基于开关电容阵列ASIC芯片的多通道波形数字化系统设计

基于开关电容阵列（SCA）技术可以实现超高速的波形数字化。本研究是基于实验室设计完成的FEL_SCA芯片进行8通道2 Gsps的波形数字化模块的设计,电路的配置和读出控制功能集成在单个FPGA中完成,此外该模块还包含SDRAM缓存及USB接口。目前已在实验室环境下对其进行了直流电压测试、瞬态波形测试和带宽测试,测试结果表明,在FEL_SCA芯片的输入动态范围100 mV~1 V之间,本波形数字化模块的INL好于1%,通道的RMS噪声约为1.76 mV,带宽约为450 MHz,达到设计目标。Switched Capacitor Arrays (SCAs) can be employed to achieve high speed waveform digitization. In this paper, we designed an 8-channel 2 Gsps waveform digitization module using four SCA chips named FEL_SCA which was designed in our laboratory. In this module, we used a FPGA device for data readout and circuit configuration. Besides, a 128 Mb SDRAM and USB interface were integrated in this module. We have also conducted DC voltage tests, transient tests and bandwidth tests on this module. The results indicate that in the signal voltage range 100 mV~1 V, the INL is better than 1%, the RMS noise is about 1.76 mV and the -3 dB input bandwidth is 450 MHz.