UC3823B

UC1823A, UC2823A, UC2823B, UC3823A, UC3823B UC1825A, UC2825A, UC2825B, UC3825A, UC3825B SLUS334F – AUGUST 1995 – REVISED AUGUST 2022 High-Speed PWM Controller 1 Features Improved versions of the UC3823/UC3825 PWMs Compatible with voltage-mode or current-mode control methods Practical operation at switching frequencies to 1 MHz 50-ns propagation delay to output High-current dual totem pole outputs (2-A peak) Trimmed oscillator discharge current Low 100-μA startup current Pulse-by-pulse current limiting comparator Latched overcurrent comparator with full cycle restart 2 Description The UC3823A and UC3823B and the UC3825A and UC3825B family of PWM controllers are improved versions of the standard UC3823 and UC3825 family. Performance enhancements have been made to several of the circuit blocks. Error amplifier gain bandwidth product is 12 MHz, while input offset voltage is 2 mV. Current limit threshold is assured to a tolerance of 5%. Oscillator discharge current is specified at 10 mA for accurate dead time control. Frequency accuracy is improved to 6%. Startup supply current, typically 100 μA, is ideal for off-line applications. The output drivers are redesigned to actively sink current during UVLO at no expense to the startup current specification. In addition each output is capable of 2-A peak currents during transitions. Functional improvements have also been implemented in this family. The UC3825 shutdown comparator is now a high-speed overcurrent compar...