VCA824ID

The VCA824 is a DC-coupled, wideband, V/V linear, continuously variable voltage-controlled gain amplifier. The device provides a differential input for single-ended conversion with a high-impedance gain control input, used to reduce the rated maximum gain set by the gain resistor (RG) and feedback resistor (RF) by 40dB. The internal architecture of the VCA824 includes two input buffers and an output current feedback amplifier stage integrated with a multiplier core, providing a complete variable gain amplifier (VGA) system that requires no external buffering. Maximum gain can be set externally via two resistors for design flexibility. The maximum gain should be set between 2V/V and 40V/V. Under ±5V supply conditions, as the control voltage varies from 1V to -1V, the VCA824 adjusts gain in a V/V linear manner. For example, with the maximum gain set to 10V/V, the VCA824 gain control range spans from 10V/V (at 1V input) to 0.1V/V (at -1V input). The VCA824 features excellent gain linearity. With maximum gain set to 20dB and the gain control input voltage varying between 0V and 1V, gain deviation does not exceed ±0.3dB (maximum at 25°C).

Applications

• Differential line receiver
• Differential equalizer
• Pulse amplitude compensation
• Variable attenuator
• Voltage-controlled active filter

Key features

• 710MHz small-signal bandwidth (G = 2V/V)
• 320MHz, 4VP-P bandwidth (G = 10V/V)
• 0.1dB gain flatness to 135MHz
• 2500V/μs slew rate
• Gain adjustment range greater than 40dB
• High gain accuracy: 20dB ±0.3dB
• High output current: ±90mA