UC2851
FEATURES
- All Control, Driving, Monitoring, and Protection
Functions Included
- Low-Current Off Line Start Circuit
- Voltage Feed Forward or Current Mode Control
- High Current Totem Pole Output
- 50% Absolute Max Duty Cycle
- PWM Latch for Single Pulse Per Period
- Pulse-by-Pulse Current Limiting plus Shutdown for Over-Current Fault
- No Start-Up or Shutdown Transients
- Slow Turn-On Both Initially and After Fault
Shutdown
- Shutdown Upon Over or Under Voltage Sensing
- Latch Off or Continuous Retry After Fault
- 1% Reference Accuracy
- 500k Hz Operation
- 18 Pin DIL or 20 Pin PLCC Package
BLOCK DIAGRAM
DESCRIPTION
The UC1851 family of PWM controllers are optimized for offline primary side control. These devices include a high current totem pole output stage and a toggle flip-flop for absolute 50% duty cycle limiting. In all other respects this line of controllers is pin for pin patible with the UC1841 series. Inclusion of all major housekeeping functions in these high performance...
