摘要
在数字信号采集系统中,A/D转换器对输入的模拟信号电压有一定的限制。为使输入信号不受这一限制,设计了一种数字式自动增益放大电路,该电路采用数字电位器取代放大器的反馈电阻,单片机根据放大器输出电压自动调整数字电位器的阻值来调节放大器增益,使输出电压始终维持在所设定的上下限电压之间。在实验室做了性能测试实验,结果表明:设计的自动增益放大电路性能稳定可靠,输出电压能够满足A/D转换器件的电压转换要求。
In the system of signal acquisition, the A/D converter confined the input value of analog signal voltage. A digital AGC circuit using a digital potentiometer to replace the feedback resistance of the amplifier was designed. In order to get an appropriate gain, MCU adjusted the resistance of the digital potentiometer automatically according to the voltage value of amplifier＇s output. This system was tested faithfully in the laboratory. The experimental results show that the AGC circuit is reliable and meets the requirement of A/D converter.
出处
《仪表技术与传感器》
CSCD
北大核心
2008年第8期75-77,80,共4页
Instrument Technique and Sensor
基金
国家"十一五"科技攻关项目(2006BAK02B01-09)
