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在测量电路中,往往需要对一些微弱的信号进行采集放大,以便于对其进行分析计算,为了得到精度较高、动态范围较大的放大电路,本系统采用程控高增益放大器,并以按指数衰减正弦波信号源作为系统测试输入信号。程控高增益放大器由固定增益放大器和以DAC7541为核心构成的程控放大器两部分组成;程控选频网络以状态变量滤波器为核心,以DAC7800内部权电阻网络作为可调电阻实现中心频率精确控制。系统以MSP430单片机为控制核心,工作稳定可靠、具有较高的性能指标。
In the measurement circuit, it is often necessary to collect some of the faint signal amplification, in order to facilitate its analysis and calculation, in order to get higher accuracy, larger dynamic range of the amplifier circuit, the system uses programmable high gain amplifier, and the index Decay sine wave signal source as system test input signal. Programmable high-gain amplifier consists of fixed-gain amplifier and DAC7541 as the core of the program-controlled amplifier composed of two parts; program-controlled frequency-selective network to the state variable filter as the core to DAC7800 internal resistance network as adjustable resistor to achieve precise control of the center frequency. System to MSP430 microcontroller as the control center, stable and reliable, with high performance indicators.