| 摘要 |
An adjustable gain amplifier system having cleanly adjustable and stable linearized gain is provided for amplifying an input signal. The system generally comprises a main amplifier and a linearized transconductance amplifier coupled thereto, which generates an amplified current signal in response to the input signal according to a variably defined transconductance factor. The linearized transconductance amplifier includes a linearized transconductance portion and a translinear current amplifier portion coupled thereto. The linearized transconductance portion generates an intermediate current signal based upon a voltage of the input signal, and forms an unswitched resistor-based conduction path for that intermediate current signal. The translinear current amplifier portion forms a translinear loop section for amplifying the intermediate current signal to generate the amplified current signal. The translinear current amplifier portion is selectively reconfigurable to correspondingly adjust the transconductance factor, wherein the linearized gain is adjustably defined according to the adjusted transconductance factor. |
