UCC2891, UCC2892

UCC2893, UCC2894

SLUS542F − OCTOBER 2003 − REVISED JULY 2009

4

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ELECTRICAL CHARACTERISTICS

VDD = 12 V(1), 1-µF capacitor from VDD to GND, 0.01-µF capacitor from VREF to GND, RON = ROFF = 75 kΩ, RDEL = 10 kΩ,

RSLOPE = 50 kΩ, −40 °C ≤ TA = TJ ≤ 125°C (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Voltage Reference

VREF

Reference voltage

TJ = 25°C

4.85

5.00

5.15

V

VREF

Reference voltage

0 A < IREF < 5 mA,

over temperature

4.75

5.00

5.25

V

ISC

Short circuit current

REF = 0 V,

TJ = 25°C

−20

−11

−8

mA

INTERNAL SLOPE COMPENSATION

m

Slope(3)

FB = High

-10%

R

CS

R

SLOPE

+10%

OSCILLATOR

fOSC

Oscillator frequency

TJ = 25°C

237

250

263

kHz

Total variation

−40

°C < TJ 125°C; 8.5 V < 14.5 V

225

270

kHz

Total variation

−40

°C < TJ 125°C; 8.5 V < 14.5 V

225

270

kHz

VP_P

Oscillator amplitude (peak-to-peak)

2

V

SYNCHRONIZATION

VSYNCH

SYNC theshold voltage

1.6

2.3

3.0

V

tDEL

SYNC-to-output delay

50

ns

PWM

Maximum duty cycle

66%

70%

74%

Minimum duty cycle

0%

PWM offset

CS = 0 V

0.43

0.50

0.61

V

CURRENT SENSE

VLVL

Current sense level shift voltage

0.40

0.50

0.60

VERR(max) Maximum voltage error (clamped)

4.8

5.0

5.2

VCS

Current sense threshold

UCC2891

UCC2893

0.71

0.75

0.79

V

VCS

Current sense threshold

UCC2892

UCC2894

1.23

1.27

1.31

(1) Set VDD above the start threshold before setting at 12 V.

(2) Does not include current of the external oscillator network.