CURRENT CANCELING GAIN CONTROL FOR HIGH FREQUENCY WIDEBAND CROSS-COUPLED AMPLIFIERS

摘要

An embodiment of the present invention provides a configuration of a cross-coupled common-source differential amplifier stage which enables performing a gain step down (attenuation) while maintaining good step flatness over a large relative bandwidth.

主权项

1. A circuit to amplify a differential input signal, the circuit comprising:
a plurality of input stages each having cross-coupled transistors, and first and second transistors coupled as a common source differential pair to cooperate in amplifying the differential input signal; and a controller operable to apply a mode signal to the cross-coupled transistors of at least one input stage to selectively activate the at least one input stage in a first mode or to selectively deactivate the at least one input stage in a second mode; wherein gain and an attenuation provided by the at least one input stage is dependent on an applied mode signal.