IC-MHM Datasheet, PDF (23/63 Pages) IC-Haus GmbH – 14-BIT ABSOLUTE ANGLE HALL ENCODER

iC-MHM
14-BIT ABSOLUTE ANGLE HALL ENCODER
Rev D1, Page 23/63
TLF
Value
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
Tracking
Loop
Frequency
11.5 MHz
5.75 MHz
3.83 MHz
2.88 MHz
2.3 MHz
1.92 MHz
1.64 MHz
1.44 MHz
Address 0x00; bits 4:2
Permissible Magnet Rotation Speed [RPM]
AVGFILT = 0 (No Filtering)
AVGFILT = 1 AVGFILT = 2
9 bit 10 bit 11 bit 12 bit
9 ... 16 bit
1347 656 673 828 336 914 168 457 42 114
21 057
673 828 336 914 168 457 84 229 21 057
10 529
449 219 224 609 112 305 56 152 14 038
7 019
336 914 168 457 84 229 42 114 10 529
5 264
269 531 134 766 67 383 33 691 8 423
4 211
224 609 112 305 56 152 28 076 7 019
3 510
192 522 96 261 48 131 24 065 6 016
3 008
168 457 84 229 42 114 21 057 5 264
2 632
AVGFILT = 3
10 529
5 264
3 510
2 632
2 106
1 755
1 504
1 316
Table 21: Tracking Loop Frequency and Maximum Magnet Rotation Speed for fsys = 11.5 MHz
MULTITURN INTERFACE
The iC-MHM provides a dedicated SSI master interface
(the multiturn interface) which is used to read multiturn
position (turns count) from an external multiturn counter
or sensor. The turns count value is synchronized with
the singleturn position (angle) from the iC-MHM to form
the complete absolute position value which is then avail-
able via the main serial interface in BiSS, SSI, or SPI
format.
When enabled (SBL_MTI =/ 0), the iC-MHM reads the
multiturn position at startup and uses it to initialize its
internal multiturn counter. In addition, during operation,
the multiturn position continues to be read via the multi-
turn interface approximately every 1.3 ms (Elec. Char.
item no. I001) and compared to the internal multiturn
position. If the internal multiturn counter value and the
external multiturn count differ, the internal value is re-
placed by the new value from the multiturn interface
and bit ERR_MT in the error status register is set. This
activates the error output (pin NERR low) and activates
the error bit in the BiSS SCD, SPI position read com-
mand response, and extended SSI frame (nERR = nE =
0). Refer to STATUS REGISTERS on page 30 for more
information.
The SSI multiturn interface uses dedicated clock (MCL)
and data (MDI) pins to read the multiturn position from
an external device as shown in Figure 15.
MCL
...
...
...
MDI
MT()
SYNC()
nERROR()
'0'
Figure 15: SSI Multiturn Interface Operation
The iC-MHM supplies the SSI clock at pin MCL for the
external multiturn sensor at a frequency determined by
parameter CF_MTI. The external multiturn sensor must
then clock out the required number of multiturn position,
synchronization, and error bits, followed by a trailing
zero. If the data transmission does not end in a zero or
if one of the error bits is active (0), status bit ERR_MTI
in the error status register is set. This activates the error
output (pin NERR low) and activates the error bit in the
BiSS SCD, SPI position read command response, and
extended SSI frame (nERR = nE = 0). Refer to STATUS
REGISTERS on page 30 for more information.
Clock Frequency (CF_MTI)
Parameter CF_MTI determines the clock frequency
used by the SSI multiturn interface to read the external
multiturn sensor.
CF_MTI
Value
0
1
Address 0x02; bit 0
Clock Frequency
fsys/8 (1.4 MHz at fsys = 11.5 MHz)
fsys/64 (180 kHz at fsys = 11.5 MHz)
Table 22: Clock Frequency