AP8801

500mA LED Step-down Converter

AP8801 Rev. 4

3 of 11

DECEMBER 2009

DS31765

www.diodes.com

Pin Name

Description

SW

Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to

reduce EMI.

GND

GND pin

SET

Set Nominal Output Current Pin. Configure the output current of the device.

CTRL

Dimming and On/Off Control Input. Input voltage of 0.2V or lower forces the device into low

current standby mode and shuts off the output.

A PWM signal allows the output current to be

adjusted above or below the level set by the resistor connected to SET input pin.

The input impedance is about 50k

Ω, and if the pin is left open V

Input Supply Pin. Must be locally bypassed.

NC

No connection

Block Diagram

Voltage

Regulator

5V

R

CTRL

GND

SET

SW

Sensing

Block

AP8801

PWM/DC

Control

Figure 2: AP8801 Block Diagram

Pin Descriptions