MMA253F中文資料多維科技數(shù)據(jù)手冊(cè)PDF規(guī)格書(shū)

Features and Benefits

? Tunneling Magnetoresistance (TMR) Technology

? Large Output Signal without Amplification

? Dual-Axis 360°Angle Measurement

? Compatible with Wide Range of Supply Voltages

? High Resistance for Low Power Consumption

? Wide Air-Gap Tolerance

? Excellent Thermal Stability

? Compact LGA Package

Applications

? Rotary Position Sensors

? Rotary Encoders

? Contactless Potentiometers

? Valve Position Sensors

? Knob Position Sensors

General Description

The dual-axis output voltages of the MMA253F TMR angle sensor are proportional to the sine and

cosine of the angle of a magnetic field applied parallel to the surface of the sensor, which can be

provided by a small magnet positioned above the device. The MMA253F includes two Wheatstone

bridges, which can be configured to output sine and cosine functions respectively. Each bridge

includes four TMR sensor elements in a push-pull arrangement to produce a best-in-class

peak-to-peak signal as large as 100% of the supply voltage, eliminating the need for amplification

in many applications. Additionally, the unique TMR Wheatstone bridge technology accurately

compensates the output against changes in ambient temperature. This sensor is assembled in a

compact LGA8 package of 3.0 mm ? 3.0 mm ? 0.9 mm.

Operation

A small magnet, placed above the MMA253F, can be used to provide a magnetic field in any

desired orientation parallel to the plane of the MMA253F package. The magnetic field is detected

by TMR sensors in the MMA253F that are composed of two magnetic layers. One layer of the

TMR sensors is a “pinned layer” that is not affected by the magnetic field, and the other is “free

layer,” which has a magnetization that aligns parallel to the applied magnetic field. Because the

TMR effect produces a resistance that is proportional to the sine or cosine of the relative difference

between the free and pinned layer magnetization orientations, the sensor output voltage is

sinusoidally dependent on the angle of the applied magnetic field, thereby providing a measure of

the orientation of the magnet.