V/F变换和F/V变换采用集成块LM331，LM331是美国NS公司生产的性能价格比较高的集成芯片，可用作精密频率电压转换器用。LM331采用了新的温度补偿能隙基准电路，在整个工作温度范围内和低到4.0V电源电压下都有极高的精度。同时它动态范围宽，可达100dB；线性度好，最大非线性失真小于0.01％，工作频率低到0.1Hz时尚有较好的线性；变换精度高，数字分辨率可达12位；外接电路简单，只需接入几个外部元件就可方便构成V/F或F/V等变换电路，并且容易保证转换精度-V/F conversion and F/V conversion using Manifold LM331, LM331 NS produced in the United States high performance and low cost integrated chip, can be used as precision frequency voltage converter uses. LM331 with a new temperature compensated bandgap reference circuit, the entire operating temperature range and low to 4.0V supply voltage has a very high accuracy. Also it wide dynamic range up to 100dB　linearity, maximum nonlinear distortion is less than 0.01 , the operating frequency low to 0.1Hz good linear fashion　conversion of high precision, digital resolution up to 12　external circuit is simple , just a few external components to facilitate access to constitute V/F or F/V conversion circuit, etc., and is easy to maintain the conversion accuracy