compensation

coil

primary

current

conductor

magnetic

core

DRV421

return current

conductor

(optional)

3.3 V or 5 V

ADC

optional

Fluxgate

Sensor

Integrator

and

Filter

Device Control and Degaussing

Reference

H-Bridge

Driver

Shunt

Sense

Amplifier

Fluxgate Sensor Front-End

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DRV421

SBOS704A – MAY 2015 – REVISED JULY 2015

DRV421 Integrated Magnetic Fluxgate Sensor for Closed-Loop Current Sensing

1 Features

3 Description

The DRV421 is designed for magnetic closed-loop

1

•

High-Precision Integrated Fluxgate Sensor

current sensing solutions, enabling isolated, precise

–

Offset and Drift: ±8 µT max, ±5 nT/°C typ

dc-

and

ac-current

measurements.

This

device

•

Extended Current Measurement Range

provides

both,

a

proprietary

integrated

fluxgate

sensor, and the required analog signal conditioning,

–

H-Bridge Output Drive: ±250 mA typ at 5 V

thus minimizing component count and cost. The low

•

Precision Shunt Sense Amplifier

offset and drift of the fluxgate sensor, along with an

–

Offset and Drift (max): ±75 µV, ±2 µV/°C

optimized

front-end

circuit

results

in

unrivaled

measurement precision.

–

Gain Error and Drift (max): ±0.3%, ±5 ppm/°C

•

Precision Reference

The DRV421 provides all the necessary circuit blocks

to drive the current-sensing feedback loop. The

–

Accuracy and Drift (max): ±2%, ±50 ppm/°C

sensor front-end circuit is followed by a filter that can

–

Pin-Selectable Voltage: 2.5 V or 1.65 V

be configured to work with a wide range of magnetic

–

Selectable Ratiometric Mode: VDD/2

cores. The integrated 250-mA H-Bridge drives the

compensation

coil,

while

doubling

the

current

•

Magnetic Core Degaussing Feature

measurement

range,

compared

to

conventional

•

Diagnostic Features: Overrange and Error Flags

single-ended

drive

methods.

The

device

also

•

Supply Voltage Range: 3.0 V to 5.5 V

provides a precision voltage reference and shunt

•

Fully Specified Over the Extended Industrial

sense amplifier to generate and drive the analog

output signal.

Temperature Range of –40°C to +125°C

Device Information (1)

2 Applications

PART NUMBER

PACKAGE

BODY SIZE (NOM)

•

Closed-Loop DC- and AC-Current Sensor

DRV421

WQFN (20)

4.00 mm × 4.00 mm

Modules

(1) For all available packages, see the package option addendum

•

Leakage Current Sensors

at the end of the datasheet.

•

Industrial Monitoring and Control Systems

Typical Application

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.