CAT3637 [CATALYST]
6-Channel Programmable High Efficiency Quad-Mode⑩ LED Driver; 6通道可编程高效率四Mode⑩ LED驱动器
| 型号： | CAT3637 |
| 厂家： | 
CATALYST SEMICONDUCTOR |
| 描述： | 6-Channel Programmable High Efficiency Quad-Mode⑩ LED Driver |
| 文件： | 总14页 (文件大小：284K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
CAT3637
6-Channel Programmable High Efficiency
Quad-Mode™ LED Driver
FEATURES
DESCRIPTION
High efficiency 1.33x charge pump
Quad-Mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives 6 LEDs between 30mA and 0mA each
1-wire EZDimTM interface with 2mA step
Power efficiency up to 92%
The CAT3637 is a high efficiency Quad-Mode fractional
charge pump that can drive up to six LEDs program-
mable by a 1-wire digital interface. The inclusion of a
1.33x fractional charge pump mode increases device
efficiency by up to 10% over traditional 1.5x charge
pumps with no added external capacitors.
Low noise input ripple in all modes
“Zero” current shutdown mode
Soft start and current limiting
Low noise input ripple is achieved by operating at a
constant switching frequency which allows the use of
small external ceramic capacitors. The multi-fractional
charge pump supports a wide range of input voltages
from 2.5V to 5.5V.
Short circuit protection
Thermal shutdown protection
Tiny 3mm x 3mm, 16-pad TQFN package
The EN/SET logic input functions as a chip enable and a
digital programming interface for setting the current in the
LED channels. The 1-wire pulse-programming interface
supports 15 linear steps from zero current to 30mA full-
brightness in 2mA steps.
APPLICATIONS
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
The device is available in a tiny 16-pad TQFN 3 x 3mm
package with a maximum height of 0.8mm.
Catalyst Semiconductor’s Quad-Mode 1.33x, charge pump
switching architecture is patented.
ORDERING INFORMATION
Quantity
per Reel
2000 (1)
Package
Marking
Part Number
For Ordering Information details, see page 13.
CAT3637HV3-GT2
JAAM
Note:
(1) NiPdAu Plated Finish (RoHS-compliant)
16-lead TQFN 3mm x 3mm Package
PIN CONFIGURATION
TYPICAL APPLICATION CIRCUIT
(top view)
1µF
1µF
C1-
VIN
C1+ C2-
C2+
16 15 14 13
V
V
OUT
IN
VOUT
LED6
LED5
LED4
LED3
1
2
3
4
12 C2-
C
2.5V
to
5.5V
IN
C
OUT
LED1
LED2
LED3
LED4
LED5
LED6
11 C2+
10 C1-
1µF
CAT3637
1µF
1-Wire
EN/SET
9
C1+
Programming
5
6
7
8
GND
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5033 Rev. A
CAT3637
ABSOLUTE MAXIMUM RATINGS
Parameter
Rating
6
Unit
V
VIN, LEDx, C1±, C2± voltage
VOUT Voltage
7
V
EN/SET Voltage
VIN + 0.7V
-65 to +160
-40 to +150
300
V
Storage Temperature Range
Junction Temperature Range(1)
Lead Temperature
°C
°C
°C
RECOMMENDED OPERATING CONDITIONS
Parameter
Range
Unit
V
VIN
2.5 to 5.5
-40 to +85
0 to 30
Ambient Temperature Range(1)
ILED per LED pin
°C
mA
mA
Total Output Current
0 to 180
ELECTRICAL OPERATING CHARACTERISTICS
(over recommended operating conditions unless specified otherwise) VIN = 3.6V, EN = High, TAMB = 25°C
Symbol Name
Conditions
Min
Typ
Max Units
1x mode, VIN = 4.2V
1.33 x mode, VIN = 3.3V
1.5x mode, VIN = 2.8V
2x mode, VIN = 2.5V
1.5
2.8
3.7
3.8
mA
mA
mA
mA
IQ
Quiescent Current
IQSHDN
Shutdown Current
VEN = 0V
1
µA
%
ILED-ACC LED Current Accuracy
2mA ≤ ILED ≤ 30mA
ILED −ILEDAVG
ILED
±3
±1
ILED-DEV LED Channel Matching
%
1x mode, IOUT = 120mA
1.33x mode, IOUT = 120mA
1.5x mode, IOUT = 120mA
2x mode, IOUT = 120mA
0.5
3.5
3.5
6
Ω
Ω
Ω
Ω
ROUT
Output Resistance (open loop)
Charge Pump Frequency
1.33x and 2x mode
1.5x mode
0.6
0.8
0.8
1.1
1.1
1.4
MHz
MHz
FOSC
ISC_MAX Output short circuit Current Limit
1x to 1.33x or 1.33x to 1.5x or
LEDTH 1.5x to 2x Transition Thresholds at
any LEDx pin
VOUT < 0.5V
80
mA
150
mV
VHYS
TDF
IIN_MAX
1.33x to 1x Transition Hysteresis
Mode Transition Filter Delay
Input Current Limit
VIN - Highest LED VF
VOUT > 1V
400
120
450
mV
µs
mA
EN/DIM Pin
• Internal Pull-down Resistor
• Logic High Level
• Logic Low Level
REN/DIM
VHI
VLO
100
kΩ
V
V
1.3
0.4
TSD
THYS
VUVLO
Thermal Shutdown
Thermal Hysteresis
Undervoltage lockout (UVLO) threshold
150
20
2
°C
°C
V
Typical application circuit with external components is shown on page 1.
