DRV421_16 Datasheet, PDF (1/44 Pages) Texas Instruments – Integrated Magnetic Fluxgate Sensor for Closed-Loop Current Sensing

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DRV421
SBOS704B – MAY 2015 – REVISED MARCH 2016
DRV421 Integrated Magnetic Fluxgate Sensor for Closed-Loop Current Sensing
1 Features
•1 High-Precision Integrated Fluxgate Sensor
– Offset and Drift: ±8 µT max, ±5 nT/°C typ
• Extended Current Measurement Range
– H-Bridge Output Drive: ±250 mA typ at 5 V
• Precision Shunt Sense Amplifier
– Offset and Drift (max): ±75 µV, ±2 µV/°C
– Gain Error and Drift (max): ±0.3%, ±5 ppm/°C
• Precision Reference
– Accuracy and Drift (max): ±2%, ±50 ppm/°C
– Pin-Selectable Voltage: 2.5 V or 1.65 V
– Selectable Ratiometric Mode: VDD / 2
• Magnetic Core Degaussing Feature
• Diagnostic Features: Overrange and Error Flags
• Supply Voltage Range: 3.0 V to 5.5 V
• Fully Specified Over the Extended Industrial
Temperature Range of –40°C to +125°C
3 Description
The DRV421 is designed for magnetic closed-loop
current sensing solutions, enabling isolated, precise
dc- and ac-current measurements. This device
provides both, a proprietary integrated fluxgate
sensor, and the required analog signal conditioning,
thus minimizing component count and cost. The low
offset and drift of the fluxgate sensor, along with an
optimized front-end circuit results in unrivaled
measurement precision.
The DRV421 provides all the necessary circuit blocks
to drive the current-sensing feedback loop. The
sensor front-end circuit is followed by a filter that can
be configured to work with a wide range of magnetic
cores. The integrated 250-mA H-Bridge drives the
compensation coil and doubles the current
measurement range, as compared to conventional
single-ended drive methods. The device also
provides a precision voltage reference and shunt
sense amplifier to generate and drive the analog
output signal.
2 Applications
• Closed-Loop DC- and AC-Current Sensor
Modules
• Leakage Current Sensors
• Industrial Monitoring and Control Systems
• Overcurrent Detection
• Frequency, Voltage, and Solar Inverters
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
DRV421
WQFN (20)
4.00 mm × 4.00 mm
(1) For all available packages, see the package option addendum
at the end of the datasheet.
Typical Application
3.3 V or 5 V
optional
magnetic
core
RSHUNT
compensation
coil
return current
conductor
(optional)
1
DRV421
Fluxgate Sensor Front-End
Fluxgate
Sensor
Integrator
and
Filter
H-Bridge
Driver
Shunt
Sense
Amplifier
primary
current
conductor
Device Control and Degaussing
Reference
ADC
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.