Patent ID: 7759983
Filing Date: 2010-07-20
Classification: G01R

Abstract:
1. A device for comparing the peak value of at least one voltage signal with a reference voltage, the device comprising: a reference transconductor element for converting said reference voltage into a reference current; at least one respective transconductor element for converting said at least one voltage signal into at least one respective current signal; a current-comparison node for comparing said at least one respective current signal with said reference current, generating a comparison current as a difference between said at least one respective current signal and said reference current; a current rectifier supplied with said comparison current; and a hold capacitor, charged with the output current of said current rectifier, the voltage across said capacitor indicating the outcome of the comparison between said peak value of at least one voltage signal and said reference voltage, wherein said current-comparison node and said current rectifier are obtained via a differential stage, supplied to the inputs of which are said voltage signal and said reference voltage, and wherein said differential stage comprises: a first pair of transistors biased by a first current source independent of the current signal cascaded between a supply voltage and ground and traversed by a first current, with said at least one voltage signal applied to the point of connection between the transistors of said first pair; and a second pair of transistors biased by a second current source independent of the current signal cascaded between a supply voltage and ground and traversed by a second current, with said reference voltage applied to the point of connection between the transistors of said second pair, wherein the transistors of said first pair have their control terminal short-circuited with their current-inflow terminal.