Notes:
(1) Package thermal resistance is below 50°C/W when mounted on FR4 board.
Doc. No. MD-5033 Rev. A
2
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
RECOMMENDED EN/SET TIMING
For 2.5 ≤ VIN ≤ 5.5V, over full ambient temperature range -40º to +85ºC.
Symbol
TLO
Name
Conditions
Min
0.2
0.2
1.5
Typ
Max
Units
μs
EN/SET program low time
EN/SET program high time
EN/SET low time to shutdown
LED current settling time
100
THI
μs
TOFF
TD
ms
μs
10
THI
EN/SET
TLO
TOFF
TD
30mA
28mA
LED
Current
6mA
4mA
2mA
2mA
Shutdown
0mA
0mA
Shutdown
Figure 1. EN/SET One Wire Addressable Timing Diagram
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. MD-5033 Rev. A
CAT3637
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Efficiency vs. Input Voltage
100
Efficiency vs. Li-Ion Voltage
100
VF = 3.3V
VF = 3.0V
VF = 3.3V
90
80
70
60
50
40
90
80
70
60
50
40
1.33x
1.5x
1x
2x
Traditional 1.5x
Charge Pump
4.5
4.0
3.5
3.0
2.5
2.0
4.2 4.0 3.8 3.6 3.4 3.2 3.0
INPUT VOLTAGE [V]
INPUT VOLTAGE [V]
LED Current Change vs. Input Voltage
LED Current Change vs. Temperature
10
10
8
8
6
VF = 3.3V
6
4
4
2
2
0
0
-2
-4
-6
-8
-10
-2
-4
-6
-8
-10
5.5 5.0 4.5 4.0 3.5 3.0 2.5
INPUT VOLTAGE [V]
-40 -20
0
20 40
60 80
TEMPERATURE [°C]
Quiescent Current vs. Input Voltage
6.0
VF = 3.3V
5.0
4.0
3.0
2.0
1.0
0.0
5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0
INPUT VOLTAGE [V]
Doc. No. MD-5033 Rev. A
4
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Switching Frequency vs. Temperature
Output Resistance vs. Input Voltage
10
1.2
VF = 3.3V
1.1
8
2x
1.5x Mode
1.0
0.9
0.8
0.7
0.6
6
1.5x
1.33x
4
1.33x, 2x Mode
2
1x
0
5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0
INPUT VOLTAGE [V]
-40 -20
0
20 40 60 80
TEMPERATURE [°C]
Power Up in 1x Mode
Power Up in 1.33x Mode
Power Up in 1.5x Mode
Power Up in 2x Mode
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-5033 Rev. A
CAT3637
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Power Up Delay (1x Mode)
Power Down Delay (1x Mode)
Operating Waveforms in 1x Mode
Switching Waveforms in 1.33x Mode
Switching Waveforms in 1.5x Mode
Switching Waveforms in 2x Mode
Doc. No. MD-5033 Rev. A
6
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
LED Brightness Levels
Foldback Current Limit
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1x Mode
0
100 200 300 400 500
OUTPUT CURRENT [mA]
LED Settling Time
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
7
Doc. No. MD-5033 Rev. A
CAT3637
PIN DESCRIPTION
Pin #
1
Name
LED6
LED5
LED4
LED3
LED2
LED1
VOUT
VIN
Function
LED6 cathode terminal
LED5 cathode terminal
LED4 cathode terminal
LED3 cathode terminal
LED2 cathode terminal
LED1 cathode terminal
2
3
4
5
6
7
Charge pump output, connect to LED anodes
Charge pump input, connect to battery or supply
Bucket capacitor 1, positive terminal
Bucket capacitor 1, negative terminal
Bucket capacitor 2, positive terminal
Bucket capacitor 2, negative terminal
No connect
8
9
C1+
10
11
12
13/14
15
16
TAB
C1-
C2+
C2-
NC
GND
EN/SET
TAB
Ground reference
Device enable (active high) and 1 wire control input
Connect to GND on the PCB
PIN FUNCTION
VIN is the supply pin for the charge pump. A small
1μF ceramic bypass capacitor is required between the
VIN pin and ground near the device. The operating
input voltage range is from 2.5V to 5.5V. Whenever
the input supply falls below the under-voltage
threshold (2V) all the LED channels will be
automatically disabled and the device register are
reset to default values.
