General Description
The MIC4043 is a shunt regulator optimized for secondaryside regulation in low-voltage power supplies. Featuring an output stage guaranteed to swing within 400mV of ground, the MIC4043 can be used in power supplies operating down to 1.8V, even with optoisolators requiring greater than 1.2V of headroom.

Features
• Ideal for 1.8V switching converters
• Low-voltage operation
    400mV maximum saturation over
    operating temperature range
• Easy to use
    voltage in, current out
• 2% voltage tolerance over operating temperature range

Applications
• Optically isolated low-volage power supplies
• Low-voltage discrete regulator control