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(6)

Gain is defined as

ACS +

DVCOM

DVCS

, 0 V v VCS v 900 mV

Electrical Characteristics

UCC28C4x-EP

BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS

SGLS352B – DECEMBER 2006 – REVISED MAY 2007

V

DD = 15 V

(1), R

T = 10 kΩ, CT = 3.3 nF, CVDD = 0.1 µF and no load on the outputs, TA = TJ = –55°C to 125°C for the

UCC28C4x

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

Reference

Output voltage, initial accuracy

TA = 25°C , IOUT = 1 mA

4.9

5

5.1

V

Line regulation

VDD = 12 V to 18 V

0.2

20

mV

Load regulation

1 mA to 20 mA

3

25

mV

Temperature stability

(2)

0.2

0.4

mV/

°C

Total output variation

(2)

4.82

5.18

V

Output noise voltage

10 Hz to 10 kHz, TA = 25°C

50

µV

Long term stability

1000 hours, TA = 125°C(2)

5

25

mV

Output short circuit

–30

–45

–55

mA

Oscillator

TA = 25°C(3)

50.5

53

55

kHz

Initial accuracy

TA = Full Range(3)

50.5

57

KHz

Voltage stability

VDD = 12 V to 18 V

0.2

2.85

%

Temperature stability

TMIN to TMAX(2)

1

2.5

%

Amplitude

RT/CT pin peak to peak

1.9

V

TA = 25°C, RT/CT = 2 V(4)

7.7

8.4

9

mA

Discharge current

RT/CT = 2 V(4)

7.2

8.4

9.5

mA

Error Amplifier

Feedback input voltage, initial accuracy

VCOMP = 2.5 V, TA = 25°C

2.475

2.500

2.525

V

Feedback input voltage, total variation

VCOMP = 2.5 V

2.45

2.50

2.55

V

Input bias current

–0.1

–2

µA

AVOL

Open-loop voltage gain

VOUT = 2 V to 4 V

65

90

dB

Unity gain bandwidth

1.5

MHz

PSRR

Power-supply rejection ratio

VDD = 12 V to 18 V

60

dB

Output sink current

VFB = 2.7 V, VCOMP = 1.1 V

2

14

mA

Output source current

VFB = 2.3 V, VCOMP = 5 V

–0.5

–1

mA

VOH

High-level output voltage

VFB = 2.3 V, RLOAD = 15 k to GND

5

6.8

V

VOL

Low-level output voltage

VFB = 2.7 V, RLOAD = 15 k to VREF

0.1

1.1

V

Current Sense

TA = 25°C (5)(6)

2.85

3

3.15

V/V

Gain

TA = Full Range (5)(6)

2.825

3.15

V/V

Maximum input signal

VFB < 2.4 V

0.9

1

1.1

V

PSRR

Power-supply rejection ratio

VDD = 12 V to 18 V(2)(5)

70

dB

Input bias current

–0.1

–2

µA

CS to output delay

35

70

ns

COMP to CS offset

VCS = 0 V

1.15

V

Output

VOUT low (RDS(on) pull-down)

ISINK = 200 mA

5.5

15

Ω

VOUT high (RDS(on) pull-up)

ISOURCE = 200 mA

10

25

Ω

(1)

Adjust VDD above the start threshold before setting at 15 V.

(2)

Not production tested.

(3)

Output frequencies of the UCC28C41, UCC28C44, and UCC28C45 are one-half the oscillator frequency.

(4)

Oscillator discharge current is measured with RT = 10 kΩ to VREF.

(5)

Parameter measured at trip point of latch with VFB = 0 V.

4

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