UC1861-1868
UC2861-2868
UC3861-3868
DESCRIPTION (cont.)
UVLO thresholds for the UC1861/62/65/66 are 16.5V start delay, and the internal system reference.
(ON) and 10.5V (OFF), whereas the UC1863/64/67/68
Each device features dual 1 Amp peak totem pole output
drivers for direct interface to power MOSFETS. The out-
puts are programmed to alternate in the
UC1861/63/65/67 devices. The UC1862/64/66/68 out-
puts operate in unison alllowing a 2 Amp peak current.
thresholds are 8V (ON) and 7V (OFF). After V
ex-
CC
ceeds the UVLO threshold, a 5V generator is enabled
which provides bias for the internal circuits and up to
10mA for external usage.
A Fault comparator serves to detect fault conditions and
set a latch while forcing the output drivers low. The Soft-
Ref pin serves three functions: providing soft start, re-
CONNNECTION DIAGRAMS
ABSOLUTE MAXIMUM RATINGS
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22V
Output Current
Source or Sink (Pins 11 & 14) . . . . . . . . . . . . . . . . . . . . . 0.5A
DC Pulse (0.5µs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5A
Power Ground Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2V
Inputs (Pins 2, 3, 10, & 15) . . . . . . . . . . . . . . . . . . . . –0.4 to 7V
Error Amp Output Current . . . . . . . . . . . . . . . . . . . . . . . . 2mA
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1W
Junction Temperature (Operating). . . . . . . . . . . . . . . . . . 150°C
Lead Temperature (Soldering, 10 seconds) . . . . . . . . . . 300°C
PLCC-20 & LCC-20 (Top View)
Q & L Package
PACKAGE PIN FUNCTION
FUNCTION
Soft Ref
5V
NI
INV
E/A Out
Sig Gnd
Range
RMIN
CVCO
RC
Zero
NC
NC
A Out
Pwr Gnd
Pwr Gnd
VCC
PIN
1
2
3
4
5
6
7
±
±
8
9
All voltages are with respect to signal ground and all currents
are positive into the specified terminal. Pin numbers refer to
the J and N packages. Consult Unitrode Integrated Circuits da-
tabook for information regarding thermal specifications and
limitations of packages.
10
11
12
13
14
15
16
17
18
DIL-16, SOIC-16 (Top View)
J or N, DW Packages
B Out
2