UCC2961, UCC3961
ADVANCED PRIMARY SIDE STARTUP CONTROLLER
SLUS431A 鈥?MAY 2000 鈥?REVISED DECEMBER 2000
D
Operates with Secondary鈥揝ide PWM
D
D
D
D
Control
Isolated PWM Command through a Pulse
Transformer
Initial Free-Running Soft-Startup with
Duty-Cycle Clamping
Up to 400-kHz Synchronizable Switching
Frequency
High-Current FET Drive (1.5-A Sink, 0.75-A
Source)
D
Multi-Mode Overcurrent Protection with
D
D
D
D
D
Restart, Latching, or Cycle-by-Cycle
Current Limiting
Programmable Volt-Second Clamp for
Transformer Reset
Undervoltage Lockout with 2-V Hysteresis
Low-Current Startup with Optional
Disconnect
Programmable Overvoltage and
Undervoltage Protection
8鈥損in Version Also Available (UCC3960)
typical application diagram
VIN
UCC3961
OPTIONAL
DEPLETION
MODE
SWITCH
14
UV/OV
STOP
1
UVS
START
13
VDD
OVS
12
+
鈥?/div>
REF
8
VOLT
SEC
CLAMP
VS
6
OUT
CS
4
FEED
BACK
3
SOFT START
5
FREQ
SET
7
RT
SD
SS
FB
11
9
FAULT LATCH DELAY
2
CSD
AGND PGND
10
UDG鈥?9039
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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.
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漏
2000, Texas Instruments Incorporated
POST OFFICE BOX 655303
鈥?/div>
DALLAS, TEXAS 75265
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