The TMR40xx series of geartooth sensor adopts a unique push-pull Wheatstone bridge design. This design includes a single-channel or dual-channel Wheatstone full bridge composed of four or eight unshielded high-sensitivity tunneling magnetoresistance (TMR) sensing elements. The Wheatstone bridge provides a differential voltage output along the gradient of the applied magnetic field along the sensor’s sensing direction.

The dual-channel Wheatstone full bridge generates two orthogonal sine/cosine voltage output signals to measure the position of the gear rotation and detect the direction of rotation. The high-sensitivity performance of the TMR40xx series enables detection of small magnetic field changes, and its output signal has good temperature stability.

Description

Features and benefits

••Tunneling magnetoresistance (TMR) technology

••High saturation field allows operation in large DC magnetic field

••High sensitivity to magnetic gradient

••Compatible to small pitch gear measurement

••Sine/cosine signal output with accurate phase difference••

Excellent resistance to external magnetic field interference

••Wide air gap tolerance

••DC (zero speed) operation

••Excellent thermal stability

••Compact package

••RoHS and REACH compliant

Applications

••Gear speed and direction measurement

••Linear and angular speed sensing

••Linear and angular displacement sensing

••Magnetic scale

••Magnetic encoder