AP5726

WHITE LED STEP-UP CONVERTER

AP5726

Document number: DS31845 Rev. 3 - 2

2 of 17

www.diodes.com

July 2010

© Diodes Incorporated

Pin Descriptions

Pin Name

Description

SW

Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI.

GND

GND pin.

FB

Feedback Pin. Reference voltage is 0.31V. Connect cathode of lowest LED and a sense

EN

Converter On/Off Control Input. A high input at EN turns the converter On, and a low input

turns it off. If On/Off control is not needed, connect EN to the input source for automatic

startup. The EN pin cannot be left floating.

OVP

Output Voltage detect pin for over voltage protection.

Input Supply Pin. Must be locally bypassed with 1

μF or 2.2μF to reduce input noise.

Functional Block Diagram

1.2MHz

Oscillator

RAMP

Generator

Σ

-

+

0.31V

VIN

3

FB

Rc

Cc

Comparator

A2

CONTROL

LOGIC

A1

1

Driver

SW

Q1

2 GND

4

EN

Enable

6

OTP

5

OVP