Integrated optoelectronic receiver for a pulsed time-of-flight laser radar

An integrated optoelectronic receiver for a pulsed time-of-flight laser rangefinder, consisting of a pn-photodiode and a receiver, has been designed and tested. The circuit has been implemented in a 0.8 µm BiCMOS process without any process modifications. The measured bandwidth, maximum transresistance and the input reduced noise current of the amplifier channel are ∼150 MHz, 280 kΩ and 2.1 pA/√Hz. The walk error of the receiver is ±10 ps with the input signal dynamic range of 1:30 and the single-shot precision is smaller than 30 mm when the SNR is better than 10. The responsivity of the photodiode is ∼0.3 A/W at the wavelength of 850 nm, which is about half of that with commercial PIN diodes. However, the noise of the fully integrated front-end is lower and other properties can be improved because of the absence of parasitics associated with the interconnection between an external photodetector and an amplifier.