft-start with final value of 0.6V

on OVP.

1: Accelerated start-up (22ms) with final value of

1.1V on OVP.

Backlight boost soft-start and final voltage

setting.

wled_ss_time

neguv_mask

0: A NEG UV fault will cause FLTB pin assertion

1: A NEG UV fault will not cause FLTB pin

assertion

Mask for NEG undervoltage status flag.

Mask for DGVDD undervoltage status flag.

0: A DGVDD UV fault will cause FLTB pin

assertion

1: A DGVDD UV fault will not causeFLTB pin

assertion

dgvdduv_ma

sk

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Maxim Integrated | 43

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

BITFIELD

BITS

DESCRIPTION

Mask for DGVEE undervoltage status flag.

DECODE

0: A DGVEE UV fault will cause FLTB pin assertion

1: A DGVEE UV fault will not cause FLTB pin

assertion

dgveeuv_ma

sk

0

fault_masks2 (0x0C)

Masks for ofaults contained in register dev_status

BIT

7

–

6

–

5

–

4

–

3

–

2

–

1

0

–

wled_th_wa

rn_mask

Field

Reset

0x0

Access

Type

Write, Read

BITFIELD

BITS

DESCRIPTION

DECODE

0: Status flag will cause FLTB pin assertion

1: Status flag will not cause FLTB pin assertion

wled_th_war

n_mask

1

Mask for wled_th_warn status flag.

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Maxim Integrated | 44

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Applications Information

TFT Power Section

Boost Converter

Boost Converter Inductor Selection

Three key inductor parameters must be specified for operation with the device: Inductance value (L), inductor saturation

current (I ), and DC resistance (R ). To determine the inductance value, first select the ratio of inductor peak-to-

SAT

DC

peak ripple current to average output current (LIR). Higher LIR values mean higher RMS inductor current and therefore

2

higher I R losses. To achieve a lower LIR value, a high-value inductor, which may be physically larger, must be used. A

good compromise between size and loss is to select a 30% to 60% peak-to-peak ripple current to average-current ratio

(LIR from 0.3 to 0.6). If extremely thin high-resistance inductors are used, as is common for LCD-panel applications, the

best LIR may lie between 0.5 and 1.0. The value of the inductor is determined by the following equations.

Equation 9:

V

× D

INA

LIR × I × f

L =

IN SW

using:

Equation 10:

V

× I

OUT OUT

I

=

IN

η × V

INA

V

INA

D = 1 −

V

OUT

where V

is the input voltage, V

is the output voltage, I

is the output current, I is the calculated average

OUT IN

INA

OUT

boost input current, η is the efficiency of the boost converter, D is the duty cycle, and f

is either 440kHz or 2.2MHz

SW

(the selected switching frequency of the boost converter). The efficiency of the boost converter can be estimated from

the Typical Operating Characteristics and accounts for losses in the internal switch, inductor, and capacitors.

The inductor’s saturation rating must exceed the maximum current-limit of 1.7A or 0.74A, depending on the setting of the

lxp_lim_low bit in the cnfg_gen (0x01) register.

Boost Output Filter Capacitor Selection

The primary criterion for selecting the output filter capacitor is low effective series resistance (ESR). The product of the

peak inductor current and the output filter capacitor’s ESR determine the amplitude of the high-frequency ripple seen on

the output voltage. For stability, the boost output-filter capacitor should have a value of 10μF or greater.

To avoid a large drop on HVINP when POS is enabled, the capacitance on the HVINP node should be at least 3 times

larger than that on POS.

Setting the POS Voltage

In stand-alone mode, the POS output voltage is set by connecting FBP to a resistive voltage-divider between HVINP and

GND. Select the lower feedback resistor value and calculate the upper resistor value using the formula below.

Equation 11:

(V

HVINP

− 1.25) × R

LOWER

R

=

UPPER

2

1.25

In I C mode, the POS output is set by writing an 8-bit value to the vpos_set (0x03) register.

The NEG converter outputs a negative voltage whose absolute value is the same as POS. The most negative voltage

the NEG can output is -7V.

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Maxim Integrated | 45

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

NEG Inverting Regulator

NEG Regulator Inductor Selection

The inductor value for the NEG regulator can be selected using the formula below.

Equation 12:

2

V

× (1 − D)

NEG

LIR × I

L =

× f

NEG SW

where V

is the output voltage, I

the output current, LIR the desired inductor ripple ratio, and f

the switching

SW

NEG

frequency.

