A Low-complexity FPGA TDC based on a DSP Delay Line and a Wave Union Launcher

High-precision time-to-digital converters (TDCs) are key components for controlling quantum systems and FPGAs have gained popularity for this task thanks to their low-cost and flexibility compared with Application Specific Integrated Circuits (ASICs). This paper investigates a novel FPGA-based TDC architecture that combines a wave union launcher and delay lines constructed with DSP blocks. The configuration achieves a 8.07ps RMS resolution on a low-cost Zynq FPGA with a power usage of only 0.628W. The low power consumption is achieved thanks to a combination of operating frequency and logic resource usage that are lower than other methods, such as multi-chain DSP based TDCs and multi-chain CARRY4 based TDCs.