ML0308 Preliminary

______________________________________________________________________________________________________

3/9

Rev. B, July 2005

PIN FUNCTION DESCRIPTION

Pin

Description

LX

(Pin 1)

Switch Pin. This is the drain of the internal power MOSFET. Minimize the metal trace area

connected to this pin to minimize EMI.

GND

(Pin 2)

Ground. Tie this pin directly to the local ground plane.

FB

(Pin 3)

Feedback Pin. Set the output voltage by selecting values for R1 and R2:

V

R

R

R

VOUT

198

.

0

2

2

1

×

+

=

(ML0308A) or

V

R

R

R

VOUT

23

.

1

2

2

1

×

+

=

(ML0308B)

CE

(Pin 4)

This pin is the chip-enable Pin. Ground this pin to shutdown the chip. Apply a clock with

different duty ratio to control brightness of the LEDs.

VIN

(Pin 5)

The external voltage supply is connected to this pin. A high quality reservoir capacitor must

be connected across pin 5 and pin 2 (ground) to achieve the specified output voltage

parameters. A 4.7uF/6.3 V, low ESR capacitor must be connected as close as possible across

pin 5 and pin 2 (ground).

BLOCK DIAGRAM – ML0308A