MLX90217_12 Datasheet, PDF (2/9 Pages) Melexis Microelectronic Systems – Hall-Effect Geartooth Sensor

MLX90217
Hall-Effect Geartooth Sensor
Functional Diagram
Hall
Plate
Amplifier
Voltage
Regulator
Logic
Protected
Output
1
2
3
Pin 1 - V_DD (Supply)
Pin 2 - V_SS (Ground)
Pin 3 - Output
Note: Static sensitive device, please observe ESD
precautions.
Description
The MLX90217 is a self adjusting digital output
rotary position gear tooth sensor designed for use
in automotive camshaft sensing as well as other
speed sensing applications. It is designed to be
used with a bias magnet south facing the back
(non-marked) side of the IC. The device has an
open collector output which is short circuit
protected.
The MLX90217 is a sophisticated IC featuring an
on-chip 10-bit A/D Converter and logic that acts
as a digital sample and hold circuit. A separate 4-
bit A/D converter provides a fixed hysteresis. The
90217 does not have a chopper delay. The 90217
uses a single Hall plate which is immune to rotary
alignment problems. The bias magnet can be
from 50 to 400mT.
As the signal is sampled, the logic recognizes an
increasing or decreasing flux density. The output
will turn on (BOP) after the flux has reached its
peak and decreased by an amount equal to the
hysteresis. Similarly the output will turn off (BRP)
after the flux has reached its minimum value and
increased by an amount equal to the hysteresis.
3901090217
Rev.010
Page 2
Mar/12