VCA610在水声模拟信号调理机中的应用

The application of VCA610 to AGC of underwater acoustic signals

在水中兵器试验中,水声模拟信号调理机输入信号的超大动态范围,决定了自动增益控制电路(AGC)不仅是其重要的组成部分之一,更是其必要和关键的设备。VCA610是TI公司研发的电压控制可变增益放大器,它不仅具有一般AGC芯片的低噪声、高阻抗、宽波段的性能特点,更具有独特的"线性增益和80dB的增益控制范围"。文章从通用水声模拟信号调理机的功能组成入手,结合VCA610的性能特点和具体使用要求,重点分析其输入/输出对应关系,提出了比较实践可行的"VCA610在水声模拟信号调理机中的AGC应用电路",实现了"输入信号范围(2mV～2V)60dB的线性、无失真、恒定输出"的战技指标。文章对VCA610的控制端的抗干扰性和输入端的消直电路也作了简要的分析和设计,以提高产品的通用性能。

In underwater ordnanac, the underwater acoustic amplifier handles an exceptionally wide range of input signal levels, by using Automatic Gain Control（AGC）, which not only is a significant part of am- plifier, but also is the necessary key equipment. The VCA610 is a wideband,continuously variable voltage controlled gain amplifier, with the features of low noise, high input impedance, and wide bandwidth. Especially It provides linear-dB gain with a control range of 80dB. Based on its features and specificatious, analyzing the VCA610＇s Input/Output relation, the VCA610 has been applied to AGC circuit of underwater acoustic signals, with a constant output for the input range of 60dB. And an offset adjustment for the control circuit of VCA610 in the amplifier is designed.