2

UCC1972/3

UCC2972/3

UCC3972/3

TSSOP-8 (TOP VIEW)

PW Package

ABSOLUTE MAXIMUM RATINGS

VBAT ......................................... +27V

VDD Maximum Forced Current .................... 30mA

Maximum Forced Voltage ..........................17V

BUCK .................................. –5V to VBAT

MODE ................................. –0.3V to 4.0V

MODE Maximum Forced Current ..................300

mA

Operating Junction Temperature .......... –55°C to +150°C

Storage Temperature ................... –65°C to +150°C

Unless otherwise indicated, currents are positive into, negative

out of the specified terminal. Pulse is defined as less than 10%

duty cycle with a maximum duration of 500

ms. Consult Pack-

aging Section of Databook for thermal limitations and consider-

ations of packages. All voltages are referenced to GND.

GND

OUT

VDD

MODE

VBAT

BUCK

COMP

FB

1

2

3

4

8

7

6

5

CONNECTION DIAGRAMS

ELECTRICAL CHARACTERISTICS:Unless otherwise specified these specifications hold for TA=0°C to +70°C for the

UC3972/3, –40°C to +85°C for the UC2972/3, and –55°C to +125°C for the UC1972/3; TA=TJ; VDD=VBAT=VBUCK=12V;

MODE=OPEN. For any tests with VBAT>17V, place a 1k resistor from VBAT to VDD.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

Input supply

VDD Supply Current

VDD = 12V

1

1.5

mA

VBAT = 25V

7

10.5

mA

VBAT Supply Current

VBAT = 12V

30

60

mA

VBAT = 25V

70

140

mA

VDD Regulator Turn-on Voltage

ISOURCE = 2mA to 10mA

17

18

19

V

VDD UVLO Threshold

Low to high

3.6

4

4.4

V

UVLO Threshold Hysteresis

100

200

300

mV

Output Section

Pull Down Resistance

ISINK = 10mA to 100mA

25

50

W

Pull Up Resistance

ISOURCE = 10mA to 100mA

25

50

W

Output Clamp Voltage

VBAT = 25V, Shunt Regulator on

16

18

V

Output Low

MODE = 0.5V, ISINK = 1mA

0.05

0.2

V

Rise Time

CL = 1nF, Note 1

200

ns

Fall Time

CL = 1nF, Note 1

200

ns

FB

MODE

GND

COMP

VDD

OUT

BUCK

VBAT

1

2

3

4

8

7

6

5

DIL-8 (TOP VIEW)

J, N Packages