PVT tolerant differential circuit

摘要

An automatically calibrated differential amplifier including: an input stage differential amplifier configured to receive a input differential signal, to differentially amplify the input differential signal to generate an input stage output differential signal, and to have an input stage bias current; and a replica stage differential amplifier configured to automatically calibrate the input stage bias current in response to process or environmental variations. The differential amplifier may be included, for example, in a comparator and a multilevel receiver.

主权项

1. An automatically calibrated differential amplifier comprising:
an input stage differential amplifier configured to receive an input differential signal, to differentially amplify the input differential signal to generate an input stage output differential signal, and to have an input stage bias current; and a replica stage differential amplifier configured to automatically calibrate the input stage bias current in response to process or environmental variations and to have a replica stage bias current, the replica stage differential amplifier comprising a feedback circuit configured to receive an output of the replica stage differential amplifier and to adjust the replica stage bias current according to the output of the replica stage differential amplifier, wherein the input stage differential amplifier comprises a plurality of differential amplifier pairs that are coupled to each other at their inputs to receive the input differential signal.