Donnellan Sean, Hill Ian R, Bowden William, Hobson Richard
National Physical Laboratory, Hampton Road, Teddington TW11 0LW, United Kingdom.
Rev Sci Instrum. 2019 Apr;90(4):043101. doi: 10.1063/1.5051124.
We present a field-programmable gate array (FPGA) based control system that has been implemented to control a strontium optical lattice clock at the National Physical Laboratory, UK. Bespoke printed circuit boards have been designed and manufactured, including an 8-channel, 16-bit digital to analog converter board with a 2 μs update rate and a 4-channel direct-digital synthesis board clocked at 1 GHz. Each board includes its own FPGA with 28 digital output lines available alongside the specialized analog or radio frequency outputs. The system is scalable to a large number of control lines by stacking the individual boards in a master-slave arrangement. The timing of the digital and analog outputs is based on the FPGA clock and is thus very predictable and exhibits low jitter. A particular advantage of our hardware is its large data buffers that, when combined with a pseudoclock structure, allow complex waveforms to be created. A high reliability of the system has been demonstrated during extended atomic clock frequency comparisons.
我们展示了一种基于现场可编程门阵列（FPGA）的控制系统，该系统已在英国国家物理实验室实现，用于控制锶光晶格钟。定制印刷电路板已设计并制造完成，包括一块8通道、16位、更新速率为2微秒的数模转换器板以及一块时钟频率为1吉赫兹的4通道直接数字合成板。每块板都包含其自身带有28条数字输出线的FPGA，以及专门的模拟或射频输出。通过以主从配置堆叠各个板，该系统可扩展至大量控制线。数字和模拟输出的定时基于FPGA时钟，因此非常可预测且抖动低。我们硬件的一个特别优势在于其大数据缓冲区，当与伪时钟结构结合时，可创建复杂波形。在长时间的原子钟频率比较过程中，该系统的高可靠性已得到证明。
