An ultra-high timing resolution pulse generator with spur suppression and correction of errors based on real-time computation

Abstract

In this paper, a novel ultra-high timing resolution pulse generator is proposed. It is based on the waveform real-time computation method. Through real-time computing and filtering of the waveform samples, a pulse with a 0.1 ps timing resolution pulse could be generated at a 2.5 GSPS sampling rate. Based on the waveform real-time computation method, jitters are injected into the waveform time parameter to break the harmonic components caused by non-integer multiples of the sampling rate and waveform frequency. Waveform spurs are further suppressed using this approach. The pulse error correction is achieved by designing digital filters that complement the waveform distortion features. The complementary digital filters are then combined as Farrow filter coefficients by polynomial fitting. Based on the real-time computation method, pulse width modulation, frequency modulation, and amplitude modulation are easy to realize. The implemented pulse generator has four channels, whose minimum pulse width, edge time, frequency range, and amplitude range are 4, 2.5 ns, 1 μHz–120 MHz, and 50 mVpp–5 Vpp, respectively. All timing resolution and timing accuracy of pulse width, edge time, pulse period, and channel delay are 0.1 and 50 ps, respectively. Timing parameters can be changed continuously without glitches.