SG3844DM

The SG1844/45 family of control ICs provides all the necessary features to implement off-line fixed frequency, currentmode 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 bandgap reference is trimmed to ±1% over temperature. Oscillator discharge current is trimmed to less than ±10%.
The SG1844/45 has undervoltage 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.KEY
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
• UNDER-VOLTAGE LOCKOUT WITH 6V HYSTERESIS (SG1844 only)
• DOUBLE PULSE SUPPRESSION
• HIGH-CURRENT TOTEM-POLE OUTPUT
• INTERNALLY TRIMMED BANDGAP REFERENCE
• 500kHz OPERATION
• UNDERVOLTAGE LOCKOUT SG1844 - 16 volts SG1845 - 8.4 volts
• LOW SHOOT-THROUGH CURRENT <75mA OVER TEMPERATURE