1

19

7

6

5

4

3

2

13

14

15

16

17

18

EP

VCC

IREF

AGND

CDHC

VDHC

EN

MODE

NC

NC

NC

IOUT5

IOUT4

IOUT3

IOUT2

IOUT6

NC

IOUT5

NC

IOUT4

NC

IOUT3

NC

IOUT2

NC

IOUT1

NC

PGND

PGND

EN

MODE

DIM

NC

NC

NC

VCC

IREF

AGND

CDHC

VIN

VDHC

FAULTb

OTMb

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

EP

LM3432, LM3432B

SNVS498D – APRIL 2007 – REVISED MAY 2013

www.ti.com

DESCRIPTION CONTINUED

The 6-channel current sink can be adjusted from 15mA to 40mA by an external resistor. Their output drivers can

withstand up to 80V. Digital PWM or analog voltage signal can be used to control the duty cycle of all the

ratio during PWM dimming are ensured.

The LM3432/LM3432B contain LED open/short circuit and over-temperature fault signaling to the system micro-

controller (the LM3432B does not include open circuit fault signaling). These devices are available in a low

profile, thermally enhanced 24 lead WQFN package. The LM3432 is also available in the 28 lead eHTSSOP.

Connection Diagram

Figure 1. Top View

Figure 2. Top View

24 Lead Plastic WQFN-24

28 Lead Plastic eHTSSOP-28

Pin Descriptions

Pin Number

Name

Description

WQFN-24

eHTSSOP-28

1

5

VCC

Internal linear regulator output, needs 680nF minimum for stability.

2

6

IREF

3

7

AGND

Analog ground

4

8

CDHC

An external capacitor to ground programs the Dynamic Headroom Control (DHC)

response time constant.

5

9

VDHC

DHC voltage output. Connecting this output through a gain setting resistor to the DHC

pin of Texas Instruments Semiconductor's LM3430 enables the DHC function.

6

10

EN

Device Enable, active HIGH.

7

11

MODE

Dimming mode select pin. Short to ground for Digital PWM dimming or connect to an

external capacitor to ground for analog dimming.

8

12

DIM

Digital PWM or Analog voltage input for IOUT duty cycle.

9

13

FAULTb

Open drain active LOW output for output fault.

10

14

OTMb

Open drain active LOW over temperature warning output.

12, 13, 15,

15, 17, 19,

IOUT1-6

Constant current sink outputs, adjustable 15mA to 40mA, voltage across this pin can

be up to 80V max.

17, 19, 20

21, 23, 25

22

27, 28

PGND

Power Ground.

24

1

VIN

Supply voltage input, from 6V to 40V.

11, 14, 16,

2, 3, 4, 16, 18,

NC

No connection and should be left open.

18, 21, 23

20, 22, 24, 26

EP

EP

EP

Thermal connection pad, connect directly to GND.

2

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