This paper presents an electronic gain control scheme which significantly increases the dynamic range of an optoelectronic receiver without deteriorating the noise properties or affecting the propagation delay or bandwidth. A current buffer with variable attenuation is placed between the photodetector and the transimpedance preamplifier. The simulated dynamic range of the proposed front-end is 80 dB. A test circuit was designed for a pulsed time-of-flight laser rangefinder to verify the feasibility of the scheme. According to measurement results, the timing point varies /spl plusmn/5 ps when the gain is varied 24 dB (1:15).
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