The SG1844/45 family control ICs provide all the functions required to implement off-line fixed frequency, current mode switching power supplies with a minimum number of external components. The current mode architecture demonstrates improved profile, improved load regulation, pulse bypulse current limiting and inherent protection of the power output switch. Bandgap reference trim ±1% with temperature. Oscillator discharge current is trimmed to less than ±10%. The SG1844/45 have under-voltage lockout, and the current-limiting circuit startup current is less than 1mA. The totem pole output is optimized to drive the gate of a power MOSFET. Provides a direct interface to an N-channel device with the output low in the shutdown state. Both operate with a maximum duty of zero to <50% due to one cycle range internally switching the flip-flop blanking the output off all other clock cycles. The SG1844/45 is specified for an operating temperature range of -55°C to 125°C over the entire military environment. The SG2844/45 is specified for the industrial temperature range of -25°C to 85°C, and the SG3844/45 is designed for the commercial range of 0°C to 70°C.

main feature
* Offline control optimization
* Low startup current (less than 1mA)
* Automatic feedforward compensation
* Trim the discharge current of the oscillator
* Pulse by pulse current limit
* Enhanced load response characteristics
* Under voltage lockout 6V hysteresis (SG1844 only)
* Double pulse suppression
* High current totem pole output
* Internally trimmed bandgap reference
* 500kHz operation
* Under voltage lockout
SG1844 - 16 Volt
SG1845 - 8.4 Volts
* Low shoot-through current <75mA at different temperatures