UCC1972/3
UCC2972/3
UCC3972/3
CONNECTION DIAGRAMS
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 . . . . . . . . . . . . . . . . . . 300mA
Operating Junction Temperature . . . . . . . . . . –55°C to +150°C
Storage Temperature . . . . . . . . . . . . . . . . . . . –65°C to +150°C
TSSOP-8 (TOP VIEW)
PW Package
BUCK
VBAT
COMP
FB
1
2
3
4
8
7
6
5
VDD
OUT
GND
MODE
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 500ms. Consult Pack-
aging Section of Databook for thermal limitations and consider-
ations of packages. All voltages are referenced to GND.
DIL-8 (TOP VIEW)
J, N Packages
OUT
VDD
1
8
7
6
5
GND
MODE
FB
2
3
4
BUCK
VBAT
COMP
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
VBAT Supply Current
VDD = 12V
VBAT = 25V
VBAT = 12V
VBAT = 25V
1
7
1.5
10.5
60
mA
mA
mA
mA
V
30
70
18
4
140
19
VDD Regulator Turn-on Voltage
VDD UVLO Threshold
UVLO Threshold Hysteresis
Output Section
ISOURCE = 2mA to 10mA
Low to high
17
3.6
100
4.4
300
V
200
mV
Pull Down Resistance
Pull Up Resistance
Output Clamp Voltage
Output Low
I
I
SINK = 10mA to 100mA
25
25
50
50
18
0.2
W
W
SOURCE = 10mA to 100mA
VBAT = 25V, Shunt Regulator on
MODE = 0.5V, ISINK = 1mA
CL = 1nF, Note 1
16
V
0.05
200
200
V
Rise Time
ns
ns
Fall Time
CL = 1nF, Note 1
2
TI [ TEXAS INSTRUMENTS ]
