IC-TW14 Datasheet, PDF (18/33 Pages) IC-Haus GmbH – IC-PMX Companion Chip

iC-TW14
iC-PMX Companion Chip
Rev A1, Page 18/33
SIN_OFS_COR, COS_OFS_COR
SIN_OFS_COR and COS_OFS_COR are read/write
registers containing the offset correction for the sine
and cosine values (respectively) calculated from read-
ing the singleturn Hall sensors in the iC-PMX.
SIN_OFS_COR (0x1A), COS_OFS_COR (0x1B)
Value
Description
±32,767 Sin/cos calculation offset corrections
Table 24: OFS_COR Registers
SIN_OFS_COR and COC_OFS_COR are 2’s-comple-
ment numbers used to calculate SIN and COS. See SIN
and COS Registers on page 21 for more information.
GAIN_COR
GAIN_COR is a read/write register containing the gain
correction for the sine value calculated from reading
the singleturn Hall sensors in the iC-PMX.
Value
±128
GAIN_COR (0x1C)
Description
Sine calculation gain correction
Table 25: GAIN_COR Register
AMP_MAG_LOSS
AMP_MAG_LOSS is a read/write register used to set
the AMP value below which it is assumed the magnet
is no longer within proper range of the iC-PMX.
Value
0 – 65,535
AMP_MAG_LOSS (0x1E)
Description
Magnet lost amplitude in units of 0.1 kA/m
Table 27: AMP_MAG_LOSS Register
An AMP value less than AMP_MAG_LOSS generates
a magnet lost fault (STATUS.MLF = 1) and an SSI mul-
titurn data not ready condition (STATUS.NOSSI = 1).
See STATUS on page 14 for more information. This
condition also sets the MRDY pin low and disables the
SSI multiturn interface to signal the fault to the external
singleturn absolute sensor.
TEMP25
TEMP25 is a read/write register containing the voltage
of the iC-TW14’s temperature diode at 25°C.
Value
0 – 65,535
TEMP25 (0x1F)
Description
Temperature Voltage at 25°C in mV
GAIN_COR is a 2’s-complement number calculated as
Table 28: TEMP25 Register
GAIN_COR = INT(Desired Sine Gain · 16)
which is used to calculate SIN and COS. See SIN
and COS Registers on page 21 for more information.
GAIN_COR should be adjusted so that the ratio of
SIN_PEAK to COS_PEAK is a close to 1 as possible.
See SIN_PEAK and COS_PEAK Registers on page 21
for more information.
Note that a negative gain correction value inverts the
sine signal which reverses the rotation direction of
PMX_ANGLE relative to the magnet rotation direction.
AUTO_GAIN
AUTO_GAIN is a read/write register used to enable
automatic gain control on iC-PMX Hall gain.
Value
0
1
2 – 65,535
AUTO_GAIN (0x1D)
Description
Automatic gain control disabled
Automatic gain control enabled
Reserved (not used)
Table 26: AUTO_GAIN Register
TEMP25 is a positive number equal to the tempera-
ture diode’s voltage at 25°C in millivolts. It is used by
the iC-TW14 to calculate the temperature reported in
the TEMP register. See TEMP on page 24 for more
information.
The nominal value of TEMP25 is 1370. TEMP25 can
be calibrated by measuring the die temperature of the
iC-TW14 using an independent thermometer at two
different temperatures, T₁ and T₂ and recording the
corresponding TEMP_RAW₁ and TEMP_RAW₂ values
and the VDD register value. TEMP25 is then calculated
as
TEMP25 = ^VDD · ^{(T1 − 25) · TEMP_RAW 2 − (T2 − 25) · TEMP_RAW 1}
131072
T₁ − T₂
For example, suppose that at 30°C TEMP_RAW =
0x8F3D = 36669, at 80°C TEMP_RAW = 0x7EF5 =
32501, and VDD = 4895 mV. Then TEMP25 should be
set to
4895 (30 − 25) · 32501 − (80 − 25) · 36669
·
= 1385
131072
30 − 80
It is recommended to always enable the automatic gain
control (AUTO_GAIN = 1).