NSE-5310_07 Datasheet, PDF (15/22 Pages) ams AG – Miniature Position Encoder with Zero Reference and IC Output

NSE-5310
Datasheet - Application Information
Figure 12. PWM Output Signal
Position
0 µm
(Pos 0)
PW_MIN
1µs
1999.5 µm
(Pos 4095)
PW_MAX
1/f_PWM
4098µs
4097µs
8.7 Magnetic Strip Requirements
The NSE-5310 requires a magnetic strip with alternate poles (North-South) of pole length of 1 mm and pole pair length of 2 mm. A half pole is
required at each end of the strip. The length of the strip determines the maximum measured stroke; it must be 3 mm greater than the stroke in 1
mm increments (1.5 mm on each end).
A circular magnet may be used to achieve off-axis rotary encoding.
Table 13. Magnetic Strip Requirements
Parameter
Value
Note
Pole length
1 mm
Pole pair length
2 mm ± 1.2%
Accuracy of magnetic pole length determines accuracy of linear
measurement
Magnetic strip length
Stroke + 3 mm
The magnet strip must be in 1 mm increments. A ½ pole is required
at each end.
Magnetic strip area
1 mm X 2 mm
Size recommended for TSSOP package
Magnetic field temp drift
-0.2%/K max
Recommended - for example Samarium Cobalt ReComa28 is -
0.035%/K
8.7.1 Mounting the Magnet
Vertical Distance: As a rule of thumb, the gap between chip and magnet should be ½ of the pole length, that is Z=0.5mm for the 1.0mm pole
length of the magnets. However, the gap also depends on the strength of the magnet. The NSE-5310 automatically adjusts for fluctuating
magnet strength by using an automatic gain control (AGC). The vertical distance should be set such that the NSE-5310 is in the “green” range.
See Z-axis Range Indication (“Red/Yellow/Green” Indicator) on page 14 for more details.
Alignment of Multi-pole Magnet and IC: When aligning the magnet strip or ring to the NSE-5310, the centerline of the magnet strip should
be placed exactly over the Hall array. A lateral displacement in Y-direction (across the width of the magnet) is acceptable as long as it is within
the active area of the magnet. The active area in width is the area in which the magnetic field strength across the width of the magnet is constant
with reference to the centerline of the magnet.
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