NSE-5310_07 Datasheet, PDF (14/22 Pages) ams AG – Miniature Position Encoder with Zero Reference and IC Output

NSE-5310
Datasheet - Application Information
8.5 Z-axis Range Indication (“Red/Yellow/Green” Indicator)
The NSE-5310 provides several options of detecting the magnet distance by indicating the strength of the magnetic field. Signal indicators
MagINCn and MagDECn are available both as hardware pins (pins 2 and 3) and as status bits in the serial data stream (see Figure 9).
Additionally the LIN status bit indicates the non-recommended “red” range.
The digital status bits MagINC, MagDec, LIN and the hardware pins MagINCn, MagDECn have the following function:
Table 11. Magnetic Field Strength Red-Yellow-Green Indicators
Status Bits
MAG
Hardware Pins
Mag
INC
Mag
DEC
Lin
M11…
M0
Mag Mag
INCn DECn
Description
0
0
0
3F hex
OFF
OFF
No distance change
Magnetic input field OK (GREEN range, ~10-40mT peak amplitude)
Distance increase; this state is a dynamic state and only active while the
0
1
0
3F hex
OFF OFF magnet is moving away from the chip. Magnitude register may change
but regulates back to 3F hex.
Distance decrease; this state is a dynamic state and only active while the
1
0
0
3F hex
OFF OFF magnet is moving towards the chip. Magnitude register may change but
regulates back to 3F hex.
1
1
0
20 hex - 5F
hex
ON
YELLOW range: magnetic field is ~3.4-4.5mT.
OFF The device may still be operated in this range, but with slightly reduced
accuracy.
1
1
1
<20 hex
>5F hex
ON
RED range: magnetic field is <3.4mT (MAG <20) or >54.5mT
ON (MAG >5F). It is still possible to operate the device in the red range, but
not recommended.
8.6 Pulse Width Modulation (PWM) Output
The NSE-5310 also provides a pulse width modulated output (PWM), whose duty cycle is proportional to the relative linear position of the
magnet within one pole pair (2.0 mm). This cycle repeats after every subsequent pole pair:
Position
=
-^t--^o---ⁿ---^â‹---4---0---9---8---
(t_on + t_off)
–
1
(EQ 1)
Where:
Digital position = 0 – 4094
Exception: A linear position of 1999.5µm = digital position 4095 will generate a pulse width of tON = 4097µs and a pause tOFF = 1µs
The PWM frequency is internally trimmed to an accuracy of ±5% (±10% over full temperature range). This tolerance can be cancelled by
measuring the complete duty cycle as shown above.
Operating Conditions: TAMB = -40 to +125ºC, VDD5V = 3.0~3.6V (3V operation) VDD5V = 4.5~5.5V (5V operation) unless otherwise noted.
Table 12. PWM Output Timing Considerations
Symbol
Parameter
Conditions
Min
Typ
Max
Units
f_PWM
PW_MIN
PW_MAX
PWM frequency
Minimum pulse width
Maximum pulse width
Signal period = 4098µs ±5% at
TAMB=25ºC
232
244
256
= 4098µs ±10% at
TAMB= -40 to +125ºC
Hz
220
244
268
Position 0d = 0µm
0.9
1
1.1
µs
Position 4095d = 1999.5µm
3892 4097
4301
µs
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