Feed-forward Output Swing Prediction AGC with Parallel-Detect Singular-Store Peak Detector

This paper presents an Automatic Gain Control (AGC) circuit with 200 to 530 μW average power consumption given a 1 V supply. The Variable Gain Amplifier (VGA) therein comes with 0.9 V input and output stages with a minimum bandwidth of 100 MHz. Feed-forward Output Swing Prediction is used to adjust the gain of the VGA corresponding to the signal envelope detected by a Parallel-Detect Singular-Store Peak Detector. With an appropriate refresh-rate control, the AGC is capable of adjusting the gain of the VGA within less than 250 ns when the input signal envelope is reduced by 20 dB, and 100 ns when raised by 20 dB. The circuit design is carried out using a 0.18 μm standard CMOS process with a core area of 0.0024 mm².