Calculate the duty-cycle D using:

Equation 13:

V

NEG

D =

V

+ V

IN

NEG

The inductor's saturation current rating must exceed the maximum current-limit setting of 1.2A or 0.6A, depending on the

setting of the neg_lim_low bit in the cnfg_gen (0x01) register.

NEG External Diode Selection

Select a diode with a peak current rating of at least the selected LXN current limit (1.8A or 1.1A) for use with the NEG

output. The diode breakdown-voltage rating should exceed the sum of the maximum INN voltage and the absolute value

of the NEG voltage. A Schottky diode improves the overall efficiency of the converter.

NEG Output Capacitor Selection

The primary criterion for selecting the output filter capacitor is low ESR and capacitance value, as the NEG capacitor

provides the load current when the internal switch is on. The voltage ripple on the NEG output has two components:

● Ripple to due ESR which is the product of the peak inductor current and the output filter capacitor’s ESR

● Ripple due to bulk capacitance that can be determined as follows.

Equation 14:

D

I

×

NEG

f

SW

ΔV

=

BULK

C

NEG

For stability, the NEG output capacitor should have a value of 10μF or greater.

Setting the DGVDD and DGVEE Output Voltages

For most applications, a single charge-pump stage is sufficient for both the positive and negative charge pumps. In the

case of DGVDD, the maximum output voltage is then twice the HVINP voltage. For DGVEE, the most negative voltage

is -V

. If necessary, add further stages while maintaining the DGVDD and DGVEE voltages within their permitted

HVINP

operating ranges.

The DGVDD output voltage is set in stand-alone mode with a resistor-divider from DGVDD to GND, with its center

connected to the FBPG pin. After a value for R

is selected, R

can be calculated using the formula below.

UPPER

LOWER

Equation 15:

(DGVDD − 1.25) × R

LOWER

R

=

UPPER

1.25

The DGVEE output voltage is set by connecting a resistor-divider from REF to DGVEE, with its center connected to

FBNG. The control loop forces FBNG to 0V. Select the resistor connected to REF (R ) so that less than 100μA is

REF

drawn from REF (i.e., the value of R

help of Equation 16.

shall be greater than 12.5kΩ). After selecting R

, calculate R

with the

DGVEE

REF

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Maxim Integrated | 46

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Equation 16:

R

× DGVEE

|

REF

R

=

DGVEE

2

1.25

In I C mode, the DGVDD and DGVEE voltages are set by writing a 6-bit value to the dgvdd_set (0x04) register and a

5-bit value to the dgvee_set (0x05) register, respectively.

LED Driver Section

DC-DC Converter for LED Driver

Two different converter topologies are possible with the DC-DC controller in the device, which has the ground-referenced

outputs necessary to use the constant-current sink drivers. If the LED string forward voltage is always higher than the

input supply voltage range, use the boost converter topology. If the LED string forward voltage falls within the supply

voltage range, use the SEPIC topology.

Note: The boost converter topology provides the highest efficiency.

Power-Circuit Design

First select a converter topology based on the above factors. Determine the required input supply voltage range, the

maximum voltage needed to drive the LED strings, including the worst-case 1V across the constant LED current sink

(V

), and the total output current needed to drive the LED strings (I

) as shown below.

LED

Equation 17:

I

= I

× N

STRING

LED

STRING

where I

is the LED current per string in amperes and N

is the number of strings used. Calculate the

STRING

maximum duty cycle (D

) using the following equations:

MAX

Equation 18 (for the boost configuration):

V

+ V − V

D1 IN_MIN

(

)

LED

D

=

MAX

V

+ V − V

D1

− 0.42

(

)

LED

DS

Equation 18 (for the SEPIC configuration):

V

+ V

D1

(

)

LED

D

=

MAX

V

− V

− 0.42 + V

+ V

(

)

IN_MIN

DS

LED

D1

where V is the forward drop of the rectifier diode in volts (approximately 0.6V), V

is the minimum input supply

IN_MIN

D1

voltage in volts, and V

is the drain-to-source voltage of the external MOSFET in volts when it is on, and 0.42V is the

DS

peak current-sense voltage. Initially, use an approximate value of 0.2V for V

to calculate D

. Calculate a more

DS

MAX

accurate value of D

after the power MOSFET is selected based on the maximum inductor current.

