EBx7800 family Sensor modules with incremental output for passive measurement scales.

The sensor modules from the EBx7800 family are sensor modules specifically for measuring ferromagnetic tooth structures (passive measurement scales). 

The sensor modules offer

  • Differential and extremely low harmonic output signals
  • Variants for different tooth pitches and with 1VSS or TTL output 
  • Excellent accuracy and high input frequencies
  • Compact design
  • TTL variants with different interpolation factors

This product family four basic models for you to choose from.

  • EBI7811xBx sensor module without reference and TTL output
  • EBR7811xBx sensor module with reference and TTL output
  • EBI7811xDB sensor module without reference and 1VSS output
  • EBR7811xDB sensor module with reference and 1VSS output

All 5 pitch variants can be selected for all sensor modules. The interpolation can also be set for the modules with TTL output.

The sensor module uses FixPitch sensors and is thus adjusted to the tooth pitch. An optional reference sensor is available, which is synchronized in the ASIC of the sensor module and can generate a reference index, for example, once per rotation. 

The sensor design is based on PerfectWave technology which improves the signal quality by suppressing the harmonics.

Suitable for absolute or incremental applications (linear or rotary motion) e.g.:

  • Motor commutation
  • Speed measurement
  • Linear motor

General information

The sensor modules in the EBx7800 family are FixPitch sensor modules based on the Giant MagnetoResistive (GMR) effect. The sensor modules were developed specifically for use in ferromagnetic tooth structures. A magnet is therefore integrated into every sensor module to stimulate the tooth structure.

This operating principle allows existing machine elements, such as gear wheels or threaded spindles, to be used as measurement scales. These must have a ferromagnetic material property and must have a tooth pitch that matches the sensor pitch.

No specific tooth forms are required. This also allows the sensors to be operated on a hole structure or a square tooth structure.

The sensor signals of the sensor modules are processed in an ASIC and can be used directly from the controller. The modules are set by us during production and are optimally calibrated.

Product variants

Sensor variants

NamePitchWorking distance
EBx7811Oxx1 mm200 µm
EBx7811Pxx2 mm400 µm
EBx7811Qxx3 mm600 µm
EBx7811Rxx0.94 mm (m 0.3)190 µm
EBx7811Sxx1 mm (m 0.5)310 µm

DIGITAL or 1VSS output signal variants

The sensor modules with a digital output signal (EBx7811xBx) have a powerful interpolator unit with a factor of up to 100. This enables the division of a signal period into up to 400 measurement steps and hence generation of a very high resolution.

The sensor modules with an analog output signal (EBx7811xDB) offer a signal gage controller that keeps the output amplitudes within the applicable specification for 1VSS across the temperature range. 

The output signals are provided differentially. An integrated line driver ensures that even larger cable lengths can be used.

Product variants

Basic models

NameOutput signalReference
EBI7811xBxdigital, diff. A/B-
EBR7811xBxdigital, diff. A/B/Zx
EBI7811xDBanalog, diff. Sine/cosine-
EBR7811xDBanalog, diff. Sine/cosine/indexx

EBI7811xxx

These sensor modules only have 2 channels A/B or sine and cosine and they do not supply additional reference signals. The signals are naturally emitted differentially.

EBR7811xxx

The sensor modules are fitted with an additional PCB with a reference sensor. The signals of the reference sensor are processed along with the incremental signals in the ASIC. The modules therefore provide 3 channels with differential signals (A/B/Z).

Data sheets

To the download area

Product information

Your contact person

Design features

Sensitec is increasing the sensor efficiency by means of various design modifications to the chip layout.  The patented solutions, described more closely below, also contribute to better signal quality, reduced sensitivity to stray fields and increased control accuracy. 

FixPitch

FixPitch sensors are adjusted to the pole lengths of the measurement scale, i.e. MR strips are geometrically coordinated to a specific pole length. The sine and cosine signals are generated by distributing the Wheatstone bridge resistors along the single pole. This geometric arrangement contributes to the suppression of the harmonics and a reduction in the sensitivity to stray fields. This optimizes the linearity of the sensor.  

PerfectWave

The PerfectWave design is applied in order to optimize the signal quality of the FreePitch sensors. The MR strips that serve as resistors have a curved form which is used to filter the harmonics when mapping the magnetic field direction in an electric signal. This filtering is implemented using the special geometry and arrangement of the MR strips and does not cause any additional signal propagation delay. The PerfectWave design is particularly effective for small magnetic fields and results in improved linearity, higher accuracy and better signal quality.