可编程的，脱线， PWM控制器 Programmable, Off-Line, PWM Controller
DESCRIPON
The UC1841 family of PWM controllers has been designed to increase the level of versatility while retaining all of the performance features of the earlier UC1840 devices. While still optimized for highly-efficient boot strapped primary-side operation in forward or flyback power converters, the UC1841 is equally adept in implementing both low and high voltage input DC to DC converters. Important performance features include a low-current starting circuit, linear feed-forward for constant volt-second operation, and compatibility with either voltage or current mode topologies.
FEATURES
• All Control, Driving, Monitoring, and Protection Functions Included
• Low-current, Off-line Start Circuit
• Voltage Feed Forward or Current Mode Control
• Guaranteed Duty Cycle Clamp
• 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
• PWM Output Switch Usable to 1A Peak Current
• 1% Reference Accuracy
• 500kHz Operation