The MIC38HC43YM is a fixed frequency current-mode PWM Controller with 1A drive current capability. Micrel's BiCMOS device is pin-compatible with 384x bipolar devices. Its high output drive, with fast rise and fall times, combined with low startup current make it an ideal PWM controller where high efficiency is required. When compared to bipolar UC384x devices operating from a 15V supply, start-up current has been reduced to 50μA typical and operating current has been reduced to 4mA typical. Decreased output rise and fall times drive larger MOSFETs and rail-to-rail output capability increases efficiency, especially at lower supply voltages. The MIC38HC4x also features a trimmed oscillator discharge current and bandgap reference.