Electronics Technology


New MR sensors deliver highly accurate and robust performance

19 November 2003 Electronics Technology

Philips Semiconductors offers magneto-resistive (MR) sensors with coils integrated into the housing that compensate for both temperature drift and sensor offset. Magnetic field sensors are commonly used to measure the earth's field, for compass and navigation systems in the automotive industry. They are also increasingly popular in traffic detection and flow control systems, where their sensitivity is high enough to allow identification of individual vehicle types. Another application is in compensation circuits, which automatically eliminate geometry errors produced by changes in the magnetic environment around TVs and monitors.

Available through Arrow Altech Distribution, the KMZ51 sensor, by eliminating the need for external coils, simplifies system design in applications requiring the measurement of weak magnetic fields, allowing the inherent sensitivity, stability and high accuracy of the magnetoresistive effect to be cost-effectively exploited.

The integrated coils have an excellent magnetic coupling factor, so the KMZ51 also has very low power consumption, allowing it to operate from a 5 V supply. Uniquely, even operating at this low supply voltage the sensor requires no DC-to-DC up-converter to provide sufficient coil currents, as required by some sensors with integrated coils under the same conditions.

Compensation for temperature drift and sensor offset is essential in weak-field measurements, otherwise the magnetic effects they produce can completely swamp the target magnetic field. The flipping coil periodically applies brief (3 to 5 µs) magnetic pulses to the sensor, first in one direction, then the other, which 'flips' over the output characteristic of the sensor (which is bi-stable). After rectification and smoothing, the time-averaged output signal is then free from sensor offset. The compensation coil uses an electromagnetic feedback loop to ensure the sensor always operates at its 'null-point', where both sensor offset and signal characteristic are unaffected by temperature fluctuations.

For more information contact Rodney Farrow, Arrow Altech Distribution, 011 923 9600, [email protected]



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Reference board for cardio monitoring
Altron Arrow Telecoms, Datacoms, Wireless, IoT
The STDES-ESP01 reference board from STMicroelectronics demonstrates the capability of the ST1VAFE6AX and ST1VAFE3BX biosensors to detect ECG and SCG signals.

Read more...
ST MCUs extend ultra-low power innovation
Altron Arrow DSP, Micros & Memory
STMicroelectronics has introduced new STM32U3 microcontrollers with cutting-edge power-saving innovations that ease deployment of smart connected tech, especially in remote locations.

Read more...
Multicell battery monitoring
Altron Arrow Power Electronics / Power Management
The LTC6811 from Analog Devices is a multicell battery stack monitor that measures up to 12 series connected battery cells with a total measurement error of less than 1,2 mV.

Read more...
Innovative satellite navigation receiver
Altron Arrow Telecoms, Datacoms, Wireless, IoT
STMicroelectronics has released an innovative satellite navigation receiver to democratise precise positioning for automotive and industrial applications.

Read more...
LED driver for industrial power supply indication
Altron Arrow Editor's Choice Circuit & System Protection
A simple and small solution for driving an LED to provide visual feedback in the presence/absence of a system’s power using a chip not originally designed for this purpose.

Read more...
High-voltage step-down DC-DC converter
Altron Arrow Power Electronics / Power Management
The MAX17793 is a high-efficiency, high-voltage, synchronous step-down DC-DC converter with integrated MOSFETs operating over an input voltage range of 3 to 80 V.

Read more...
High-speed SAR ADC simplifies design
Altron Arrow Analogue, Mixed Signal, LSI
The ADI AD4080 simplifies data converter integration by integrating a low drift reference buffer, low dropout regulators and a 16K result data FIFO buffer.

Read more...
Arduino platform with Analog Devices technology for flexible industrial control
Altron Arrow Editor's Choice DSP, Micros & Memory
Software-configurable systems enable industrial OEMs to deliver unprecedented flexibility to the factory floor, while simplifying product complexity.

Read more...
Ultra-low power Bluetooth connectivity
Altron Arrow Telecoms, Datacoms, Wireless, IoT
Silicon Labs’ delivers robust security and processing for common Bluetooth devices, while BG24L supports advanced AI/ML acceleration and Channel Sounding.

Read more...
xG24 is now Bluetooth 6 certified
Altron Arrow Telecoms, Datacoms, Wireless, IoT
Silicon Labs has been closely following the development of Bluetooth Channel Sounding, and is proud to announce that their xG24 SoCs and xGM240 modules are now Bluetooth 6.0 certified.

Read more...