The SG6203 is designed to control and drive the synchronous rectifier for the flyback converter. The synchronous signal of the primary switch is obtained by a single diode connected between the transformer secondary winding and the SG6203. Using the SG6203, no additional transformer winding is required and the circuit complexity can be minimized.

The power unit can be properly operated under discontinuous conduction mode (DCM) or continuous conduction mode (CCM). Problems such as “shoot-through” or “cross conduction” in CCM and energy-reverse from the secondary to the primary in DCM are prevented by the SG6203 design.

• Low operation current (1.7mA)
• One resistor for timing setting
• Internal automatic tracking for optimum dead time
• No reverse energy flow at light load
• Best suited for primary green-mode PWM IC
• Wide supply voltage range from 6V to 20V
• Built-in 18V Zener diode
• Optional current sensing:
  • Current shunt
  • RC network for better efficiency

Flyback converters, such as:

• Power adaptors
• Open-frame SMPS