GND is the ground reference for the charge pump.
The pin must be connected to the ground plane on the
PCB.
C1+, C1- are connected to each side of the ceramic
bucket capacitor C1.
C2+, C2- are connected to each side of the ceramic
bucket capacitor C2.
EN/SET is the enable and one wire addressable
control logic input for all LED channels. Guaranteed
levels of logic high and logic low are set at 1.3V and
0.4V respectively. When EN/SET is initially taken
high, the device becomes enabled and all LED
currents remain at 0mA. To place the device into zero
current mode, the EN/SET pin must be held low for
more than 1.5ms.
LED1 to LED6 provide the internal regulated
current for each of the LED cathodes. These pins
enter high-impedance zero current state whenever
the device is placed in shutdown mode.
TAB is the exposed pad underneath the package.
For best thermal performance, the tab should be
soldered to the PCB and connected to the ground
plane.
VOUT is the charge pump output that is connected to
the LED anodes. A small 1μF ceramic bypass capa-
citor is required between the VOUT pin and ground
near the device.
Doc. No. MD-5033 Rev. A
8
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
SIMPLIFIED BLOCK DIAGRAM
C
C
C
C
2+
1-
1+
2-
V
IN
V
1x mode (LDO)
1.33x, 1.5x, 2x Charge Pump
OUT
Mode Control
0.8, 1.1MHz
Oscillator
LED1
LED2
LED3
LED4
LED5
LED6
EN/SET
100kꢀ
Serial
Reference
Voltage
Interface
6 Current
Regulators
Current
Setting DAC
Registers
GND
Figure 2. CAT3637 Functional Block Diagram
BASIC OPERATION
At power-up, the CAT3637 starts operating in 1x mode
where the output will be approximately equal to the
input supply voltage (less any internal voltage losses).
If the output voltage is sufficient to regulate all LED
currents, the device remains in 1x operating mode.
If the device detects a sufficient output voltage
to drive all LED currents in 1x mode, it will revert back
to 1x mode. This only applies for changing back to the
1x mode.
If the output voltage is insufficient or falls to a level
where the regulated current cannot be maintained, the
device automatically switches into 1.33x mode (after a
fixed delay time of about 120μs). In 1.33x mode, the
output voltage is approximately equal to 1.33 times the
input supply voltage (less any internal voltage losses).
If the output voltage is still insufficient or falls to a level
where the regulated currents cannot be maintained, the
device will automatically switch to the 1.5x mode (after
a fixed delay time of about 400μs). In 1.5x mode, the
output is approximately equal to 1.5 times the input
supply voltage (less any internal voltage losses).
If the output voltage is still insufficient to drive the
LEDs, it will automatically switch into 2x mode where
the output is approximately equal to 2 times the input
supply voltage (less any internal voltage losses).
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
9
Doc. No. MD-5033 Rev. A
CAT3637
LED Current Setting
The current in each of the six LED channels is
programmed through the 1-wire EN/SET digital control
input. At the initial power-up and once the EN/SET is
set high, the LED current remains at zero in all
channels. On the first EN/SET pulse (positive edge),
the current is set to 2mA in all channels. On each
consecutive pulse, the current is incremented by 2mA.
On the 15th pulse, the current is equal to the full scale
of 30mA. On the following pulse (16th pulse), the
current goes back to zero and the previous sequence
can be repeated. The EN/SET pin can be pulsed at
high frequency 15 times to decrement the current by
2mA or to program the current from 0mA to 30mA.
The maximum EN/SET signal frequency for
programming the LED current is 2.5MHz.
To power-down the device and turn-off all current
sources, the EN/SET input should be kept low for a
duration TOFF of 1.5ms or more. The driver typically
powers-down with a delay of about 1ms.
Figure 3. EN/SET One Wire Addressable Timing Diagram
THI
EN/SET
TLO
TOFF
TD
30mA
28mA
LED
Current
6mA
4mA
2mA
2mA
Shutdown
0mA
0mA
Shutdown
Figure 4. EN/SET Program Increasing / Decreasing LED Current by 2mA
Doc. No. MD-5033 Rev. A
10
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
Unused LED Channels
External Components
For applications with 5 LEDs or less, unused LEDs
can be disabled by connecting the LED pin directly to
VOUT, as shown on Figure 4. If LED pin voltage is
within 1V of VOUT, then the channel is switched off
and a 200μA test current is placed in the channel to
sense when the channel moves below VOUT – 1V.
