Rad-Tolerant, High-Speed PWM Controller



The UC1825A-DIE PWM controller is an improved version of the standard UC1825 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.


  • Rad-Tolerant: 30 kRad (Si) TID(1)
  • Compatible With Voltage-Mode or Current-Mode Control Methods
  • Practical Operation at Switching Frequencies
  • 50-ns Propagation Delay to Output
  • High-Current Dual Totem Pole Outputs
  • Trimmed Oscillator Discharge Current
  • Low 100-µA Startup Current
  • Pulse-by-Pulse Current Limiting Comparator
  • Latched Overcurrent Comparator With Full Cycle Restart

(1) Radiation tolerance is a typical value based upon initial device qualification with dose rate = 10 mrad/sec. Radiation Lot Acceptance Testing is available - contact factory for details.

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Other qualified versions of UC1825A-DIE

Version Part Number Definition
Space UC1825A-SP Radiation tolerant, ceramic packaging and qualified for use in Space-based application