The TLE5027 uses the giant magneto resistive (GMR) effect, which is by a factor >10
more sensitive compared to the Hall-effect. The TLE5027 detects the motion and
position of ferromagnetic magnet structures by measuring the change of the magnetic
field induced by this structure, which can be a magnetic encoder wheel, ferromagnetic
gear wheel or any similar structure. In case of any non-encoder based application like
gear wheels the magnetic field is generated by applying a specially optimized back
bias magnet to the sensor. As the GMR sensor measures the in plane components of
the magnetic field the sensor switches in phase with the edges of a tooth/gap pair of
a gear wheel or north/south pole pair of a magnetic encoder. The very high sensitivity
of the GMR effect enables the TLE5027 to measure very large airgaps with encoder
wheels or be back biased with excellent airgap performance using a low-cost ferrite
material for the magnet.
The sensor has a fast start up time and the sensor switches with its hidden adaptive
hysteresis algorithm, which ensures high accuracy over airgap jumps, vibrations, runout
events ,etc. Within the first 3 magnetic edges after start up the sensor provides the
direction information, which is given as pulse width modulated output.
TLE5027 is well suited for harsh environmental conditions prevalent in automotive or
certain industrial applications by its wide temperature range as well as high ESD and
EMC robustness. In addition the TLE5027 provides the benefit of a very low current
consumption. With its features the TLE5027C is ideal for applications like today’s crankshaft
or transmission speed sensing in automotive or similar industrial applications.
