Maxim 公司的MAX3806是高增益线性前置放大器,主要用于激光测距. MAX3806工作电压5V,能把光电二极管交流耦合的电流转换成单端电压信号,线性范围高达40uAP,过载电流高达2mAP,5.0V时的功耗为50mW,可选择增益为60K或30K,可选择衰减为14dB,主要用于汽车中的LIDAR传感器,手提测距的激光传感器,测试测量和工业控制的激光传感器.本文介绍了MAX3806的主要特性,功能方框图以及典型应用电路.

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 60kor 30k. 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.

MAX3806主要特性:
♦ +5V Supply Voltage
♦ Linearity Range Up to 40μAP
♦ Overload Current Up to 2mAP
♦ 50mW Power Dissipation at +5.0V
♦ 1.5pA/√Hz Noise Density at 60kGain
♦ 14nARMS Input-Referred Noise at 60kGain
♦ Selectable Gains (60k, 30k)
♦ Selectable 14dB Attenuation

MAX3806应用:
LIDAR Sensors for Automotive Applications (ACC, Stop&Go)
Laser Sensors for Portable Distance
Measurement
Laser Sensors for Industrial Applications

                图1.MAX3806功能方框图

                 
                  图2.MAX3806典型应用电路

                    
                      图3.MAX3806典型应用电路(续)