MAX49921 datasheet(10/14 Pages) MAXIM

10 / 14 page

Detailed Description

The MAX49921 is a high-precision, 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 CSA 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 the device best-suited for high-precision

current measurements. The MAX49921 runs from a single supply voltage of +2.7V to +5.5V, consumes 0.7mA (typ)

quiescent supply current, and features gains of 20V/V and 50V/V.

The MAX49921 is designed for unidirectional operation, allowing current measurements in one direction through the

sense resistor RSENSE. The device output voltage can be estimated as follows:

VOUT = VSENSE x AV

where VSENSE = (VRS+ - VRS-) = the sense voltage across the RSENSE resistor, 100mV for gain of 20V/V, 90mV for

gain of 50V/V, and AV is the gain of the device.

MAX49921

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

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MAX49921 Datasheet(PDF) 10 Page - Maxim Integrated Products