Ver: 0.6 Preliminary

May 10, 2006

TEL: 886-3-5788833

http://www.gmt.com.tw

8

G5105

Global Mixed-mode Technology Inc.

Pin Description

PIN

NAME

FUNCTION

1

SW

Switch Pin

. The drain of the internal NMOS power switch. Connect this pin to inductor.

2

GND

Ground Pin

.

3

FB

Feedback Pin

.

4

SHDN

Active Low Shutdown Pin

.

5

COMP

Compensation Pin

.

6

VCC

Input Supply Pin

. Bypass this pin with a capacitor as close to the device as possible.

Block Diagram

+

VREF

SW

FB

1.28V

GND

CONTROL

DRIVER

+

OC

SHDN

R

S

Q

1MHz

OSCILLATOR

VCC

COMPARATOR

A2

+

A1

RAMP

GENERATOR

M1

COMP

+

VREF

SW

FB

1.28V

GND

CONTROL

DRIVER

+

OC

SHDN

R

S

Q

1MHz

OSCILLATOR

VCC

COMPARATOR

A2

+

A1

RAMP

GENERATOR

M1

COMP

White LED Driver

D2

(Optional)

C2

D1

L1

VCC

G5105

SHDN

FB

COMP

V

IN

C1

ON OFF

SW

GND

V

OUT

R2

R1

R4

R3

M1

R

C

C

C

V

BIAS

V

DIM

PWM Dimming

White LED Driver

D2

(Optional)

C2

D1

L1

VCC

G5105

SHDN

FB

COMP

V

IN

C1

ON OFF

SW

GND

V

OUT

R2

R1

R4

R3

M1

R

C

C

C

V

BIAS

V

DIM

PWM Dimming