摘要
遥测系统中,位同步器输入接收机或采编器的PCM信号,幅度为0.2~10Vp-p,码率及码型可编程。因此需设计直流基线调整与AGC电路,将不同类型输入信号调整为固定的基线及幅度。设计采用速率为105MSPS的AD9246完成ADC采样,FPGA中计算幅值及直流基线,AD5312完成基线及AGC控制信号DAC输出,运放AD8047完成直流基线平移,可变增益放大器AD603完成AGC调整,实现将不同码率码型、不同直流偏置及幅度的信号调整为1Vp-p,满足位同步采样要求。
In Telemetry system, the PCM signal for bit synchronizer is from receiver or data collector. Signal amplitude is 0.2 - 10Vp-p, bit rates and code type is programmable. It needs circuits to implement DC baseline adjustment and AGC for various inputs. The AD9246 is used for 105 MSPS data sampling. In FPGA, amplitude and baseline is calculated, then control signals output through AD5312. The amplifier AD8047 shifts baseline, and VGA AD603 completes AGC. Finally, the circuit adjusts the input signal with different bit rates and code types, various dc baseline and amplitude to fixed 1Vp-p. It meets the needs of sampling for bit synchronizer.
出处
《电子测试》
2017年第2期29-30,共2页
Electronic Test