Microchip Technology, Inc. Current Mode PWMs Isolated Switching Regulators Off-line, 8V UVLO - 55°C to125°C SG1843Y

The SG1842/43 family of control IC's provides all the necessary features to implement off-line fixed frequency, current-mode switching power supplies with a minimum number of external components. Current-mode architecture demonstrates improved line regulation, improved load regulation, pulse-by-pulse current limiting and inherent protection of the power supply output switch. The band-gap reference is trimmed to ±1% over temperature. Oscillator discharge current is trimmed to less than ±10%. The SG1842/43 has under-voltage lockout, current limiting circuitry and start-up current of less than 1mA. The totem-pole output is optimized to drive the gate of a power MOSFET. The output is low in the off state to provide direct interface to an N-channel device. The SG1842/43 is specified for operation over the full military ambient temperature range of -55°C to 125°C. The SG2842/43 is specified for the industrial range of -25°C to 85°C, and the SG3842/43 is designed for the commercial range of 0°C to 70°C. Additional Features Optimized For Off-Line Control Low Start-Up Current (<1mA) Automatic Feed Forward Compensation Trimmed Oscillator Discharge Current Pulse-By-Pulse Current Limiting Enhanced Load Response Characteristics - Double-Pulse Suppression High-Current Totem-Pole Output (1A Peak) Internally Trimmed Band-gap Reference 500kHz Operation Under-voltage Lockout: SG1843 - 8.4 volts Low Shoot-Through Current <75mA Over Temperature