UCC28950_15 Datasheet, PDF (1/74 Pages) Texas Instruments – UCC28950 Green Phase-Shifted Full-Bridge Controller With Synchronous Rectification

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UCC28950
SLUSA16C – MARCH 2010 – REVISED NOVEMBER 2015
UCC28950 Green Phase-Shifted Full-Bridge Controller With Synchronous Rectification
1 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 and Off Control with
Programmable Threshold
– Programmable Adaptive Delay
• Average or Peak Current Mode Control With
Programmable Slope Compensation and Voltage
Mode Control
• Naturally Handles Pre-Biased Start Up With DCM
Mode
• 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 Undervoltage Lockout
• Wide Temperature Range –40°C to +125°C
2 Applications
• Phase-Shifted Full-Bridge Converters
• Datacom, Telecom, and Wireless Base-Station
Power
• Server, Power Supplies
• Industrial Power Systems
• High-Density Power Architectures
• Solar Inverters, and Electric Vehicles
3 Description
The UCC28950 enhanced phase-shifted controller
builds upon Texas Instrument’s industry standard
UCx895 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.
The UCC28950 also offers multiple light-load
management features including burst mode and
dynamic SR on/off control when transitioning in and
out of Discontinuous Current Mode (DCM) operation,
ensuring ZVS operation is extended down to much
lighter loads.
In addition, the UCC28950 includes support for
current or voltage mode control. Programmable
switching frequency up to 1 MHz and a wide set of
protection features including cycle-by-cycle current
limit, UVLO and thermal shutdown. A 90-degree
phase-shifted interleaved synchronized operation can
be easily arranged between two converters.
The UCC28950 is available in TSSOP-24 package.
Device Information⁽¹⁾
PART NUMBER PACKAGE
BODY SIZE (NOM)
UCC28950
TSSOP (24)
7.80 mm x 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
+
VIN
CIN
-
VSENSE
UCC28950 Typical Application
CT
VBIAS
CREF
R1
R2
UCC28950
1 VREF
GND 24
CVDD
VDD
RLF2
2 EA+
VDD 23
R3
C2
R6 ^R4 C3
C1
R5
CSS
3 EA-
4 COMP
5 SS/EN
RAB
ENABLE
RCD
6 DELAB
7 DELCD
REF
8 DELEF
RTMIN
RT
9 TMIN
VREF
10 RT
RSUM
11 RSUM
RDCMHI
VREF
12 DCM
OUTA 22
OUTB 21
OUTC 20
OUTD 19
OUTE 18
OUTF 17
SYNC 16
CS 15
ADEL 14
ADELEF 13
DA
R7
RLF1
RCS
RDCM
CLF
A
B
A
C
D
E
F
B
SYNC
RAHI
VDD
QA
VDD
QB
RAEFHI
RAEF
UCC27324
QE
E
RA
T1
LOUT
VDD
QC
C
VDD
QD
D
UCC27324
QF
F
VOUT
+
COUT
-
VSENSE
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.