MAX16939 [MAXIM]

current-mode step-down converter with low operating current;


型号：	MAX16939
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	current-mode step-down converter with low operating current
文件：	总8页 (文件大小：581K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

Click here for production status of speciﬁc part numbers.

Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

General Description

Quick Start

The MAX16936 evaluation kit (EV kit) demonstrates

the MAX16936 high-voltage, current-mode step-down

converter with low operating current. The EV kit operates

over a wide 3.5V to 36V input range and the output is set

for 5V at 2.5A.

Required Equipment

● MAX16936 EV kit

● 14V, 1A DC power supply

● Electronic load capable of 2.5A

● Digital voltmeter (DVM)

The EV kit comes with the MAX16936RAUEA/V+ installed.

Features

Procedure

● Wide 3.5V to 36V Input Supply Range

● Forced-PWM or Skip-Mode Operation

● Programmable Switching Frequency

● Power-Good Output

The EV kit is fully assembled and tested. Follow the steps

below to verify board operation. Caution: Do not turn on

supplies until all connections are made.

1) Verify that jumpers JU1 and JU2 are in their default

positions, as shown in Table 1 and Table 2.

● Proven PCB Layout

2) Connect the power supply between the EXT_VBAT

and nearest PGND test points.

● Fully Assembled and Tested

3) Connect the 2.5A electronic load between the OUT

and nearest PGND test points.

4) Connect the DVM between the OUT and nearest

PGND test points.

5) Turn on the power supply.

6) Enable the electronic load.

Ordering Information appears at end of data sheet.

7) Verify that the voltage at the OUT test point is approxi-

mately 5V.

Table 1. EN Configuration (JU1)

Table 2. Mode of Operation (JU2)

SHUNT

POSITION

DESCRIPTION

POSITION

MODE PIN

MODE

Connects the EN pin to the voltage at SUP

for normal operation.

Forced-PWM mode

(device syncs to the

internal clock)

1-2*

Connected to BIAS

Connects the EN pin to ground to enter

shutdown mode.

2-3

Connected to

AGND

2-3

SKIP mode

*Default position.

Forced-PWM mode

(device syncs to an

external clock)

Connected to an

external clock

Not installed

*Default position.

19-6771; Rev 2; 3/20

Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Setting the Switching Frequency (FOSC)

The EV kit switching frequency is set by a resistor, R

(R2), connected from FOSC to AGND. Refer to Figure 3.

in the MAX16936 IC data sheet for a graphical approach

Detailed Description of Hardware

The EV kit demonstrates the MAX16936 high-voltage,

high-frequency, step-down converter with low operating

current. The EV kit operates over a wide 3.5V to 36V input

range and the output is set for 5V at 2.5A.

FOSC

of selecting the correct R

(R2) value.

FOSC

Power-Good Output (PGOOD)

Enable (EN)

The EV kit provides a PGOOD test point to monitor the

status of the device output. PGOOD asserts when VOUT

rises above 95% of its regulation voltage. PGOOD

deasserts when VOUT drops below 92% of its regulation

voltage.

Place a shunt in the 1-2 position on jumper JU1 for normal

operation. To place the device into shutdown mode, move

the shunt on JU1 to the 2-3 position.

Synchronization Input (FSYNC)

The EV kit features jumper JU2 to control the synchro-

nization input (FSYNC). The device synchronizes to an

external signal applied to FSYNC. Connect FSYNC to

AGND to enable skip-mode operation. Connect to BIAS

or to an external clock to enable fixed-frequency forced-

PWM mode operation.

Output

Connect FB to BIAS for a fixed +5V (EV kit default

output) or a fixed +3.3V output voltage. To set the output

to other voltages between 1V and 10V, connect a resis-

tive divider from output (OUT) to FB to AGND. Use the

following formula to determine the R4 and R6 of the resis-

tive divider network:

To use an external clock, uninstall the shunt on JU2 and

apply the signal at the FSYNC test point. The external

clock frequency at FSYNC can be higher or lower than the

internal clock by 20%. Ensure that the duty cycle of the

external clock used has a minimum 100ns pulse width.









OUT

R4 = R6×

−1





where V = 1V.

Synchronizing Output (SYNCOUT)

The EV kit provides jumper JU3 to pull up the open-drain

SYNCOUT to the OUT voltage. SYNCOUT is a 180° out-

of-phase clock output relative to the internal oscillator

at SYNCOUT to create cascaded power supplies with

multiple MAX16936s.

Maxim Integrated

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Component List

DESIGNATION QTY

DESCRIPTION

DESIGNATION QTY

DESCRIPTION

AGND,

10pF ±5%, 50V C0G ceramic

capacitor (0402)

Black test points

PGND (x4)

C13

Murata GRM1555C1H100J

BIAS,

EXT_SUP,

EXT_VBAT,

FSYNC,

PGOOD, OUT,

SYNCOUT

Not installed, ceramic capacitors

(0402)

C14, C15

Red test points

3A, 60V Schottky diode (SMB)

Diodes Inc. B360B-13-F

JU1, JU2

JU3

3-pin headers

2-pin header

47µF ±20%, 50V aluminum

electrolytic capacitor

(8.00mm x 10.20mm)

2.2µH, 13A inductor

(7mm x 6.9mm)

Würth 744311220

Panasonic EEE-TG1H470UP

4.7µF ±10%, 50V X7R ceramic

capacitors (1210)

Murata GCM32ER71H475KA55L

Not installed, red test point

20kΩ ±1% resistor (0402)

12.1kΩ ±1% resistor (0402)

10kΩ ±5% resistor (0402)

Not installed, resistors (0402)

1kΩ ±5% resistor (0402)

0Ω ±5% resistor (1210)

C2, C4

C3, C5

0.1µF ±10%, 50V X7R ceramic

capacitors (0603)

Murata GCM188R71H104KA57D

R4, R6, R7

0.1µF ±10%, 16V X7R ceramic

capacitor (0402)

Murata GRM155R71C104K

R9, R10, R12

R11

0Ω ±5% resistors (0402)

100kΩ ±5% resistor (0402)

22µF ±10%, 10V X7R ceramic

capacitors (1210)

Murata GCM32ER71A226KE12L

C7, C8

C10

Automotive buck converter

(16 TSSOP-EP*)

Maxim MAX16936SAUEA/V+

2.2µF ±10%, 10V X7R ceramic

capacitor (0603)

Murata GRM188R71A225K

—

Shunts

PCB: MAX16936 EVALUATION

KIT

1000pF ±10%, 50V X7R ceramic

capacitor (0402)

—

C12

Murata GRM155R71H102K

*EP = Exposed pad.

Component Suppliers

SUPPLIER

Diodes Incorporated

PHONE

WEBSITE

805-446-4800

770-436-1300

800-344-2112

201-785-8800

www.diodes.com

Murata Americas

www.murataamericas.com

www.panasonic.com

www.we-online.com

Panasonic Corp.

Würth Electronik GmbH & Co. KG

Note: Indicate that you are using the MAX16936 when contacting these component suppliers.

Maxim Integrated

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Figure 1. MAX16936 EV Kit Schematic

Maxim Integrated

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

1.0”

Figure 3. MAX16936 EV Kit PCB Layout—Component Side

Figure 2. MAX16936 EV Kit Component Placement Guide—

Component Side

Figure 4. MAX16936 EV Kit PCB Layout—Layer 2

Maxim Integrated

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Figure 5. MAX16936 EV Kit PCB Layout—Layer 3

Figure 6. MAX16936 EV Kit PCB Layout—Solder Side

Figure 7. MAX16936 EV Kit Component Placement Guide—

Solder Side

Maxim Integrated

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Ordering Information

PART

TYPE

EV Kit

PACKAGE

TSSOP

TQFN

MAX16936EVKIT#

MAX16936REVKIT#

#Denotes RoHS compliant.

Note: MAX16936EVKIT# can be used for MAX16938 and

MAX16939.

Maxim Integrated

│ 7

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Evaluates: MAX16936/MAX16938/

MAX16939

MAX16936 Evaluation Kit

Revision History

REVISION

NUMBER

REVISION

DATE

PAGES

CHANGED

DESCRIPTION

8/13

4/16

Initial release

—

Added additional ICs that kit can evaluate and updated Ordering Information

1–8

Updated Component List table by replacing with MAX16936SAUEA/V+ in the U1

section

3/20

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.

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

2020 Maxim Integrated Products, Inc.

│ 8

MAX16939 [MAXIM]

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