UCC28950 Datasheet, PDF (1/42 Pages) Texas Instruments – Green Phase-Shifted Full-Bridge Controller With Synchronous Rectification

UCC28950
www.ti.com
SLUSA16 – MARCH 2010
Green Phase-Shifted Full-Bridge Controller With Synchronous Rectification
Check for Samples: UCC28950
FEATURES
1
• Enhanced Wide Range Resonant Zero Voltage
Switching (ZVS) Capability
• Direct Synchronous Rectifier (SR) Control
• Light-Load Efficiency Management Including
– Burst Mode Operation
– Discontinuous Conduction Mode (DCM),
Dynamic SR On/Off Control with
Programmable Threshold
– Programmable Adaptive Delay
• Average or Peak Current Mode Control with
Programmable Slope Compensation and
Voltage Mode Control
• Closed Loop Soft Start and Enable Function
• Programmable Switching Frequency up to 1
MHz with Bi-Directional Synchronization
• (+/-3%) Cycle-by-Cycle Current Limit
Protection with Hiccup Mode Support
• 150-µA Start-Up Current
• V_DD Under Voltage Lockout
• Wide Temperature Range -40°C to 125°C
APPLICATIONS
• Phase-Shifted Full-Bridge Converters
• Server, Telecom Power Supplies
• Industrial Power Systems
• High-Density Power Architectures
• Solar Inverters, and Electric Vehicles
DESCRIPTION
The UCC28950 enhanced phase-shifted controller
builds upon Texas Instrument’s industry standard
UCCx895 phase-shifted controller family with
enhancements that offer best in class efficiency in
today’s high performance power systems. The
UCC28950 implements advanced control of the
full-bridge along with active control of the
synchronous rectifier output stage.
The primary-side signals allow programmable delays
to ensure ZVS operation over wide-load current and
input voltage range, while the load current naturally
tunes the secondary-side synchronous rectifiers
switching delays, maximizing overall system
efficiency.
UCC28950 Typical Application
+
CT
-
V_SENSE
C_REF
R1
R2
R3
C2
R6 ^R4 C3
ENABLE
C1
R5
C_SS
R_AB
R_CD
R_EF
UCC28950
1 VREF
GND 24
2 EA+
VDD 23
3 EA-
OUTA 22
4 COMP OUTB 21
5 SS/EN OUTC 20
6 DELAB OUTD 19
7 DELCD OUTE 18
8 DELEF OUTF 17
C_VDD
A
V_DD
V_DD
QA
B
A
C
D
V_DD
E
QB
B
F
V_REF
R_TMIN
R_T
R_SUM
Voltage Current
Sense
V_REF
R_DCM(hi)
9 TMIN
SYNC 16
10 RT
CS 15
11 RSUM ADEL 14
12 DCM ADELEF 13
R7
R_CS
R_DCM
SYNC
R_A(hi)
R_AEF(hi)
R_AEF
UCC27324
QE
E
R_A
V_DD
QC
C
V_DD
QD
D
UCC27324
QF
F
V_OUT
+
-
V_SENSE
1
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 the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated