© Semiconductor Components Industries, LLC, 2006

July, 2006 − Rev. 3

1

Publication Order Number:

MC34261/D

MC34261, MC33261

Power Factor Controllers

The MC34261/MC33261 are active power factor controllers

specifically designed for use as a preconverter in electronic ballast and

in off−line power converter applications. These integrated circuits

feature an internal startup timer, a one quadrant multiplier for near

unity power factor, zero current detector to ensure critical conduction

operation, high gain error amplifier, trimmed internal bandgap

reference, current sensing comparator, and a totem pole output ideally

suited for driving a power MOSFET.

Also included are protective features consisting of input

undervoltage lockout with hysteresis, cycle−by−cycle current limiting,

and a latch for single pulse metering. These devices are available in

dual−in−lineand surface mount plastic packages.

http://onsemi.com

SEMICONDUCTOR

TECHNICAL DATA

POWER FACTOR

CONTROLLERS

PIN CONNECTIONS

D SUFFIX

PLASTIC PACKAGE

CASE 751

(SO−8)

8

1

8

1

P SUFFIX

PLASTIC PACKAGE

CASE 626

Voltage Feedback

Input 1

2

3

4

8

7

6

5

(Top View)

Compensation

Multiplier Input

Current Sense

Input

Drive Output

Gnd

Zero Current

Detect Input

Device

Operating

Temperature Range

Package

ORDERING INFORMATION

MC34261D

MC34261P

SO−8

Plastic DIP

MC33261D

MC33261P

SO−8

Plastic DIP

Simplified Block Diagram

Voltage

Feedback

Input

Multiplier,

Latch,

PWM,

Timer,

&

Logic

Error Amp

Multiplier

Undervoltage

Lockout

2.5V

Reference

Zero Current Detector

5

8

6

7

4

3

2

1

Drive Output

Gnd

Zero Current

Detect Input

Multiplier

Input

Compensation

Current Sense

Input