前端电路 KBA-00650-4S007-320-A-LC-SIG4 实现核脉冲的模/数转换

KBA-00650 4S007-320-A LC-SIG4前端电路由单端转差分和高速ADC电路组成。差分电路由于其良好的抗共模干扰能力而应用广泛。由于 调理电路输出的脉冲信号为单极性信号，若直接送入ADC，将损失一半的动态范围。设计中在运放中加入一个适当的偏置电压，将单极性信号转换成双极性信号后 再送入ADC，以保证动态范围。将信号由单端转换成差分的同时，进行抗混叠滤波处理，完成带宽的调整 。

本设计使用AD9649 - 65 高速ADC 实现核脉冲的模/数转换，AD9649 为14 位并行输出的高速模/数转换器，具有功耗低、尺寸小、动态特性好等优点。当信号从探测器通过调理电路，过差分转单端电路后，以差分信号的形式进入ADC， 在差分时钟的控制下，转换成14 位数据，进入FPGA.该高速A/D 在外部FPGA 的控制下对信号进行采样。然后将采样后的数字信号送入FPGA 中实现数字核脉冲的幅度提取。图2 为A/D 转换的原理图，AD9649在差分时钟的同步下完成A/D转换，D0~D13为14个有效输出数据位。

KBA-00650-4S007-320-A-LC-SIG4前端电路是指燃气轮机发电机组中，位于燃气轮机与发电机之间的电路。

前端电路主要作用是控制燃机发电机组的启动、加速、减速、停机等，并对燃气轮机发电机组的转速、功率、温度、压力等参数进行监测与控制，以确保燃气轮机发电机组能够安全、可靠、经济地运行。

前端电路 KBA-00650-4S007-320-A-LC-SIG4 实现核脉冲的模/数转换

The KBA-00650 4S007-320-A LC-SIG4 front-end circuit consists of single-ended differential and high-speed ADC circuits. Differential circuits are widely used because of their good resistance to common-mode interference. Since the pulse signal output by the conditioning circuit is a unipolar signal, half of the dynamic range will be lost if it is directly fed into the ADC. In the design, an appropriate bias voltage is added to the operation amplifier to convert the unipolar signal into a bipolar signal before sending it to the ADC to ensure the dynamic range. When the signal is converted from single end to differential, anti-aliasing filtering is performed to adjust the bandwidth.

In this design, AD9649-65 high-speed ADC is used to realize the analog/digital conversion of nuclear pulse. The AD9649 is a high-speed analog/digital converter with 14-bit parallel output, which has the advantages of low power consumption, small size and good dynamic characteristics. When the signal passes through the conditioning circuit from the detector to the single-ended circuit, it enters the ADC in the form of a differential signal, is converted into 14-bit data under the control of the differential clock, and enters the FPGA. The high-speed A/D samples the signal under the control of an external FPGA. Then the sampled digital signal is sent to FPGA to realize amplitude extraction of digital core pulse. Figure 2 shows the schematic diagram of A/D conversion. The AD9649 completes A/D conversion under the synchronization of the differential clock, and D0 to D13 are 14 effective output data bits.

KBA-00650-4S007-320-A-LC-SIG4 Front-end circuit refers to the circuit between the gas turbine and the generator in the gas turbine generator set.

The main function of the front-end circuit is to control the start-up, acceleration, deceleration and shutdown of the gas turbine generator set, and to monitor and control the parameters of the gas turbine generator set, such as speed, power, temperature and pressure, so as to ensure the safe, reliable and economical operation of the gas turbine generator set.