VCA824

The VCA824 from Texas Instruments is a versatile, wideband, linear-in-V/V, continuously variable voltage-controlled gain amplifier (VGA). It provides a differential input to single-ended conversion with a high-impedance gain control input. The gain can be adjusted down by more than 40 dB from the nominal maximum gain, which is set externally by gain and feedback resistors. The maximum gain is intended to be set between 2 V/V and 40 V/V.

Key electrical characteristics include a 710 MHz small-signal bandwidth at a gain of 2 V/V, and a 320 MHz bandwidth at a gain of 10 V/V with a 4-V peak-to-peak signal. It boasts a high slew rate of 2500 V/µs and excellent gain linearity, with a gain accuracy of ±0.3 dB for a 20-dB maximum gain. The device operates from ±5-V supplies and provides a high output current of ±90 mA.

The VCA824 is designed for applications requiring precise gain control. Its internal architecture integrates input buffers and an output current feedback amplifier with a multiplier core, eliminating the need for external buffering. The amplifier is available in VSSOP (10-lead) and SOIC (14-lead) surface-mount packages and operates over an industrial temperature range of -40°C to 85°C.