Peak detector circuit using LM393

This is the circuit diagram of a very simple and cheap peak detector circuit. This circuit operates from 5V DC and can detect signals up to 150 KHz. Dual comparator IC LM393 is the heart of this circuit. First comparator IC1a is used for detecting the peak of the input signal. Second comparator IC1b is wired as a buffer to increase the current gain.

Circuit diagram.

peak detector circuit


  • The circuit can be assembled on a Vero board.
  • The IC must be mounted on a holder.
  • Use 5V DC for powering the circuit.
  • The input AC voltage should not exceed 10V peak to peak.
  • The input sensitivity is 10mV peak to peak.