MIC38C43A

MIC38C42A/43A/44A/45A Micrel, Inc. MIC38C42A/43A/44A/45A BiCMOS Current-Mode PWM Controllers General Description The MIC38C4xA are fixed frequency, high performance, current-mode PWM controllers. Micrel’s BiCMOS devices are pin compatible with 384x bipolar devices but feature several improvements. Undervoltage lockout circuitry allows the ’42 and ’44 versions to start up at 14.5V and operate down to 9V, and the ’43 and ’45 versions start at 8.4V with operation down to 7.6V. All versions operate up to 20V. When compared to bipolar 384x devices operating from a 15V supply, start-up current has been reduced to 50 µA typical and operating current has been reduced to 4.0mA typical. Decreased output rise and fall times drive larger MOSFETs, and rail-to-rail output capability increases efficiency, especially at lower supply voltages. The MIC38C4xA also features a trimmed oscillator discharge current and bandgap reference. The MIC38C4xA family is available in 8-pin SOIC and MSOP8 (MM8) package options For fast rise and fall times and higher output drive, refer to the MIC38HC4x. Features Fast 40ns output rise and 30ns output fall times –40°C to +85°C temperature range meets UC284x specifications High-performance, low-power BiCMOS Process Ultralow start-up current (100µA typical) Low operating current (4mA typical) CMOS outputs with rail-to-rail swing ≥ 500kHz current-mode operation Trimmed 5V bandgap reference Pin-for-pin compatible with UC3842/3843/3844/3845 T...