SEMICONDUCTOR

TECHNICAL DATA

FC9961

2015. 03. 23

1/7

Revision No : 1

Features

Fast average current control

Programmable constant off-time switching

Linear dimming input

PWM dimming input

Output short circuit protection with skip mode

Pin-compatible with the FC9910B

Applications

DC/DC or AC/DC LED driver applications

LED backlight driver for LCD displays

General purpose constant current source

LED signage and displays

Architectural and decorative LED lighting

LED street lighting

►

►

►

►

►

►

►

►

►

►

►

►

►

General Description

The FC9961 is an average current mode control LED driver

IC operating in a constant off-time mode. Unlike FC9910B,

this control IC does not produce a peak-to-average error, and

therefore greatly improves accuracy, line and load regulation

of the LED current without any need for loop compensation or

high-side current sensing. The output LED current accuracy

is ±3%.

The IC is equipped with a current limit comparator for hiccup-

mode output short circuit protection.

The FC9961 can be powered from an 8.0 - 450V supply.

A PWM dimming input is provided that accepts an external

control TTL compatible signal. The output current can be

programmed by an internal 250mV reference, or controlled

externally through a 0 - 1.5V dimming input.

FC9961 is pin-to-pin compatible with FC9910B and it can

be used as a drop-in replacement for many applications to

improve the LED current accuracy and regulation.

Typical Application Circuit

LED Driver with Average-Mode Constant Current Control

1

4

2

8

5

6

7

3

VIN

GATE

PWMD

LD

VDD

RT

CS

GND

LED

Load

Sets

LED

Current

8.0 - 450VDC

R

CS

R

T