Digital automatic calibration method for a time-interleaved ADCs system used in time-domain EMI measurement receiver

Abstract

The sampling rate of state of the art analog to digital converters (ADCs) limits the base-band frequency range of real-time time domain electromagnetic interference (TD-EMI) measurement systems to 1 GHz. In this paper, a time interleaved sampling architecture is introduced to overcome this limitation and to extend the baseband of the time-domain EMI receiver. Using three parallel time-interleaved ADC converters a TD-EMI measurement system with 3 GHz base bandwidth has been realized. The misalignment effects are studied and an automatic calibration routine is introduced. The 40 dB spurious free dynamic range required by the CISPR standards is achieved.