AD8338ACPZ-R7

The AD8338ACPZ-R7 is an Variable Gain Amplifier (VGA) for applications that require a fully differential signal path, low power, low noise and a well-defined gain over frequency. While the inputs are differential, the device can also be driven with a single-ended source if required. The basic gain function is linear-in-dB and is controlled by the voltage applied to Pin GAIN. The nominal gain range can be shifted up or down via direct access to Pin INPD and Pin INMD, the current inputs of the VGA. This includes additional circuit blocks to enable input offset correction and automatic gain control (AGC). DC offset voltages are removed by the offset correction circuit, which behaves like a high-pass filter whose corner is set with an external capacitor. The function varies the gain of this to maintain a constant RMS output voltage. An externally applied voltage to Pin VAGC with respect to the voltage at Pin VREF sets the output RMS amplitude.