Patent ID: 7898300
Filing Date: 2011-03-01
Classification: G01R

Abstract:
1. A peak detector for detecting a peak of two rail to rail input signals, the peak detector comprising: a first operational amplifier outputting a detection signal Vo by buffering a first rail to rail input signal, the first operational amplifier including a terminal that receives the first rail to rail input signal and the other terminal that is connected to the output terminal wherein structures of input transistors which constitute an input stage of the first operational amplifier are opposite to those of input transistors which constitute an input stage of the second operational amplifier; a second operational amplifier outputting a control signal in response to a second rail to rail input signal and the detection signal; and an auxiliary current source including a terminal connected to an output terminal of the first operational amplifier and the other terminal connected to a first source voltage or second source voltage, which operates in response to the control signal, wherein the auxiliary current source supplies a current from the first source voltage to the output terminal in response to the control signal or discharges a current from the output terminal to the second source voltage.