0 to 70V, High-Precision Current-Sense Amplifier

The MAX49921 is high-precision, unidirectional current-sense amplifier (CSA) with an operating input common-mode 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 reverse-battery and high-voltage spikes. The MAX49921 is well-suited for current monitoring of inductive loads, such as DC motors and solenoids, where common-mode voltages can become negative due to inductive kickback, reverse-battery 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

* Automotive Current Sensing * Battery Current Monitoring * Current Monitoring of Inductive Loads * High- and Low-Side Precision Current Sensing * Precision High-Voltage Current Monitoring * Solenoid Current Sensing * Supercapacitor Charge/Discharge Monitoring

* 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