MAX

Boost Configuration

The average inductor current varies with the line voltage and the maximum average current occurs at the lowest line

voltage. For the boost converter, the average inductor current is equal to the input current. Select the maximum peak-to-

peak ripple on the inductor current (ΔIL). The recommended peak-to-peak ripple is 60% of the average inductor current.

Use the following equations to calculate the maximum average inductor current (IL

in amperes.

) and peak inductor current (IL )

P

AVG

Equation 20:

I

LED

I

=

LAVG

1 − D

MAX

Allowing the peak-to-peak inductor ripple ΔIL to be ±30% of the average inductor current:

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Maxim Integrated | 47

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Equations 21:

ΔI = I

× 0.3 × 2

L

LAVG

and

ΔI

L

I

= I

+

LP

LAVG

2

Calculate the minimum inductance value (L

), in henries with the inductor current ripple set to the maximum value.

MIN

Equation 22:

V

− V

− 0.42 × D

(

)

IN_MIN

DS

MAX

L

=

MIN

f

× ΔI

SW

L

where 0.42V is the peak current-sense voltage. Choose an inductor that has a minimum inductance greater than the

calculated L and current rating greater than IL . The recommended saturation current limit of the selected inductor is

MIN

P

10% higher than the inductor peak current for boost configuration.

SEPIC Configuration

Power-circuit design for the SEPIC configuration is very similar to a conventional design, with the output voltage

referenced to the input supply voltage. For SEPIC, the output is referenced to ground and the inductor is split into two

parts (see Typical Application Circuits). One of the inductors (L2) has the LED current as the average current and the

other (L1) has the input current as its average current. Use the following equations to calculate the average inductor

currents (I

, I

) and peak inductor currents (I

, I

) in amperes:

L1AVG L2AVG

L1P L2P

Equation 23:

I

× D

× 1.1

MAX

LED

MAX

I

=

L1AVG

1 − D

The factor 1.1 provides a 10% margin to account for the converter losses:

Equation 24:

I

= I

LED

L2AVG

Assuming the peak-to-peak inductor ripple ΔIL is ±30% of the average inductor current:

Equations 25:

ΔI = I

× 0.3 × 2

L1

L1AVG

and

ΔI

L1

I

= I

+

L1P

L1AVG

2

ΔI = I

× 0.3 × 2

L2

L2AVG

and

ΔI

L2

I

= I

+

L2P

L2AVG

2

Calculate the minimum inductance values L1

maximum value as follows:

and L2

in henries with the inductor current ripples set to the

MIN

Equations 26:

V

− V

− 0.42 × D

(

)

IN_MIN

DS

MAX

L1

L2

=

MIN

f

× ΔI

SW

L1

V

− V

− 0.42 × D

)

DS

f

× ΔI

SW

L2

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Maxim Integrated | 48

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

where 0.42V is the peak current-sense voltage. Choose inductors that have a minimum inductance greater than the

calculated L1 and L2 , and current ratings greater than I and I , respectively. The recommended saturation

MIN

L1P

L2P

current limit of the selected inductor is 10% higher than the inductor peak current.

For simplifying further calculations, consider L1 and L2 as a single inductor with L1/L2 connected in parallel. The

combined inductance value and current is calculated as follows:

Equations 27:

L1

× L2

+ L2

MIN

L

=

MIN

and

I

= I

+ I

L1AVG L2AVG

LAVG

where I

represents the total average current through both the inductors, connected together for SEPIC

LAVG

configuration. Use these values in the calculations for the SEPIC configuration in the following sections.

Select coupling capacitor CS so that the peak-to-peak ripple on it is less than 2% of the minimum input supply voltage.

This ensures that the second-order effects created by the series resonant circuit comprising L1, CS, and L2 do not affect

the normal operation of the converter. Use the following equation to calculate the minimum value of CS.

Equation 28:

I

× D

LED

IN_MIN

MAX

× 0.02 × f

CS ≥

V

SW

where CS is the minimum value of the coupling capacitor in farads, I

0.02 accounts for 2% ripple.

is the LED current in amperes, and the factor

LED

Current-Sense Resistor and Slope Compensation

The MAX20069B backlight boost generates a current ramp for slope compensation. This ramp current is in sync with

the switching frequency, starting from zero at the beginning of every clock cycle and rising linearly to reach 50μA at the

end of the clock cycle. The slope-compensating resistor (R ) is connected between the CS input and the source of the

SC

external MOSFET. This adds a programmable ramp voltage to the CS input voltage to provide slope compensation.

