Low voltage MOS-transistor-only precision current peak detector with signal independent discharge time constant

A low voltage precision peak detector for current signals is presented. It detects a positive peak current and holds accurately the detected current even in the presence of large negative current peaks. Peak detection of a 500 kHz signal within 3% is possible in a dynamic range of 40 dB with a 2 V supply voltage and over 60 dB with a 5 V supply voltage. Additional circuitry is also designed to achieve a signal independent and adjustable discharge time constant.