Patent ID: 8988112
Filing Date: 2015-03-24
Classification: G01R,H03K

Abstract:
1. An activity detector for a differential signal having first and second components, the activity detector comprising: a current source comprising an output transistor having a drain and configured to be coupled to a power supply line; a first transistor having a drain coupled to said current source, a source defining a first input terminal configured to receive the first component of the differential signal, and a gate; a second transistor having a drain coupled to said current source, a source defining a second input terminal configured to receive the second component of the differential signal, and a gate; a bias circuit configured to apply a voltage to the gates of said first and second transistors to establish a balance condition wherein current from said current source is distributed between said first and second transistors when a voltage of the first and second input terminals is equal to a threshold value, said bias circuit comprising an activity indication terminal coupled to the drains of said first and second transistors.