NSE-5310 Datasheet, PDF (8/21 Pages) ams AG – Miniature Position Encoder SOIC with Zero Reference and I²C Output

NSE-5310
Data Sheet - Detailed Description
7 Detailed Description
The TRACKER measures the spatially varying magnetic field produced by moving a multi-pole magnetic strip over a Hall sensor array on the
NSE-5310 chip (see Figure 3). The internal sinusoidal (SIN) and phase-shifted sinusoidal (COS) signals are filtered and transformed into angle
(ANG) and magnitude (MAG), representing the absolute linear position within a 2 mm pole pair on the magnet. Interpolation with 12 bit (4096)
resolution yields 0.5 µm position resolution. Automatic gain control (AGC) adjusts for DC bias in the magnetic field and provides a large
magnetic field dynamic range for high immunity to external magnetic fields. The absolute magnitude of the magnetic field intensity is used to
detect the end of the magnetic strip and serves as a built-in zero reference. The length of the magnetic strip determines the maximum measured
stroke.
Note: Hall sensor array and on-chip digital encoder yield absolute position within a pole pair. Use a system processor to count pole pair
crossings for long-range absolute position.
Figure 3. Hall Sensor Array
0. 488 µm Resolution 4096 Counts / 2 mm (Counts / 360°)
90° Sine
2 mm per N- S Pair
Moving Magnet
NS N S NS
Hall Sensor Array
Mag
ϕ
0°
180°
Cos
270°
+Sine
-Sine
Sine
+Cos
Cos
-Cos
Amplifier with
Automatic Gain ADC
Control
Sine
Angle (ϕ)
DSP
Cos
Magnitude
Digital Filter
The over travel pole crossing provides a precision home position and eliminates the need for a secondary zero reference sensor.
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