Mixed-signal full-wave precision rectifier

An apparatus comprising a full-wave precision rectifier circuit having an input and an output, the circuit comprising:

• a comparator having two comparator inputs and a comparator output indicating a difference in voltage between the two inputs, one of the inputs being coupled to the rectifier circuit input;
• an analog switch with a control input coupled to the comparator output, a first input coupled to an analog electrical input and a second input coupled to a reference input, the switch configured to select one of an input signal or a reference signal to output as a switch output;
• and
• an amplifier coupled to receive the switch output and to generate a signal following the rectifier circuit input at an output of the amplifier.

A method comprising:

• generating a digital signal indicating which of voltage of an input signal and a reference voltage are greater;
• providing the digital signal to a control input of an analog selector, the analog selector being configured to select and output one of a plurality of signals as an analog selector output signal;
• and
• providing an amplifier coupled to the analog selector output, the amplifier being configured to generate an electrical signal following the input signal in an inverting or non-inverting manner based on the selected analog selector output.