SBOS704B May   2015  – March 2016 DRV421

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fluxgate Sensor
      2. 7.3.2  Integrator-Filter Function and Compensation Loop Stability
      3. 7.3.3  H-Bridge Driver for Compensation Coil
      4. 7.3.4  Shunt Sense Amplifier
      5. 7.3.5  Overrange Comparator
      6. 7.3.6  Voltage Reference
      7. 7.3.7  Overload Detection and Control
      8. 7.3.8  Magnetic Core Demagnetization
      9. 7.3.9  Search Function
      10. 7.3.10 Error Flag
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Magnetic Core Design
      2. 8.1.2 Protection Recommendations
    2. 8.2 Typical Application
      1. 8.2.1 Closed-Loop Current Sensing Module
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Differential Closed-Loop Current Sensing Module
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
      3. 8.2.3 Using the DRV421 in ±15-V Sensor Applications
  9. 9 Power-Supply Recommendations
    1. 9.1 Power-Supply Decoupling
    2. 9.2 Power-On Start Up and Brownout
    3. 9.3 Power Dissipation
      1. 9.3.1 Thermal Pad
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • 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

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

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.

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

DRV421 sch_bos704.gif