US 2010/0073033 A1 · PEAK DETECTOR

Abstract

A peak detector capable of rapidly detecting a peak value of a signal is provided. The peak detector includes first and second operational amplifiers and an auxiliary current source to detect two rail to rail signals. The first operational amplifier outputs a detection signal by buffering a first rail to rail input signal. The second operational amplifier outputs a control signal in response to a second rail to rail input signal and the detection signal. The auxiliary current source includes a terminal connected to an output terminal of the first operational amplifier and the other terminal connected to the first or second source voltage. The auxiliary current source operates in response to the control signal. The auxiliary current source supplies a current from the first source voltage to the output terminal in response to the control signal or supplies a path for discharging a current from the output terminal to the second source voltage.

Claims16

Dependent claims

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;
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.

2 more elements

A positive peak detector for detecting a positive peak of two rail to rail signals, the positive peak detector comprising:

a first operational amplifier including a positive input terminal applied with a first rail to rail input signal, a negative input terminal, and an output terminal connected to the negative input terminal;
a second operational amplifier including a negative input terminal applied with a second rail to rail input signal and a positive input terminal connected to an output terminal of the first operational amplifier;
and
an auxiliary current source including a terminal connected to the first source voltage and the other terminal connected to the output terminal of the first operational amplifier, which is controlled by a voltage value of an output terminal of the second operational amplifier.

1 more element

A negative peak detector for detecting a negative peak of two rail to rail signals, the negative peak detector comprising:

a first operational amplifier including a negative input terminal applied with a second rail to rail input signal, which outputs a control signal;
a second operational amplifier including a positive input terminal applied with a first rail to rail input signal, an output terminal, and a negative input terminal commonly connected to the output terminal and a positive input terminal of the first operational amplifier to output a detection signal;
and
an auxiliary current source including a terminal connected to the output terminal of the second operational amplifier and the other terminal connected to a second source voltage, which is controlled by the control signal.

1 more element

Dependencies are inferred from the claim text.

Peak detector

Life of this patent

Peak detector

Life of this patent

Abstract

Claims16