Unitrode UC1841
The UC1841 family of PWM controllers has been designed to increase the level of versatility while retaining all of the performance features of • Low-current, Off-line Start Circuit • Voltage Feed Forward or Current Mode Control the earlier UC1840 devices. While still optimized for highly-efficient bootstrapped 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.| Part No. | UC1841 |
|---|---|
| Datasheet | UC1841 Download |
| Manufacturer |  Unitrode |
| Description | Programmable Off-Line PWM Controller |
| Buy | Stock & Price |
FEATURES
● All Control, Driving, Monitoring, and Protection Functions IncludedDESCRIPTION
Important performance features include a● Guaranteed Duty Cycle Clamp low-current starting circuit, linear feed-forward for constant volt-second operation, and compatibility with either voltage or current mode topologies.
● PWM Latch for Single Pulse per Period In addition to start-up and normal regulating PWM functions, these de-
● Pulse-by-Pulse Current Limiting Plus vices include built in protection from over-voltage, under-voltage, and Shutdown for Over-Current Fault over-current fault conditions with the option for either latch-off or automat-
● No Start-up or Shutdown Transients
● Slow Turn-on Both Initially and After Fault Shutdown
● Shutdown Upon Over- or Under-Voltage Sensing ic restart. While pin compatible with the UC1840 in all respects except that the polarity of the External Stop has been reversed, the UC1841 offers the following improvements: 1. Fault latch reset is accomplished with slow start discharge rather than recycling the input voltage to the chip.
