RT8487

Copyright © 2015 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

DS8487-00

March

2015

www.richtek.com

3

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

VCC

Supply Voltage Input. For good bypass, a ceramic capacitor near the VCC

pin is required.

2

GND

Ground.

3

GATE

Gate Driver Output for External MOSFET Switch.

4

AND

AND Function Pin.

5

VC

Close Loop Compensation Node.

6

SENSE

LED Current Sense Input. The typical sensing threshold is 250mV between

the SENSE and GND pin.

Function Block Diagram

+

-

State Machine

Regulator

A

V

VCC

GATE

GND

AND

VC

SENSE

250mV

EA

Operation

The RT8487 senses true average output current and

keeps the system driving constant output current. The

VC pin is the compensation node in this close loop

system and dominates the frequency response. To

stabilize the system and achieve better PFC / THDi,

proper selection of a compensation network is needed.