The driver requires two external 1μF ceramic
capacitors for decoupling input, output, and for the
charge pump. Both capacitors type X5R and X7R are
recommended for the LED driver application. In all
charge pump modes, the input current ripple is kept
very low by design and an input bypass capacitor of
1μF is sufficient.
1µF
1µF
In 1x mode, the device operates in linear mode and
does not introduce switching noise back onto the
supply.
C1-
VIN
C1+ C2-
C2+
V
IN
V
OUT
VOUT
C
2.5V
to
5.5V
IN
C
OUT
LED1
LED2
LED3
LED4
LED5
LED6
1µF
CAT3637
Recommended Layout
1µF
In charge pump mode, the driver switches internally at
a high frequency. It is recommended to minimize trace
length to all four capacitors. A ground plane should
cover the area under the driver IC as well as the
bypass capacitors. Short connection to ground on
capacitors CIN and COUT can be implemented with the
use of multiple via. A copper area matching the TQFN
exposed pad (TAB) must be connected to the ground
plane underneath. The use of multiple via improves
the package heat dissipation.
1-Wire
EN/SET
Programming
GND
Figure 5. Five LED Application
Protection Mode
If an LED is disconnected, the output voltage VOUT
automatically limits at about 5.5V. This is to prevent
the output pin from exceeding its absolute maximum
rating.
If the die temperature exceeds +150°C the driver will
enter a thermal protection shutdown mode. When the
device temperature drops by about 20°C the device
will resume normal operation.
LED Selection
LEDs with forward voltages (VF) ranging from 1.3V to
5.0V may be used with the CAT3637. Selecting LEDs
with lower VF is recommended in order to improve the
efficiency by keeping the driver in 1x mode longer as
the battery voltage decreases.
Figure 6. Recommended Layout
For example, if a white LED with a VF of 3.3V is
selected over one with VF of 3.5V, the CAT3637 will
stay in 1x mode for lower supply voltage of 0.2V. This
helps improve the efficiency and extends battery life.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-5033 Rev. A
CAT3637
PACKAGE OUTLINE DRAWINGS
TQFN 16-Pad 3 x 3mm (HV3)(1)(2)
A
D
e
b
L
E
E2
PIN#1 ID
PIN#1 INDEX AREA
A1
SIDE VIEW
D2
BOTTOM VIEW
TOP VIEW
SYMBOL
MIN
NOM
0.75
MAX
0.80
0.05
A
A
A1
A3
b
0.70
0.00
0.02
0.20 REF
0.25
A1
A3
0.18
2.90
1.40
2.90
1.40
0.30
3.10
1.80
3.10
1.80
FRONT VIEW
D
3.00
D2
E
–
3.00
E2
e
–
0.50 BSC
0.40
L
0.30
0.50
For current Tape & Reel information, download the pdf file from:
http://www.catsemi.com/documents/tapeandreel.pdf
Notes:
(1) All dimensions are in millimeters.
(2) Complies with JEDEC standard MO-229.
Doc. No. MD-5033 Rev. A
12
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3637
EXAMPLE OF ORDERING INFORMATION(1)
Prefix
CAT
Device #
3637
Suffix
HV3
–
G
T2
Product Number
Lead Finish
G: NiPdAu
Tape & Reel
T: Tape & Reel
2: 2000/Reel
3637
Optional
Package
Company ID
HV3: TQFN 3 x 3mm
Notes:
(1) All packages are RoHS-compliant (Lead-free, Halogen-free).
(2) The standard lead finish is NiPdAu.
(3) The device used in the above example is a CAT3637HV3–GT2 (TQFN, NiPdAu, Tape & Reel, 2000 pcs / Reel).
(4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
13
Doc. No. MD-5033 Rev. A
REVISION HISTORY
Date
Rev. Reason
Initial Issue
03/07/2008
A
Copyrights, Trademarks and Patents
© Catalyst Semiconductor, Inc.
Trademarks and registered trademarks of Catalyst Semiconductor include each of the following:
Adaptive Analog™, Beyond Memory™, DPP™, EZDim™, LDD™, MiniPot™, Quad-Mode™ and Quantum Charge Programmable™
Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products.
CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS
PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE
RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING
OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES.
Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a situation where
personal injury or death may occur.
Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled
"Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale.
Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical
semiconductor applications and may not be complete.
Catalyst Semiconductor, Inc.
Corporate Headquarters
2975 Stender Way
Santa Clara, CA 95054
Phone: 408.542.1000
Fax: 408.542.1200
www.catsemi.com
Document No: MD-5033
Revision:
A
Issue date:
03/07/08
相关型号：
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