Patent ID: 8195119

Claim:
A switchable amplifier for use in a multi-mode device operable between a first low frequency mode of operation and a second high frequency mode of operation, the switchable amplifier comprising: a parallel input transistor pair; a core amplifier circuit, the core amplifier circuit having an input transistor pair that is permanently enabled during operation in the first low frequency and second high frequency modes of operation; and a plurality of switches coupled to the parallel input transistor pair and to the input transistor pair and configured to selectively turn on and off to set the switchable amplifier: (i) in a large input transistor pair configuration when the multi-mode device is operating in the first low frequency mode of operation, which mode is characterized by low amplifier bandwidth, and (ii) in a small transistor pair configuration when operating in the second high frequency mode of operation, which mode is characterized by high amplifier bandwidth.