UCC1895
UCC2895
UCC3895
SLUS157L − DECEMBER 1999 − REVISED APRIL 2008
BiCMOS ADVANCED PHASE SHIFT
PWM CONTROLLER
FEATURES
D
Programmable Output Turn-on Delay
D
Adaptive Delay Set
D
Bidirectional Oscillator Synchronization
D
Voltage-Mode, Peak Current-Mode, or
D
D
D
D
D
D
Average Current-Mode Control
Programmable Softstart/Softstop and Chip
Disable via a Single Pin
0% to 100% Duty-Cycle Control
7-MHz Error Amplifier
Operation to 1 MHz
Typical 5-mA Operating Current at 500 kHz
Very Low 150-µA Current During UVLO
DESCRIPTION
The UCC3895 is a phase-shift PWM controller
that implements control of a full-bridge power
stage by phase shifting the switching of one
half-bridge with respect to the other. It allows
constant frequency pulse-width modulation in
conjunction with resonant zero-voltage switching
to provide high efficiency at high frequencies. The
part can be used either as a voltage-mode or
current-mode controller.
While the UCC3895 maintains the functionality of
the UC3875/6/7/8 family and UC3879, it improves
on that controller family with additional features
such as enhanced control logic, adaptive delay
set, and shutdown capability. Since it is built using
the BCDMOS process, it operates with
dramatically less supply current than it’s bipolar
counterparts. The UCC3895 can operate with a
maximum clock frequency of 1 MHz.
APPLICATIONS
D
Phase-Shifted Full-Bridge Converters
D
Off-Line, Telecom, Datacom and Servers
D
Distributed Power Architecture
D
High-Density Power Modules
UCC3895
1
EAN
EAP
20
7
Q1
VOUT
2
EAOUT
SS/DISB
19
3
RAMP
OUTA
18
4
REF
OUTB
17
A
C
5
GND
PGND
16
VIN
VBIAS
6
SYNC
VCC
15
7
CT
OUTC
14
B
D
8
RT
OUTD
13
9
DELAB
CS
12
10
DELCD
ADS
11
UDG−03123
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright
2008, Texas Instruments Incorporated
www.ti.com
1
TI [ TEXAS INSTRUMENTS ]
