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MA5603

Major Power Technology Co., Ltd.

Rev.1.4

Aug 24, 2016

38V/2A Synchronous Buck for LED Driver



GENERAL DESCRIPTION

The MA5603 is a monolithic synchronous buck regulator, and step-down converter designed

for driving up to 9 series white LEDs from a 36V system input. The total LED driving current up

to 2A, which is measured through an external current sense resistor. Its low 220mV feedback

voltage reduces power loss and improves efficiency. The MA5603 includes current limit, short

circuit protection and thermal shutdown protection preventing damage.

An internal soft-start prevents inrush current at turn-on, This device, available in an

SOP8L-EP(Exposed pad) package, provides a very compact solution with minimal external

components.



FEATURES

- Wide 8V to 38V Operating Input Range

- Integrated two 140m

Ω Power MOSFET Switches

- Feedback Voltage : 220mV

- Internal Soft-Start / VFB Over Voltage Protection

- Stable with Low ESR Ceramic Output Capacitors

- Fixed 250KHz Frequency

- Current Limit, Thermal Shutdown and Short Circuit Protections (SCP).

- Input Under/Over Voltage Lockout



APPLICATION CIRCUIT

IN

EN

VDD

GND

BS

SW

FB

COMP

11~36V

R4

100kΩ

C5

100nF

L1

22

μH

C3

R3

C4

0.1

μF

C6

0.1

μF

MA5603

R5

24

Ω

3.3nF

2.2kΩ

RSET

1W

WLEDs

0.66Ω

PAD(GND)

C1

100

μF

50V

C2

10

μF

16V

D1

SS34

ON

OFF