【摘要】 自动增益控制电路(AGC),广泛应用于无线通信、工业自动化及医疗设备等。它根据输入信号幅度波动进行增益切换,使输出信号幅度维持稳定。目前AGC环路多采用输出信号峰值检测、AD采集、比较器和环路滤波器产生控制信号,控制可变电压增益放大器(VGA)增益,电路设计复杂,成本高。本文设计一款基于MC34063负反馈支路的自动增益控制电路,该电路由AD603放大器、精密整流峰值检测器、运算电路和MC34063电路组成,创新利用电源芯片产生VGA增益控制电压,该方法可替代传统的负反馈支路环节,电路简单,成本低,响应速度较快。更多还原

【Abstract】 Automatic gain control circuit(AGC)is widely used in wireless communication,industrial automation and medical equipment.It gains switching according to the amplitude fluctuation of input signal,so that the amplitude of output signal remains stable.At present,the AGC loop uses the output signal peak detection,the AD acquisition,the comparator and the loop filter to produce the control signals,and controls the gain of the variable voltage gain amplifier(VGA).The circuit design is complex and the cost is high.In this paper,an automatic gain control circuit based on MC34063 negative feedback branch was designed.The circuit consisted of AD603 amplifier,precision rectification peak detector,operation circuit and MC34063 circuit.The power chip produced VGA gain control voltage.This method can replace the traditional negative feedback branch link.The circuit is simple and has low cost,the response speed is faster.更多还原