Maxim 公司的MAX3806是高增益線性前置放大器,主要用於(yu) 激光測距. MAX3806工作電壓5V,能把光電二極管交流耦合的電流轉換成單端電壓信號,線性範圍高達40uAP,過載電流高達2mAP,5.0V時的功耗為(wei) 50mW,可選擇增益為(wei) 60K或30K,可選擇衰減為(wei) 14dB,主要用於(yu) 汽車中的LIDAR傳(chuan) 感器,手提測距的激光傳(chuan) 感器,測試測量和工業(ye) 控製的激光傳(chuan) 感器.本文介紹了MAX3806的主要特性,功能方框圖以及典型應用電路.

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

                圖1.MAX3806功能方框圖

                 
                  圖2.MAX3806典型應用電路

                    
                      圖3.MAX3806典型應用電路(續)