Multiple time constant rectifier apparatus and method

摘要

A rectifier circuit produces an output which is a function of the magnitude of an input signal and has a controllable transient response. The circuit requires no rectification diodes. The voltage on a capacitor is sensed and compared with that of an input voltage. The operation of charging and discharging switches is adjusted by a control circuit to charge the capacitor if the magnitude of the input signal is greater than the capacitor voltage and to discharge the capacitor if the magnitude of the input signal is less than the capacitor voltage. The attack and release function of the rectifier is selectable by limiting the rate at which current charges/discharges the capacitor, preferably with constant current sources comprised of current mirrors. Multiple time constants are achieved by replicating the storage capacitor and charge/discharge elements configured with different time constants and then summing the resultant capacitor voltages.