FET-based, linear voltage-controlled resistor for wide-band gain control circuit

摘要: A gain control circuit for generating a differential output signal in response to input with controlled by an employs two asymmetric field effect transistors (FETs) as linear, voltage-controlled resistor. The FETs are interconnected drain-to-source the being applied their gates so that combined channel current is substantially linear and symmetric function of voltage. includes bipolar transistors, across bases developed collectors. resistor links emitters sources emitters, pair resistors each collector source bias FET-based may be connected either between collectors or transistors. When collectors, distortion due any common mode component reduced.