在模／数变换器的前面加一级可编程增益电路能够扩展数据采集系统的动态范围。在系统模／数变换器（ＡＤＣ）的前面加一增益为２的前置放大器可使测量分辨率增加１位，只要模／数输入不超过其范围即可。所以，一个１２位ＡＤＣ系统可扩展到１３位。二进制加权的前置放大器增益 Adding a programmable gain circuit in front of the A / D converter can extend the dynamic range of the data acquisition system. Adding a preamplifier gain of 2 to the front of the system analog-to-digital converter (ADC) increases the measurement resolution by 1 as long as the A / D input does not exceed its range. Therefore, a 12-bit ADC system can be expanded to 13 bits. Binary weighted preamplifier gain