Patent ID: 7339402
Filing Date: 2008-03-04
Classification: H03F

Abstract:
1. Amplifier circuitry including an input stage, the input stage comprising: (a) first and second transistors, each having first, second, and third electrodes, a first one of the first and second electrodes of the first transistor being coupled to receive a first signal, and a first one of the first and second electrodes of the second transistor being coupled to receive a second signal; (b) a first separator transistor having a first current-carrying electrode coupled to the second one of the first and second electrodes of the first transistor and a second current-carrying electrode coupled to the second one of the first and second electrodes of the second transistor; (c) a control circuit having a first input coupled to the first one of the first and second electrodes of the first transistor, a second input coupled to the first one of the first and second electrodes of the second transistor, and an output coupled to a gate of the first separator transistor for controlling the first separator transistor in response to the first and second signals so as to limit a reverse bias voltage across a PN junction of one of the first and second transistors; and (d) bias current circuitry coupled to bias the first and second transistors, respectively.