Wide dynamic range CMOS receivers for a pulsed time-of-flight laser range finder

Abstract

Two integrated CMOS 0.18 /spl mu/m receiver channels, with wide dynamic range, for a pulsed time-of-flight laser range finder were designed. The circuits use a timing discriminator based on a high-pass CR-filter at the input of the receiver to produce a bipolar pulse from a unipolar one. This pulse has a zero-crossing point that is amplitude independent and thus a wide dynamic range can be achieved by detecting it. Two different structures for the front-end have been presented. The simulated bandwidths and transimpedances are 370 MHz, 280 MHz and 3.4 M/spl Omega/, 5 M/spl Omega/. The simulated walk error is under 100 ps over a 1:1000 dynamic range for typical process parameters in both channels.