ACT6330

Rev0, 02-Apr-08

WLED BIAS DC/DC CONVERTER (REG1)

Innovative Power

TM

- 8 -

www.active-semi.com

Copyright © 2008 Active-Semi, Inc.

ActivePMU

Setting the LED Bias Current

The LED bias current is set by a resistor connected

from FB1 and ground, and regulator is satisfied

when the LED current is sufficient to generate

250mV across this resistor. Once the bias current is

programmed, the LED current can be adjusted us-

ing the ACT6330’s Direct-PWM feature. REG1 is

also compatible with a variety of well-know LED

dimming circuit, such as with a DC control voltage

and a filtered PWM signal.

Board Layout

Typical for all switching power supplies, the layout

is an important step in design, especially at high

peak current and switching frequencies, please re-

fer to PCB Layout Consideration for more informa-

tion.