Patent ID: 7812676
Filing Date: 2010-10-12
Classification: H03F

Abstract:
1. A bipolar transistor transconductance input apparatus energized by a supply voltage, the input apparatus comprising: three differential bipolar transistor transconductance stages each stage including a controllable tail current source producing a tail current, each stage having an electrically coupled input receiving an input voltage signal, the three differential bipolar transconductance stages converting the input voltage signal into an output current signal at an electrically coupled output, the transconductance stages permitting the transfer function between the input voltage signal and the output current signal to be substantially free of dead zones when the total supply voltage is about 2.7 volts or less; and control circuitry for guiding the tail currents so that when a stage is fully-on a tail current is supplied to that stage and the other two stages do not receive tail currents.