Texas Instruments' DRV411 is designed to condition InSb Hall elements for use in closed-loop current-sensor modules. The DRV411 provides precision excitation circuitry for the Hall element, effectively eliminating the offset and offset-drift of the Hall element. This device also provides a 250 mA H-bridge for driving the sensor compensation coil, as well as a precision differential amplifier to generate the output signal. The 250 mA drive capability of the H-bridge roughly doubles the current measurement range compared to conventional single-ended drive methods.
The Hall sensor front-end circuit and the differential amplifier employ proprietary offset cancelling techniques. These techniques, along with a high-accuracy voltage reference, significantly improve the accuracy of the overall current-sensor module. The output-voltage is pin-selectable to support a 2.5 V output for use with a 5 V power supply, as well as 1.65 V for 3.3 V sensors.
For optimum heat dissipation, the DRV411 is available in thermally-enhanced 4 × 4 mm QFN and TSSOP-20 with PowerPAD packages. The DRV411 is specified for operation over the full extended industrial temperature range of –40°C to +125°C.
- Optimized for symmetric Hall elements (AKM HW-322, HW-302, or similar)
- Spinning-current Hall sensor excitation
- Elimination of Hall sensor offset and drift
- Elimination of 1/f noise
- Extended current-measurement range
- H-bridge drive capability: 250 mA
- Over-range and error flags
- Precision difference amplifier:
- Offset and drift: 100 µV (max), 2 µV/°C (max)
- System bandwidth: 200 kHz
- Precision reference
- Accuracy: 0.2% (max)
- Drift: 50 ppm/°C (max)
- Pin-selectable for 2.5 V, 1.65 V, and ratiometric mode