Typical Operating Circuits

The MAX3806 is a high-gain linear preamplifier for distance measurement applications using a laser beam.

The device operates from a single +5.0V supply and converts current from an AC-coupled photodiode into a single-ended voltage signal. The input accepts single pulses or bursts of pulses with widths down to 30ns. The amplifier remains linear with input amplitudes from 42nAP (SNR = 3) to 40µAP. It can also withstand overload signals as large as 2mAP. The output stage is designed to drive a high-impedance load to deliver the output-voltage swing at the lowest possible power dissipation. The gain of the preamplifier stage is selected using the GAIN pin to be 60kΩ or 30kΩ. There is also an internal 14dB attenuator that is selected using the ATT pin. The output stage can be disabled (high impedance).

The device is available in a 3mm x 3mm, 12-pin TQFN package and operates over the -40°C to +105°C temperature range.