论文部分内容阅读
用常规硅二极管对低电平信号整流一直都比较麻烦。其原因是:输入信号比二极管接通电压低约0.6伏,输出便成非线性,要使其成为线性还要加1至2个运算放大器。但是,如果用一个模拟比较电路和一个双场效应晶体管开关来取代硅二极管和放大器的组合,就可以对幅度低至6毫伏、频率高至3兆赫的波形进行整流,滤波后,其输出的直流值与输入信号的幅度成正比。电路如下图所示。这种精密半波整流的原理是:输入信号加
Rectifying low level signals with conventional silicon diodes has always been troublesome. The reason is that the input signal is about 0.6 volts lower than the diode on-voltage and the output becomes non-linear, making it necessary to add 1 to 2 op amps to make it linear. However, if an analog comparator circuit and a dual field-effect transistor switch are used instead of a combination of a silicon diode and an amplifier, the waveform can be rectified as low as 6 millivolts and as high as 3 MHz. After filtering, The DC value is proportional to the amplitude of the input signal. Circuit as shown below. The principle of this precision half-wave rectification is: input signal plus