A low-voltage, low-power current-mode automatic gain control (AGC) for battery-powered equipment

In this paper, a current-mode automatic gain control (AGC) is presented. Due to operation in current-mode, the proposed circuit provides a wide frequency response, a low supply voltage, low power consumption and electronic controllability. Thus, it is very suitable for use in portable and battery-powered equipment such as hearing aid instrument and wireless radio device. The proposed AGC consists of current controlled exponential amplifier, current-mode precision rectifier, current-mode low pass filter and current-mode integrator. The performances of the proposed circuit are explored through HSPICE simulation program using BSIM3V3 model from MOSIS, they demonstrate good agreement to the theoretical anticipation. The proposed circuit works at /spl plusmn/1.5 V supply voltage, power consumption is merely 7.12mW.