General Description

The MAX49921 is high-precision, unidirectional currentsense

amplifier (CSA) with an operating input commonmode

range from 0 to +70V, though the device is protected

against input common-mode voltages down to -42V

and up to +80V, thus providing protection against reversebattery

and high-voltage spikes. The MAX49921 is wellsuited

for current monitoring of inductive loads, such as

DC motors and solenoids, where common-mode voltages

can 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-precision

current measurements.

The MAX49921 operates from a supply voltage of +2.7V

to +5.5V with a typical quiescent supply at 0.7mA. This

device is specified over the full -40°C to +125°C automotive

temperature range and is AEC-Q100 qualified. The

MAX49921 is offered in a 2mm x 3mm, 8-pin, side-wettable

TDFN package with gain options of 20V/V and

50V/V.

Applications

● Solenoid Current Sensing

● Battery Current Monitoring

● Current Monitoring of Inductive Loads

● High- and Low-Side Precision Current Sensing

● Supercapacitor Charge/Discharge Monitoring

● Precision High-Voltage Current Monitoring

● Automotive Current Sensing

Benefits and Features

● 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, 50V/V

● Rail-to-Rail Output

● 2mm x 3mm, 8-Pin TDFN Package

● -40°C to +125°C Automotive Temperature Range