title: A New Time Calibration Method for Switched-capacitor-array-based Waveform Samplers.
abstract: We have developed a new time calibration method for the DRS4 waveform sampler that enables us to precisely measure the non-uniform sampling interval inherent in the switched-capacitor cells of the DRS4. The method uses the proportionality between the differential amplitude and sampling interval of adjacent switched-capacitor cells responding to a sawtooth-shape pulse. In the experiment, a sawtooth-shape pulse with a 40 ns period generated by a Tektronix AWG7102 is fed to a DRS4 evaluation board for calibrating the sampling intervals of all 1024 cells individually. The electronic time resolution of the DRS4 evaluation board with the new time calibration is measured to be ~2.4 ps RMS by using two simultaneous Gaussian pulses with 2.35 ns full-width at half-maximum and applying a Gaussian fit. The time resolution dependencies on the time difference with the new time calibration are measured and compared to results obtained by another method. The new method could be applicable for other switched-capacitor-array technology-based waveform samplers for precise time calibration.
authors.affiliation: Department of Radiology, University of Chicago, Chicago, IL 60637.
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiology, University of Chicago, Chicago, IL 60637.
authors.forename: C-T
authors.initials: CT
authors.lastname: Chen
authors.affiliation: Department of Radiology, University of Chicago, Chicago, IL 60637.
authors.forename: N
authors.initials: N
authors.lastname: Eclov
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, IL, US 60510.
authors.forename: A
authors.initials: A
authors.lastname: Ronzhin
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, IL, US 60510.
authors.forename: P
authors.initials: P
authors.lastname: Murat
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, IL, US 60510.
authors.forename: E
authors.initials: E
authors.lastname: Ramberg
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, IL, US 60510.
authors.forename: S
authors.initials: S
authors.lastname: Los
authors.affiliation: Lawrence Berkeley National Laboratory, Berkeley, CA, US 94720.
authors.forename: W
authors.initials: W
authors.lastname: Moses
authors.affiliation: Lawrence Berkeley National Laboratory, Berkeley, CA, US 94720.
authors.forename: W-S
authors.initials: WS
authors.lastname: Choong
authors.affiliation: Department of Radiology, University of Chicago, Chicago, IL 60637.
authors.forename: C-M
authors.initials: CM
authors.lastname: Kao
keywords: Switched-Capacitors; Time Calibration; Waveform Sampling