Maxim MAX49921 0－70V高精度电流检测放大器解决方案

Maxim公司的MAX49921是高精度单向电流检测放大器(CSA),输入共模范围从0V到70V,通过保护, 输入共模范围可低至-42V和高达+80V.低输入失调为±0.5μV(典型),低增益误差为±0.05%(典型),使得MAX49921非常适合用作高精度电流测量.器件工作电压从2.7V到5.5V,典型静态电流为0.7mA,工作温度-40C 到 +125C汽车温度范围,并满足AEC-Q100汽车资质.140dB DC CMRR,-3dB带宽为65kHz.增益选择为20V/V和50V/V.采用2mm x 3mm 8引脚TDFN封装.主要用在电磁线圈电流检测,电池电流监视,感性负载电流监视,高边和低边电流检测,超级电容充/放电监测,精密高压电流监视和汽车电流检测.本文介绍了MAX49921主要特性和优势,简化框图,几种电流测量图以及评估板MAX49921 EVK主要特性,电路图,材料清单和PCB设计图.

The MAX49921 is high-precision, unidirectional currentsenseamplifier (CSA) with an operating input commonmoderange from 0 to +70V, though the device is protectedagainst input common-mode voltages down to -42Vand up to +80V, thus providing protection against reversebatteryand high-voltage spikes. The MAX49921 is wellsuitedfor current monitoring of inductive loads, such asDC motors and solenoids, where common-mode voltagescan become negative due to inductive kickback, reversebattery

conditions, or transient events.

The low input offset of ±0.5μV (typ) and low gain error of±0.05% (typ) make this device best-suited for high-precisioncurrent measurements.

The MAX49921 operates from a supply voltage of +2.7Vto +5.5V with a typical quiescent supply at 0.7mA. Thisdevice is specified over the full -40C to +125C automotivetemperature range and is AEC-Q100 qualified. TheMAX49921 is offered in a 2mm x 3mm, 8-pin, side-wettableTDFN package with gain options of 20V/V and50V/V.

MAX49921主要特性和优势:

● AEC-Q100 Qualified for Automotive Applications

● ±0.5μV (typ) Input Offset Voltage

● ±0.05% (typ) Gain Error

● 0 to +70V Input Voltage Range

● -42V to +80V Protective Immunity

● 65kHz, -3dB Bandwidth

● 140dB DC CMRR

● Gain Options: 20V/V,...