Use the following equation to calculate the value of slope-compensation resistance (R ):

SC

Equation 29 (for boost configuration):

(V

− 2 × V

) × R

× 3

LED

IN_MIN

CS

R

=

SC

L

× 50μA × f

× 4

MIN

SW

Equation 30 (for SEPIC and coupled-inductor configurations):

(V

− V

) × R

× 3

LED

L

IN_MIN

CS

× 4

R

=

SC

× 50μA × f

MIN

SW

where V

and V

are in volts, R

and R

are in ohms, L

is in henries, and f

is in hertz. The value of

SW

LED

IN_MIN

SC

CS

MIN

the switch current-sense resistor (R ) can be calculated as follows:

CS

Equation 31 (for the boost configuration):

4 × L

× f

× 0.39 × 0.9

MIN SW

R

=

CS

I

× 4 × L

× f

+ D

× V

− 2 × V

× 3

(

)

LP

MIN SW

MAX

LED

IN_MIN

Equation 32 (for SEPIC and coupled-inductor configurations):

4 × L

× f

× 0.39 × 0.9

MIN SW

R

=

CS

I

× 4 × L

× f

+ D

× V

− V

× 3

(

)

LP

MIN SW

MAX

LED

IN_MIN

where 0.39 is the minimum value of the peak current-sense threshold. The current-sense threshold also includes the

slope-compensation component. The minimum current-sense threshold of 0.4 is multiplied by 0.9 to take tolerances into

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Maxim Integrated | 49

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

account.

Output Capacitor Selection

For all converter topologies, the output capacitor supplies the load current when the main switch is on. The function of

the output capacitor is to reduce the converter output ripple to acceptable levels. The entire output-voltage ripple appears

across the constant-current sink outputs because the LED string voltages are stable due to the constant current. For the

MAX20069B IC, limit the peak-to-peak output-voltage ripple to 200mV to get stable output current.

The ESR, ESL, and the bulk capacitance of the output capacitor contribute to the output ripple. In most applications,

using low-ESR ceramic capacitors can dramatically reduce the output ESR and ESL effects, connecting multiple ceramic

capacitors in parallel to achieve the required bulk capacitance. To minimize audible noise during PWM dimming,

however, it may be desirable to limit the use of ceramic capacitors on the boost output. In such cases, an additional

electrolytic or tantalum capacitor can provide the majority of the bulk capacitance.

External Switching-MOSFET Selection

The external switching MOSFET should have a voltage rating sufficient to withstand the maximum boost output voltage,

together with the rectifier diode drop and any possible overshoot due to ringing caused by parasitic inductance and

capacitance. The recommended MOSFET V voltage rating is 30% higher than the sum of the maximum output voltage

DS

and the rectifier diode drop.

The continuous-drain current rating of the MOSFET (ID), when the case temperature is at the maximum operating

ambient temperature, should be greater than that calculated below.

Equation 33:

2

ID

=

IL

× D

× 1.3

MAX

RMS

AVG

(

√

)

The MOSFET dissipates power due to both switching losses and conduction losses. Use the following equation to

calculate the conduction losses in the MOSFET.

Equation 34:

2

AVG

P

= IL

× D

× R

MAX DS(ON)

COND

where R

is the on-state drain-to-source resistance of the MOSFET. Use the following equation to calculate the

DS(ON)

switching losses in the MOSFET.

Equation 35:

2

IL

× V

LED

× C

× f

GD SW

AVG

1

P

=

×

+

I

SW

2

I

(

)

GON

GOFF

where I

and I

are the gate currents of the MOSFET in amperes when it is turned on and turned off, respectively.

GON

GOFF

C

is the gate-to-drain MOSFET capacitance in farads.

GD

Rectifier Diode Selection

Using a Schottky rectifier diode produces less forward drop and puts the least burden on the MOSFET during reverse

recovery. A diode with considerable reverse-recovery time increases the MOSFET switching loss. Select a Schottky

diode with a voltage rating 20% higher than the maximum boost-converter output voltage and current rating greater than

that calculated in the following equation.

