Maxim MAX40242 20V低输入电流低噪音双运放解决方案

Maxim公司的MAX40242是20V低输入偏置电流低噪音双运算放大器,工作电压从2.7V到20V或双电源±1.35V到 ±10V,每路仅消耗静态度电流1.2mA,最大输入偏置电流2pA,输入噪音5nV/√Hz,带宽10MHz,转换速率8V/μs,主要用在化学传感器接口,光电二极管传感器接口,医用血氧仪,工业过程与控制和精密仪器.本文介绍了MAX40242主要优势和特性,典型应用电路以及评估板MAX40242 EVK主要特性,电路图,材料清单和PCB设计图.

The MAX40242 provides a combination of high voltage,low noise, low input bias current in a dual channel andfeatures rail-to-rail at the output.

This dual amplifier operates over a wide supply voltagerange from a single 2.7V to 20V supply or split ±1.35Vto ±10V supplies and consumes only 1.2mA quiescentsupply current per channel.

The MAX40242 is a unity-gain stable amplifier with again-bandwidth product of 10MHz. The device outputsdrive up to 200pF load capacitor without any externalisolation resistor compensation.

The MAX40242 is available in 8-thin wafer-levelpackages (WLPs) and is rated for operation over the-40℃ to +125℃ automotive temperature range.

MAX40242主要优势和特性:

●● 2.7V to 20V Single Supply or ±1.35V to ±10V DualSupplies
●● 2pA (Max) Input Bias Current
●● 5nV/√Hz Input Voltage Noise
●● 10MHz Bandwidth
●● 8V/μs Slew Rate
●● Rail-to-Rail Output
●● Integrated EMI Filters
●● 1.2mA Supply Current per Amplifier
●● Tiny, 0.85mm x 1.65mm 8-WLP

MAX40242应用:

●● Chemical Sensor Interface
●● Photodiode Sensor Interface
●● Medical Pulse Oximetry
●● Industrial: Process and Control
●● Precision Instrumentation

图1.MAX40242典型应用电路

图2.MAX40242高阻抗源/传感器预放大应用电路

评估板MAX40242 EVK

The MAX40242 evaluation kit (EV kit) provides a proven design to evaluate the MAX40242 low-input bias current, low-noise operational amplifier (op amp) in an 8-pin μMAX® package. The EV kit circuit is preconfigured as noninverting amplifiers, but can be adapted to other topologies by changing a few components. The component pads accommodate 0805 packages, making them easy to solder and replace. The EV kit comes with a MAX40242ANA+ installed.

评估板MAX40242 EVK主要特性:

Accommodates Multiple Op-Amp Configurations
Rail-to-Rail Outputs
Accommodates Easy-to-Use 0805 Components
2.7V to 20V Single Supply or ±1.35V to ±10V Dual Supplies
Proven PCB Layout
Fully Assembled and Tested

图3.评估板MAX40242 EVK外形图

图4.评估板MAX40242 EVK电路图
评估板MAX40242 EVK材料清单:

图5.评估板MAX40242 EVK PCB设计图:左:元件面;右:元件面布局图

图6.评估板MAX40242 EVK PCB设计图:焊接面