The SG1842/43 family of control IC's provides all lockout, current limiting circuitry and start-up the necessary features to implement off-line fixed current of less than 1mA. The totem-pole output frequency, current-mode switching power supplies is optimized to drive the gate of a power with a minimum number of external components. MOSFET. The output is low in the off state to Current-mode architecture demonstrates improved provide direct interface to an N channel device. line regulation, improved load regulation, pulse- The SG1842/43 is specified for operation over by-pulse current limiting and inherent protection the full military ambient temperature range of of the power supply output switch. The bandgap 55C to 125C. The SG2842/43 is specified for reference is trimmed to 1% over temperature. the industrial range of -25C to 85C, and the Oscillator discharge current is trimmed to less SG3842/43 is designed for the commercial range than 10%. The SG1842/43 has under-voltage of 0C to 70C.