IC-MHM Datasheet, PDF (22/63 Pages) IC-Haus GmbH – 14-BIT ABSOLUTE ANGLE HALL ENCODER

iC-MHM
14-BIT ABSOLUTE ANGLE HALL ENCODER
Rev D1, Page 22/63
HYS
Value
0
1
2
3
Address 0x00; bits 7:6
Hysteresis (Magnet Rotation Angle)
0.00°
0.17°
0.35°
0.70°
Table 19: Hysteresis
Tracking Loop Frequency (TLF)
The optimal frequency of the interpolator tracking loop
for any given application is determined by the maxi-
mum required rotational speed of the magnet (RPM_max),
the required angular position resolution (parameter
RESO_ST), and the averaging filter setting (AVGFILT).
Parameter TLF sets the maximum tracking loop fre-
quency.
TLF
Value
0
1
2
3
4
5
6
7
Address 0x00; bits 4:2
Tracking Loop Frequency
fsys
fsys/2
fsys/3
fsys/4
fsys/5
fsys/6
fsys/7
fsys/8
Table 20: Tracking Loop Frequency
For example, for an application without averaging fil-
tering requiring 12-bit singleturn resolution and a maxi-
mum magnet rotation speed of 50 kRPM, TLF is calcu-
lated as:
11 500 000 · 60
TLF ≤ INT _{2(16 - 12) · 50 000} − 1 = 2
It is recommended to always use the highest TLF value
that provides the required maximum magnet rotation
speed at the required resolution.
When the averaging filter is used (AVGFILT =/ 0), TLF
is independent of the resolution (RESO_ST) and is
calculated as:
fsys · 60
TLF ≤ INT _{2(13 + AVGFILT) · RPMmax} − 1
Where fsys is the system clock frequency (refer to Elec.
Char. item no. 501). To guarantee operation under all
conditions, the minimum fsys of 11.5 MHz should be
used for all calculations.
For example, for an application with medium averaging
filtering requiring a maximum magnet rotation speed of
3 000 RPM, TLF is calculated as:
11 500 000 · 60
TLF ≤ INT _{2(13 + 2) · 3 000} − 1 = 6
In general, higher tracking loop frequencies provide
higher maximum magnet rotation speed at the expense
of reduced accuracy above 5 MHz.
When the averaging filter is not used (AVGFILT = 0),
TLF is calculated as:
fsys · 60
TLF ≤ INT _{2(16 - RESO_ST) · RPMmax} − 1
Where fsys is the system clock frequency (refer to Elec.
Char. item no. 501). To guarantee operation under all
conditions, the minimum fsys of 11.5 MHz should be
used for all calculations.
It is recommended to always use the highest TLF value
that provides the required maximum magnet rotation
speed with the selected level of filtering.
The maximum magnet rotation speed for all settings
of TLF, RESO_ST, and AVGFILT is shown in Table 21.
Exceeding these speeds causes the averaging position
value to lag behind the actual mechanical position of
the magnet. A position lag of ≥ 90 ° results in a dis-
continuity (jump) in the averaging position output and a
BiSS, extended SSI, or SPI warning (nWARN = nW = 0).
It also activates the error output (pin NERR low) if the
incremental outputs are enabled (CFG_IOP = 2). Refer
to DIGITAL I/O PORT on page 26 for more information
on the incremental outputs.