MLX90316KDC-BDG Datasheet, PDF (23/45 Pages) Melexis Microelectronic Systems – Rotary Position Sensor IC

MLX90316
Rotary Position Sensor IC
Melexis strongly recommend to set ARGC = “1”, AUTO_RG = “1” and RoughGain ≤ 3 for all types of
application. If the magnetic specifications of the application are well known and under control, the
appropriate RoughGain can also be programmed with ARGC set to “0” and AUTO_RG to “1”.
Please note that the angular errors listed in the section 10 are only valid if the AUTO_RG is activated.
AUTO_RG avoids also the saturation of the analog chain and the associated linearity error.
The current gain (RG) can be read out with the PTC-04 and gives a rough indication of the applied
magnetic flux density (Amplitude).
14.4.3. RGThresL, RGThresH Parameters
RGThresL & RGThresH define the boundaries within the gain setting (Rough Gain) is allowed to vary.
Outside this range, the output is set in diagnostic low.
14.5. FILTER
Parameter
FHYST
FILTER
FSWAP
Value
Unit
0 … 11 ; step 0.04
deg
0… 6
0
1
The MLX90316 includes 3 types of filters:
• Hysteresis Filter: programmable by the FHYST parameter
• Low Pass FIR Filters controlled with the Filter parameter
• Low Pass IIR Filter controlled with the Filter parameter and the coefficients FILTER A1 and
FILTER A2
Note: if the parameter FSWAP is set to “1”, the filtering is active on the digital angle. If set to “0”, the
filtering is active on the output transfer function.
14.5.1. Hysteresis Filter
The FHYST parameter is a hysteresis filter. The output value of the IC is not updated when the digital step
is smaller than the programmed FHYST parameter value. The output value is modified when the
increment is bigger than the hysteresis. The hysteresis filter reduces therefore the resolution to a level
compatible with the internal noise of the IC. The hysteresis must be programmed to a value close to the
noise level.
Please note that for the programmable version, the FHYST parameter is set to 4 by default. If you do not
wish this feature, please set it to “0”.
14.5.2. FIR Filters
The MLX90316 features 6 FIR filter modes controlled with Filter = 0…5. The transfer function is described
below:
∑ ^{∑ yn =}
1
j
j
a_i x_n−i
a i=0
i
i=0
3901090316
Rev10
Page 23 of 45
Jul/13