BUY LM311D https://www.utsource.net/itm/p/310054.html
Voltage comparator
Description: Voltage Comparator Feature: Wide Single Supply Voltage Range Low Input Bias Current Low Input Offset Voltage Output Can Sink or Source up to 20 mA Low Power Consumption High Input Impedance High Output Voltage Swing Low Output Saturation Voltage Application: Voltage Level Detection Signal Clipping Signal Limiting Pulse Generation Window Comparators Schmitt Triggers (For reference only)