Equation 36:

I = I

× 1 − D

(

× 1.2

MAX

)

D

LAVG

Feedback Compensation

During normal operation, the feedback control loop regulates the minimum OUT_ voltage to fall within the window

comparator limits of 0.8V and 1.1V when LED string currents are enabled during PWM dimming. When LED currents

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Maxim Integrated | 50

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MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

are off during PWM dimming, the control loop turns off the converter and stores the steady-state condition in the form

of capacitor voltages, mainly the output filter-capacitor voltage and compensation-capacitor voltage. When the PWM

dimming pulses are less than 24 switching clock cycles, the feedback loop regulates the converter output voltage to 95%

of the OVP threshold.

The worst-case condition for the feedback loop is when the LED driver is in normal mode regulating the minimum OUT_

voltage. The switching converter small-signal transfer function has a right-half plane (RHP) zero for boost configuration

if the inductor current is in continuous-conduction mode. The RHP zero adds a 20dB/decade gain together with a

90-degree phase lag, which is difficult to compensate.

The worst-case RHP zero frequency (f

) is calculated as follows:

ZRHP

Equation 37 (for boost configuration):

2

V

× 1 − D

(

)

LED

MAX

f

=

ZRHP

π × L × I

LED

Equation 38 (for SEPIC configuration):

2

V

× 1 − D

(

)

LED

MAX

f

=

ZRHP

π × L × I

× D

LED

MAX

where f

is in hertz, V

is in volts, L is the inductance value of L1 in henries, and I

is in amperes. A simple way

LED

ZRHP

LED

to avoid this zero is to roll off the loop gain to 0dB at a frequency less than 1/5 of the RHP zero frequency with a -20dB/

decade slope.

The switching converter small-signal transfer function also has an output pole. The effective output impedance, together

with the output filter capacitance, determines the output pole frequency (f ), calculated as follows:

P1

Equation 39 (for boost configuration):

I

LED

f

=

2π × V

P1

× C

LED

OUT

Equation 40 (for SEPIC configuration):

I

× D

LED

=

2π × V

MAX

× C

f

P1

LED

OUT

where f is in hertz, V

is in volts, I

is in amperes, and C

is in farads. Compensation components (R

OUT COMP

P1

LED

and C

) perform two functions: C

introduces a low-frequency pole that presents a -20dB/decade slope to

COMP

the loop gain, and R

flattens the gain of the error amplifier for frequencies above the zero formed by R

and

COMP

C

. For compensation, this zero is placed at the output pole frequency (f ), so it provides a -20dB/decade slope for

COMP

P1

frequencies above f to the combined modulator and compensator response.

P1

The value of R

needed to fix the total loop gain at f , so the total loop gain crosses 0dB with -20dB/decade slope

P1

COMP

at 1/5 the RHP zero frequency, is calculated as follows.

Equation 41 (for boost configuration):

f

× R

× I

ZRHP

5 × f × GM

CS LED

R

=

COMP

× V

× 1 − D

(

)

P1

COMP

LED

MAX

Equation 42 (for SEPIC configuration):

f

× R

× I

× D

MAX

ZRHP

5 × f × GM

CS LED

R

=

COMP

× V

× 1 − D

(

P1

COMP

LED

MAX

where R

is the compensation resistor in ohms, f

and f are in hertz, R is the switch current-sense resistor

CS

COMP

ZRHP

P2

in ohms, and GM

is the transconductance of the error amplifier (700μS).

COMP

The value of C

is calculated below.

COMP

www.maximintegrated.com

Maxim Integrated | 51

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Equation 43:

1

C

=

COMP

2π × R

× f

COMP Z1

where f is the compensation zero placed at 1/5 of the crossover frequency that is, in turn, set at 1/5 of the f

. If

ZRHP

Z1

the output capacitors do not have low ESR, the ESR zero frequency may fall within the 0dB crossover frequency. An

additional pole may be required to cancel out this pole placed at the same frequency. This is usually implemented by

connecting a capacitor in parallel with C

and R

.

COMP

www.maximintegrated.com

Maxim Integrated | 52

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Application Circuits

2

Typical Application Circuit for I C Mode

D1

L1

BATTERY INPUT

DIM INPUT

C21

C2

DIM

BATT

VCC

TFT POWER

INPUT

IN

C1

C 22

2.2mF

R 17

SEQ

PGVDD

NDRV

CS

C8

D3

D4

C7

OVP

D7

C10

COMP

DP

ISET

R16

R15

R12

C 22

R11

D9

DGVDD

FBPG

LGND1,2

C9

OUT1

OUT2

OUT3

OUT4

VDGVDD

VDGVEE

DGVEE

DN

TFT POWER INPUT

BST

MAX20069B

D5

C10

L3

C 11

D6

C19

D12

D11

LXP

C20

HVINP

FBP

C23

FBNG

REF

PGND

C14

POS

VPOS

GND

EN

C4

ENABLE

INPUT

INN

TFT POWER INPUT

VNEG

SDA

SCL

I²C BUS

NEG

LXN

FAULT

OUTPUT

D2

FLTB

C5

EP

DGND

ADD

L2

C6

www.maximintegrated.com

Maxim Integrated | 53

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Application Circuits (continued)

