Honeywell's magnetoresistive (MR) sensors are the most sensitive, low field, solid state magnetic sensors available to measure direction and magnitude of magnetic fields from 70 mG (7 nT) to 6 G (0.6 mT). Honeywell's magnetoresistor sensors can determine the change in earth's magnetic field due to the presence of a ferromagnetic object or position within the earth's magnetic field. The high bandwidth allows detection of vehicles and other ferrous objects at high speeds. The sensors are contactless and the working distance is dependent on the ferromagnetic mass it is measuring.
This means that the devices are suitable for many applications other than simple compassing, such as platform levelling or proximity detection for example.

HMC6352 Digital Compass Solution

A more integrated solution in a tiny package, the Honeywell HMC6352 2-Axis Digital Integrated Compass Solution combines a two-axis MR magnetic field sensor design with the required analogue and digital support circuits for heading computation.

By combining the sensor elements and all the processing electronics into a 6.5mm square LCC package, designers will have the simplest solution to integrate low cost and space efficient electronic compasses for wireless phones, consumer electronics, vehicle compassing, and antenna positioning.

Compared with other devices in this range, the HMC6352 removes the requirement for complex wheatstone bridges, biasing circuits or control circuitry.

Features
Wide Field Range: Field range up to ±6 gauss, (earth’s field = 0.5 gauss)
Small Package: Designed for 1- and 2-axis to work together to provide 3-axis (x, y, z) sensing. 1-axis part in an 8-pin SIP or an 8-pin SOIC or a ceramic 8-pin DIP package. 2-axis part in a 16-pin or 20-pin SOIC package .
Solid State: These small devices reduce board assembly costs, improve reliability and ruggedness compared to mechanical fluxgates.
On-Chip Coils: Patented on-chip set/reset straps to reduce effects of temperature drift, non-linearity errors and loss of signal output due to the presence of high magnetic fields. Patented on-chip offset straps for elimination of the effects of hard iron distortion.
Cost Effective: The sensors were specifically designed to be affordable for high volume OEM applications.

   actual size: 10 x 7mm

The HMC1021Z is a single-axis magnetoresistive sensor in an 8-pin SIP package. Field range is +/-6 gauss, resolution is 85 microgauss and sensitivity is 1mV/V/gauss. Used as a single-axis sensor, or with an HMC1022 for three-axis applications.

Features
Wide Field Range: Field range up to ±6 gauss, (earth’s field = 0.5 gauss)
Small Package: Designed for 1- and 2-axis to work together to provide 3-axis (x, y, z) sensing. 1-axis part in an 8-pin SIP or an 8-pin SOIC or a ceramic 8-pin DIP package. 2-axis part in a 16-pin or 20-pin SOIC package .
Solid State: These small devices reduce board assembly costs, improve reliability and ruggedness compared to mechanical fluxgates.
On-Chip Coils: Patented on-chip set/reset straps to reduce effects of temperature drift, non-linearity errors and loss of signal output due to the presence of high magnetic fields. Patented on-chip offset straps for elimination of the effects of hard iron distortion.
Cost Effective: The sensors were specifically designed to be affordable for high volume OEM applications.

Breakthrough design contains a compact, high performance two-axis magnetoresistive sensors on a single chip. Advantages of this patented design include perfectly orthogonal two-axis sensing, ultra small size and low power in a 10-pin miniature surface mount package.

Features
Low Power: Supply voltage could be as low as 1.8V.
Small Package: Available in a 10-pin miniature surface mount package (MSOP) with total mounting envelope of 3mm x 3mm x 1mm.
High Performance: Sensitivity of 1mV/V/gauss with a wide field range up to +/- 6 gauss.
High Accuracy: Nearly perfect orthogonal two-axis sensing (Error < 0.01°) and matched sensitivity on both axis eliminates errors in compassing applications.
On-Chip Coils: Patented on-chip set/reset straps reduces the effects of temperature drift, non-linearity errors and loss of signal output due to the presence of high magnetic fields.

HMC1052L Two-Axis Surface Mount Magnetic Sensor

actual size: 3 x 3 x 0.9mm

The Honeywell HMC1052L is a high performance magnetoresistive sensor design in a single package. The advantages of this design are
magnetoresistive chips positioned for orthogonal two-axis sensing, miniature size and low height profile in a surface mount package.

Each of the magnetoresistive sensors are configured as a 4-element
wheatstone bridges to convert magnetic fields to differential output voltages. Capable of sensing fields below 0.1 milligauss, this sensor offers a compact, low cost, high sensitivity and highly reliable solution for low field magnetic sensing.

Features
Miniature 16-pin LCC Package (3 x 3 x 0.9mm)
Two AMR bridges in one package
Wide field range of +/-6 gauss
1.0mV/V/gauss sensitivity
High accuracy compassing
Low profile for tight space constraints
Patented on-chip set/reset straps

High resolution, low power MR sensor capable of measuring the angle direction of a magnetic field from a magnet with <0.07° resolution. Advantages of measuring field direction versus field strength include: insensitivity to the temperature coefficient of the magnet, less sensitivity to shock and vibration, and the ability to withstand large variations in the gap between the sensor and magnet. These sensors may be operated on 3 volts with bandwidth response of 0-5 MHz. Output is typical Wheatstone bridge.

Applications
Linear Displacement
Angular Displacement
Motor Control
Valve Position
Proximity Detection
Current Spike Detection

Features
No Rare Earth Magnets: Unlike Hall effect devices which may require samarium cobalt or similar “rare earth” magnets, the HMC1501 and HMC1512 can function with Alnico or ceramic type magnets.
Wide Angular Range: HMC1501 - Angular range of ±45° with <0.07° resolution. HMC1512 - Angular range of ±90° with <0.05° resolution.
Effective Linear Range: Linear range of 8mm with two sensors mounted on two ends; range may be increased through multiple sensor arrays operating together.
Absolute Sensing: Unlike incremental “encoding” devices, sensors know the exact position and require no indexing for proper positional output.
Non-Contact Sensing: No moving parts to wear out; no dropped signals from worn tracks as in conventional contact based rotary sensors.
Small Package: Available in an 8-pin surface mount package with case dimensions (exclusive of pins), of 5mm x 4mm x 1.2mm total mounting envelope, with pins of less than 6mm square.
Large Signal Output: Full Scale output range of 120mV with 5V of power supply.
Demo Board available with an HMC1512 sensor, a magnet assembly and an amplification circuit. Used to demonstrate linear position sensing applications.