General Description

The MAX9918/MAX9919/MAX9920 are single-supply,

high-accuracy current-sense amplifiers with a high

input common-mode range that extends from -20V

to +75V. These amplifiers are well suited for current

monitoring of inductive loads such as motors and

solenoids, where common-mode voltages can become

negative due to inductive kickback, reverse-battery

conditions, or transient events.

The MAX9918/MAX9920 feature adjustable gain set

by an external resistive-divider network. The MAX9919

features fixed gains of 45V/V (MAX9919F) and 90V/V

(MAX9919N).

The

MAX9918/MAX9919/MAX9920

operate as unidirectional amplifiers when VREFIN = GND

and as bidirectional amplifiers when VREFIN = VCC/2.

The MAX9920 attenuates the input signal by a factor of

4 at the input level-shifting stage allowing the device to

sense voltages up to 200mV (unidirectional operation) or

±100mV (bidirectional operation).

The MAX9918/MAX9919/MAX9920 operate with a

single 5V supply voltage, are fully specified over the

-40°C to +125°C automotive temperature range, and are

available in an 8-pin SOIC package.

Applications

● H-Bridge Motor Current Sensing

● Solenoid Current Sensing

● Current Monitoring of Inductive Loads

● High- and Low-Side Precision Current Sensing

● Super-Capacitor Charge/Discharge Monitoring

● Precision High-Voltage Current Monitoring

● Automotive

Benefits and Features

● Reduce Protective Clamping for High Inductive

Kickback Voltage

• -20V to +75V Input Common-Mode Voltage Range

● Supports Wide Range of Precision AC and DC

Current Sensing Applications

• Uni- or Bidirectional Current Sensing

• 0.6% (max) Gain Accuracy Error

• 400µV (max) Input Offset Voltage

• 120kHz, -3dB Bandwidth (MAX9919N)

• Reference Input for Bidirectional OUT

• Rail-to-Rail Output

● Saves Board Space

• 8-Pin SOIC Package

• Single-Supply Operation (4.5V to 5.5V)

● AEC-Q100 Qualified (MAX9918ASA/V+,

MAX9919FASA/V+, MAX9919NASA/V+,

MAX9920ASA/V+ Only)

19-5015; Rev 10; 7/19

Click

here for production status of specific part numbers.

Note: All devices operate over the -40°C to +125°C temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

/V denotes an automotive qualified part.

*EP = Exposed pad.

M

ø2B

ø1B

ADC

REF

A

INPUT STAGE

LEVEL SHIFTER

RSENSE

VBATT

ADJUSTABLE GAIN

VCC

VCC

RS+

RS-

FB

OUT

REFIN

R2

R1

GND

GND

SHDN

ø2B

ø1A

MAX9918

MAX9920

µC

Typical Operating Circuit

Ordering Information/Selector Guide

PART

VSENSE

(mV)

GAIN

(V/V)

PIN-

PACKAGE

MAX9918ASA+

±50

Adjustable

8 SO-EP*

MAX9918ASA/V+

±50

Adjustable

8 SO-EP*

MAX9919FASA+

±50

45

8 SO-EP*

MAX9919FASA/V+

±50

45

8 SO-EP*

MAX9919NASA+

±50

90

8 SO-EP*

MAX9919NASA/V+

±50

90

8 SO-EP*

MAX9920ASA+

±200

Adjustable

8 SO-EP*

MAX9920ASA/V+

±200

Adjustable

8 SO-EP*

MAX9918/MAX9919/MAX9920

-20V to +75V Input Range,

Precision Uni-/Bidirectional,

Current-Sense Amplifiers