The MIC3832 and MIC3833 are unique PWM controllers designed for current-fed, multiple-output or push-pull, switched-mode power supply applications. The MIC3832/3 features UVLO (undervoltage lockout) with hysteresis, soft start with a programmable time constant, cycle-by-cycle current limiting, a PWM latch to prevent multiple outputs due to noise or ringing, and front-edge blanking. Current-fed topologies eliminate core saturation problems caused by shoot through (cross conduction) of push-pull circuits and reduce stress on the switching transistors. The MIC3832/3 has one PWM stage capable of operating up to 500kHz and two output stages, Q and Q, that operate at one-half of the system frequency at a fixed 50% duty cycle. The MIC3832 UVLO circuit permits startup when the supply is above 15.9V and forces shutdown when the supply drops below 9.8V. The MIC3833 starts up above 8.3V and shuts down below 7.8V. An internal 22V zener diode provides low power overvoltage protection. |