Typical Application Circuit for Stand-Alone Mode

D1

L1

BATTERY INPUT

DIM INPUT

C21

C2

DIM

BATT

TFT POWER

INPUT

IN

VCC

C1

2.2mF

C 22

R 17

PGVDD

NDRV

CS

C8

D3

D4

C7

OVP

D7

C10

COMP

DP

ISET

R16

R15

R12

C 22

R11

D9

DGVDD

FBPG

LGND1,2

C9

OUT1

OUT2

OUT3

OUT4

VDGVDD

VDGVEE

DGVEE

DN

TFT POWER INPUT

BST

MAX20069B

D5

C10

L3

C 11

D6

C19

D12

D11

LXP

C20

HVINP

C23

FBP

FBNG

PGND

REF

SEQ

C14

POS

INN

VPOS

C4

GND

EN

TFT POWER

INPUT

ENABLE

INPUT

SDA

SCL

NEG

LXN

VNEG

FAULT

OUTPUT

D2

FLTB

C5

EP

DGND

ADD

L2

C6

www.maximintegrated.com

Maxim Integrated | 54

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Typical Application Circuits (continued)

2

Typical Application Circuit for I C Mode, SEPIC Topology

D1

BATTERY INPUT

C2

DIM INPUT

CS

C21

DIM

BATT

TFT POWER

INPUT

IN

VCC

C1

R17

C 22

2.2mF

SEQ

PGVDD

NDRV

CS

C8

D3

D4

C7

OVP

D7

C10

COMP

DP

SETI

R16

R15

R11

D9

R12

DGVDD

FBPG

C 22

LGND1,2

C9

OUT1

OUT2

OUT3

OUT4

VDGVDD

VDGVEE

DGVEE

DN

TFT POWER INPUT

BST

MAX20069B

D5

C10

L3

C 11

D6

C19

D12

D11

LXP

C20

HVINP

FBP

C23

FBNG

REF

PGND

C14

POS

VPOS

GND

EN

C4

ENABLE

INPUT

INN

TFT POWER INPUT

VNEG

SDA

SCL

I²C BUS

NEG

LXN

FAULT

OUTPUT

D2

FLTB

C5

EP

DGND

ADD

L2

C6

www.maximintegrated.com

Maxim Integrated | 55

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Ordering Information

Nominal POS/NEG

2

PACKAGE

CODE

PART

TEMP RANGE

PIN-PACKAGE

7b I C ADDRESS

Switching Frequency

(kHz)

MAX20069BGTL/

V+**

-40°C to

+105°C

T4066-5C 40 TQFN-EP*

T4066Y-6C 40 TQFN-EP*

T4066-5C 40 TQFN-EP*

T4066Y-6C 40 TQFN-EP*

0x20/0x24

2200

430

MAX20069BGTL/

VY+**

-40°C to

+105°C

MAX20069BGTLA/

V+

-40°C to

+105°C

MAX20069BGTLA/

VY+

-40°C to

+105°C

430

/V Denotes an automotive-qualified part.

+Denotes a lead(Pb)-free/RoHS-compliant package.

T = Tape and reel.

*EP = Exposed pad.

Y = Side-wettable (SW) package

**Future product—contact factory for availability.

www.maximintegrated.com

Maxim Integrated | 56

2

MAX20069B

Automotive I C-Controlled 4-Channel 150mA

Backlight Driver and 4-Output TFT-LCD Bias

Revision History

REVISION REVISION

PAGES

DESCRIPTION

CHANGED

NUMBER

DATE

0

9/20

Initial release

—

For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent

licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max

limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.


型号：	MAX20069BGTLAV
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Automotive I2C-Controlled 4-Channel 150mA Backlight Driver and 4-Output TFT-LCD Bias CD
文件：	总57页 (文件大小：945K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MAX20069BGTLAV [MAXIM]

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