UCC2817, UCC2818, UCC3817, UCC3818

BiCMOS POWER FACTOR PREREGULATOR

SLUS395J - FEBRUARY 2000 - REVISED MARCH 2009

1

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Power Factor

description

The UCCx817/18 family provides all the functions necessary for active power factor corrected preregulators.

The controller achieves near unity power factor by shaping the ac input line current waveform to correspond

to that of the ac input line voltage. Average current mode control maintains stable, low distortion sinusoidal line

current.

Designed in Texas Instrument’s BiCMOS process, the UCC2817/UCC2818 offers new features such as lower

start-up current, lower power dissipation, overvoltage protection, a shunt UVLO detect circuitry, a leading-edge

modulation technique to reduce ripple current in the bulk capacitor and an improved, low-offset (

±2 mV) current

amplifier to reduce distortion at light load conditions.

block diagram

UDG-98182

VREF

9

2

16

1

15

10

5

4

DRVOUT

GND

CAI

VCC

OVP/EN

VAOUT

1.9 V

PKLMT

7.5 V

REFERENCE

UVLO

16 V/10 V (UCC2817)

10.5 V/10 V (UCC2818)

VCC

3

OSCILLATOR

12

RT

14

CT

SQ

R

PWM

LATCH

+

−

PWM

CAOUT

+

−

+

−

+

−

SS

VOLTAGE

ERROR AMP

8.0 V

13

7

11

VSENSE

VFF

8

IAC

6

MOUT

MIRROR

2:1

X2

+

−

7.5 V

ENABLE

OVP

÷

X

X

MULT

OSC

CLK

CLK

CURRENT

AMP

16 V (FOR UCC2817 ONLY)

+

−

0.33 V

ZERO POWER

R

+

−

Copyright

 2006 − 2009, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

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.

D, DW, N, and PW PACKAGES

(TOP VIEW)

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

GND

PKLMT

CAOUT

CAI

MOUT

IAC

VAOUT

VFF

DRVOUT

VCC

CT

SS

RT

VSENSE

OVP/EN

VREF