ą
D Operates With Secondary-Side PWM
Control
D Receives Isolated PWM Command Through
a Pulse-Edge-Transformer
D Initial Free-Running Soft-Start Up with
Duty-Cycle Clamping
D Up to 400-kHz Synchronizable Switching
Frequency
D High-Current FET Drive (1.
5-A Sink, 0.
75-A
Source)
D Overcurrent Protection D Under
voltage Lockout with 2-V Hysteresis D Low-Current Startup
UCC2960, UCC3960 PRIMARYĆSIDE STARTUP CONTROLLER
SLUS430A – APRIL 1999 – REVISED DECEMBER 2000
typical operating circuit
X
VIN
UCC3960
2 FB
FEED BACK
1 SS
VDD 8 REF 4
SOFT START
OUT 7
3 RT
FREQ SET
CS 5 GND 6
UDG–99010
description
Figure 1
The UCC3960 primary-side startup controller is a unique solution that provides ...