Single Supply Absolute Value Amplifier

This absolute value amplifier has a gain of 0.5V/V and has an input range of within a few mV of -5V to +5V. A buffer amplifier should be used on the output to prevent loading. For a faster amplifier, use an OPA354.

The rail- to- rail input and output characteristics of these CMOS op amps allow them to swing very close to their supply rails– +5V and ground. By using both an inverting and noninverting amplifier to swing only positive (due to their not being capable of swinging below ground) , each op amp acts like a perfect rectifier. Summing their outputs together in R3 & R4 combines them into an absolute value of the amplifier’s input voltage. (Circuit created by Neil P. Albaugh, TI-Tucson)

absolute value amplifier

The great feature of TINA that you can analyze this circuit immediately with TINACloud the online version of TINA. Click the link below to invoke TINACloud and analyze the circuit.

You can send this link to any TINACloud customer an they can immediatelly load by a single click and then run using TINACloud.

Michael Koltai