ZXLD1352

ZXLD1352

Document number: DS33469 Rev. 3 - 2

2 of 21

www.diodes.com

December 2010

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A Product Line of

Diodes Incorporated

Block Diagram

Figure 1. Block Diagram

Pin Description

Name

Pin No.

Description

LX

1

Drain of NDMOS switch

GND

2

Ground (0V)

ADJ

3

Multi-function On/Off and brightness control pin:

• Leave floating for normal operation. (V

• Drive to voltage below 0.2V to turn off output current

• Drive with DC voltage (0.3V<V

OUTnom

• Drive with PWM signal from open-collector or open-drain transistor, to adjust output current.

o

• Connect a capacitor from this pin to ground to define soft-start time. Soft-start time is

approx.0.5ms/nF)

4

5

Input voltage (7V to 30V). Decouple to ground with 1µF of higher X7R ceramic capacitor close to

device

MN

-

+

Comparator

R1

R2

R3

GND

-

+

LX

Current sense circuit

ADJ

L1

D1

5V

Voltage

regulator

Shutdown

circuit

Vref

50k

1.25V

600KHz

C1