Arbitrary Waveform Generator Based on FPGA and High-Speed DAC with Real-Time Interface

Abstract:
Abstract—This paper presents an arbitrary waveform generator (AWG) based on a 28 GS/s 6 bit digital-to-analog converter (DAC) in a 90 nm CMOS technology [1, 2] and a fieldprogrammable- gate-array (FPGA) board [3]. The sampling rate flexible DAC is bonded on a printed-circuit-board (PCB) offering a real-time interface. Using the FPGA LVDS interfaces arbitrary waveforms up to 1.12 GS/s are generated. This setup is also used to characterize the assembled DAC up to sampling rates of 400 MS/s. The measured spurious-free dynamic range (SFDR) of the DAC is above 40 dB over the whole Nyquist band for a sampling rate of 400 MS/s. FPGA-based real-time synchronization of the high-speed digital inputs is supported by the DAC. Synchronization of the DAC digital inputs is necessary when using the FPGA Rocket-IO (RIO) interfaces. The working principle of the synchronization procedure is proven by measurements allowing future arbitrary waveform generation up to 25 GS/s with the FPGA RIO interfaces and a new DAC board. Keywords - AWG; digital-to-analog-converter; FPGA, Integrated circuit measurements, Measurement techniques