CMOS Peak Detector using Diode Connected MOSFET An

CMOS Peak Detector using Diode Connected MOSFET § An active type peak detector using OP-amp and transistor has high performance, however active type is too complicate structure which control and suppress the errors. § Actually many of active type peak detectors employee complicate error compensation circuit. ENC Switching Time Controller < Active Type Simple Peak Detector and Error Sources > < Example of Complicated Structure of Peak Detector > § Input error sources : Parasitic capacitance ü Input parasitic capacitance ü Coupling capacitance § MOSFET error sources ü Gate-to-drain capacitance ü Drain capacitance ü Channel charge Qch § Offset error calibrated using multiple switches § Additional control circuits and power consumption § Another error or problem generated by additional circuits § Inadequate structure for multi-channel system

CMOS Peak Detector using Diode Connected MOSFET § In a communication system, sometimes an input signal need to be rectified in order to use as the system power. § General rectifying circuit uses diodes, however, we cannot use a diode due to its forward voltage drop which cause input signal loss. § We suggest passive peak detector using diode connected MOSFET which has advantages of diode peak detector and also has active peak detector. § Our peak circuit shows only 1. 2 % loss when the amplitude of input is 1 V. On the other hands, diode peak detector has almost 50 % loss at the same condition.