1

FEATURES

APPLICATIONS

DESCRIPTION

V

IN

V

OUT

12V to 21V

M2

R

B

R

A

R

B

M1

L2

D2

D1

C

OUT

R

A

C

PC

C

PC

C

ZC

C

ZC

R

ZC

R

ZC

C

SS

R

RDM

R

RT

T1

T2

C

CDR

R

DMX

R

SYN

C

REF

R

PK1

R

PK2

C

ZV

R

ZV

C

PV

R

S

R

S

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

CAOA

CAOB

PKLMT

GND

VAO

VINAC

VSENSE

CSA

CSB

RT

CDR

SS

GDB

GDA

IMO

VCC

RSYNTH

VREF

DMAX

RDM

R

IMO

To CSB

To CSA

From Ixfrms

L1

UCC28070

SLUS794A – NOVEMBER 2007 – REVISED MARCH 2008

www.ti.com

Interleaving Continuous Conduction Mode PFC Controller

• High-Efficiency Server and Desktop Power

• Interleaved Average Current-Mode PWM

Supplies

Control with Inherent Current Matching

• Telecom Rectifiers

• Advanced Current Synthesizer Current

Sensing for Superior Efficiency

• Highly-Linear Multiplier Output with Internal

The

UCC28070

is

an

advanced

power

factor

Quantized Voltage Feed-Forward Correction

correction device that integrates two pulse-width

for Near-Unity PF

modulators (PWMs) operating 180

° out of phase.

• Programmable Frequency (10 kHz to 300 kHz)

This

interleaved

PWM

operation

generates

• Programmable Maximum Duty-Cycle Clamp

substantial reduction in the input and output ripple

currents, and the conducted-EMI filtering becomes

• Programmable Frequency Dithering Rate and

easier and less expensive. A significantly improved

Magnitude for Enhanced EMI Reduction

multiplier design provides a shared current reference

–

Magnitude: 3 kHz to 30 kHz

to two independent current amplifiers that ensures

–

Rate: Up to 30 kHz

matched average current mode control in both PWM

outputs while maintaining a stable, low-distortion

• External Clock Synchronization Capability

sinusoidal input line current.

• Enhanced Load and Line Transient Response

through Voltage Amplifier Output Slew-Rate

The

UCC28070

contains

multiple

innovations

including current synthesis and quantized voltage

Correction

feed-forward to promote performance enhancements

• Programmable Peak Current Limiting

in PF, efficiency, THD, and transient response.

• Bias-Supply UVLO, Over-Voltage Protection,

Features

including

frequency

dithering,

clock

Open-Loop Detection, and PFC-Enable

synchronization, and slew rate enhancement further

Monitoring

expand the potential performance enhancements.

• External PFC-Disable Interface

The UCC28070 also contains a variety of protection

• Open-Circuit Protection on VSENSE and

features

including

output

over-voltage

detection,

VINAC pins

programmable

peak-current

limit,

under-voltage

lockout, and open-loop protection.

• Programmable Soft Start

• 20-Lead TSSOP Package

Simplified Application Diagram

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 2007–2008, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.