Patent ID: 6566915
Filing Date: 2003-05-20
Classification: H03K

Abstract:
A differential envelope detector to provide envelope detection of a differential signal pair comprising a first input voltage signal and a second input voltage signal, the differential envelope detector comprising:a first capacitor having a node at a first output voltage; a second capacitor having a node at a second output voltage; and a differential amplifier comprising a first input port to be coupled to the first input voltage signal; a second input port to be coupled to the second input voltage signal; a first output port having a first output port voltage; and a second output port having a second output port voltage; wherein the output ports are coupled to the input ports in such a way as to provide negative feedback; a first device to only source, in response to the first output port voltage, small-signal current to the first capacitor; and a second device to only sink, in response to the second output port voltage, small-signal current from the second capacitor so that the difference of the first and second output voltages is indicative of the envelope of the difference of the first and second input voltage signals.