UCC1972/3
UCC3972/3
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
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.
CONNECTION DIAGRAMS
TSSOP-8 (TOP VIEW)
PW Package
BUCK
VBAT
COMP
FB
1
2
3
4
8
7
6
5
VDD
OUT
GND
MODE
DIL-8 (TOP VIEW)
J, N Packages
OUT
1
8
7
6
5
GND
MODE
FB
COMP
VDD 2
BUCK
VBAT
3
4
ELECTRICAL CHARACTERISTICS:
Unless otherwise specified these specifications hold for T
A
=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; T
A
=T
J
; VDD=VBAT=VBUCK=12V;
MODE=OPEN. For any tests with VBAT>17V, place a 1k resistor from VBAT to VDD.
PARAMETER
Input supply
VDD Supply Current
VBAT Supply Current
VDD Regulator Turn-on Voltage
VDD UVLO Threshold
UVLO Threshold Hysteresis
Output Section
Pull Down Resistance
Pull Up Resistance
Output Clamp Voltage
Output Low
Rise Time
Fall Time
I
SINK
= 10mA to 100mA
I
SOURCE
= 10mA to 100mA
VBAT = 25V, Shunt Regulator on
MODE = 0.5V, I
SINK
= 1mA
CL = 1nF, Note 1
CL = 1nF, Note 1
25
25
16
0.05
200
200
50
50
18
0.2
W
W
V
V
ns
ns
VDD = 12V
VBAT = 25V
VBAT = 12V
VBAT = 25V
I
SOURCE
= 2mA to 10mA
Low to high
17
3.6
100
1
7
30
70
18
4
200
1.5
10.5
60
140
19
4.4
300
mA
mA
TEST CONDITIONS
MIN
TYP
MAX
UNITS
m
A
mA
V
V
mV
2
TI [ TEXAS INSTRUMENTS ]
