Controllable Power Operational Transconductance Amplifier

摘要

Controllable operational transconductance power amplifier (controllable power OTA) including an input stage receiving a differential input signal (OVin) and deriving therefrom first (i 1 ) and second (i 2 ) low power current signals being coupled to first (ccs 1 ) and second (ccs 2 ) current controlled output current sources being arranged in class B push pull configuration. To obtain an effective gain control while securing power efficiency and linearity, the overall gain of the power OTA is controlled by varying the gain or transconductance of the input stage (c 15 ) and by the use of means for bi-directionally rectifying said first (i 1 ) and second (io) low power current signals and providing in mutual alternation power amplification of said first (i 1 ) and second (i 2 ) low power current signals into first (I 01 ) and second (Io 2 ) mutually exclusive high power current output signals, which are supplied through a current summer to a current output (I 0 ) of said linear power amplifier.