MAX40056主要特性以及应用电路

Maxim公司的MAX40056是具有输入共模拟抑制范围-0.1V到+65V的双向电流放大器（CSA），非常适合电感负载如马达和螺线管，其PWM是用来控制驱动电压和电流，从500V/μs PWM边沿，具有快速的2μs PWM 边沿恢复（1%），共模抑制比（CMRR）典型为60dB （50V， ±500V/μs输入）和140dB DC.工作电压+2.7V到 +5.5V，工作温度-40℃ 到 +125℃，主要用在PWM H桥马达电流检测，螺线管电流检测，电感负载电流检测，电池堆栈监视器和汽车电子。本文介绍了MAX40056主要优势和特性，框图，应用电路，以及评估板MAX40056 EVK主要特性，电路图，材料清单和PCB设计图。

The MAX40056 is a bidirectional current-sense amplifierwith an input common-mode range that extends from-0.1V to +65V together with protection against negative inductive kickback voltages to -5V. This CSA is well-suitedfor phase current monitoring of inductive loads， such asmotors and solenoids， where pulse width modulation isused to control the drive voltage and current. TheMAX40056 uses an improved technique to help reject common-mode input PWM edges with slew rates up toand beyond ±500V/μs. Common mode rejection ratio（CMRR） is typically 60dB （50V， ±500V/μs input） and140dB DC， typical.

The MAX40056 has an internal +1.5V reference for usewith a nominal +3.3V power supply. The reference can alsobe used to drive an adjoining differential ADC. The referenceis used to offset the output to indicate the directionof the input sensed current. The REF pin can source currentinto external loads and helps to avoid the performance compromises resulting from routing reference voltagesacross noisy PCBs. Alternatively， for higher supplyvoltages and higher full-scale output swings， the internalreference can be overridden by a higher voltage， externalreference.

The internal or external reference can be used to definethe trip threshold for the integrated overcurrent comparator.This can provide immediate indication of an overcurrentfault condition.

The MAX40056 operates over the full -40°C to +125°Ctemperature range and runs from a supply voltage of+2.7V to +5.5V. It is offered in a 2.02mm x 1.4mm 8-pinwafer-level package （WLP） and 8-pin μMAX packages.

MAX40056主要优势和特性：

● Fast， 2μs PWM Edge recovery （1%） from500V/μs PWM Edges

● 60dB AC CMRR Rejection at 50V， ±500V/μs PWMEdges

● 140dB DC CMRR Rejection

● -0.1V to +65V Input Voltage Range

● -5V to +70V Protective Immunity

● 300kHz， -3dB Bandwidth

● Multiple Gain Options; 10V/V， 20V/V， 50V/V

● Internal， 1% Reference for Bidirectional Offset

● 5μV （Typ） Input Offset Voltage

● Rail-to-Rail Output

● 2.02mm x 1.4mm WLP-8 and 8-pin μMAX

● -40℃ to +125℃ Temperature Range

MAX40056应用：

● PWM H-Bridge Motor In-line/In-phase/Winding Current Sensing

● Solenoid Current Sensing

● Current Monitoring of Inductive Loads

● Battery Stack Monitors

● Automotive

图1.MAX40056简化框图

图2.MAX40056应用电路：马达控制在线电流检测

图3.MAX40056应用电路：三相伺服马达的电流检测

评估板MAX40056 EVK

The MAX40056 evaluation kit （EV kit） is a fully assembled electrical demonstration kit that provides a proven design to evaluate the MAX40056F/MAX40056T/MAX40056U high-precision， high-voltage， bidirectional current sense amplifier for PWM applications， such as servo motor con­trol and solenoid drive. The MAX40056F/MAX40056T/ MAX40056U are ideal for 48V， or less BLDC， induction motor applications （such as robotics）， pick-and-place machines， 3D prints， or other servo motor control systems.

This EV kit demonstrates the MAX40056FAUA+ in an 8-pin μMAX package， with Gain = 50V/V. For other available pin-compatible options （MAX40056TAUA+， Gain = 20V/V， MAX40056HAUA+， Gain = 10V/V）， contact the factory.

评估板MAX40056 EVK主要特性：

Precision Real-Time Current-Monitoring with Fault Detection

Internal Available1.5V Reference

-0.3V to +65V Input Common Mode Range

-40℃ to +125℃° Temperature Range

Evaluates 8-μMAX MAX40056FAUA+ Device

Proven PCB Layout

Fully Assembled and Tested

图4.评估板MAX40056 EVK外形图

图5.评估板MAX40056 EVK电路图

评估板MAX40056 EVK材料清单：

图6.评估板MAX40056 EVK PCB设计图：顶层装配图

图7.评估板MAX40056 EVK PCB设计图：左：顶层丝印;右：底层

图8.评估板MAX40056 EVK PCB设计图：左：顶层布局;右：底层丝印