VCA821,pdf(Ultra-Wideband, &gt

The VCA821 is a dc-coupled, wideband, linear in dB, conTInuously variable, voltage-controlled gain amplifier. It provides a differenTIal input to single-ended conversion with a high-impedance gain control input used to vary the gain down 40dB from the nominal maximum gain set by the gain resistor (R_G) and feedback resistor (R_F).

The VCA821 internal architecture consists of two input buffers and an output current feedback amplifier stage integrated with a mulTIplier core to provide a complete variable gain amplifier (VGA) system that does not require external buffering. The maximum gain is set externally with two resistors, providing flexibility in designs. The maximum gain is intended to be set between 6dB and 32dB.