IC-TW14 Datasheet, PDF (24/33 Pages) IC-Haus GmbH – IC-PMX Companion Chip

iC-TW14
iC-PMX Companion Chip
Rev A1, Page 24/33
VDD_MSE
VDD_MSE is a read-only register that provides the cal-
culated mean squared error (noise) of the iC-TW14
power supply voltage (V_DD).
Value
0 – 65,535
TEMP_RAW (0x92)
Description
iC-TW14 raw temperature diode ADC value
Table 53: TEMP_RAW Register
Value
0 – 65,535
VDD_MSE (0x91)
Description
iC-TW14 V_DD mean squared error in mV²
Table 52: VDD_MSE Register
TEMP_RAW is filtered to provide a more stable value.
TEMP
TEMP is a read-only register that provides the calcu-
lated die temperature of the iC-TW14.
The actual RMS noise on V_DD is calculated as
Noise [mV] = VDD_MSE
TEMP (0x93)
Bits
Description
15:0
iC-TW14 die temperature in °C
Table 54: TEMP Register
TEMP_RAW
TEMP_RAW is a read-only register that contains the
raw measured ADC value of the iC-TW14’s temperature
diode. This value is used to calculate TEMP.
TEMP is calculated as
VDD TEMP_RAW
TEMP_SLOPE
TEMP = 25 +
·
− TEMP25 ·
4096
32
2048
PRESET PIN (NPRE)
The iC-TW14’s NPRE input pin is used to set SSI_OFS
to define the 0° point of the multiturn data sent to the
external singleturn absolute sensor via the SSI multi-
turn interface. Typically, the NPRE pin is connected to a
pushbutton switch to provide this zeroing function. See
ELECTRICAL CONNECTIONS on page 10 for more
information.
To zero the SSI multiturn position, move the magnet to
the desired 0° point of the SSI multiturn data (where the
multiturn count should change) and activate the NPRE
input for at least 50 ms. When the NPRE input is de-ac-
tivated, SSI_OFS is set to the current value of PMX_ST
(see Figure 2 on page 8) and the FRAM multiturn count
is set to zero. The new SSI_OFS value is then saved to
FRAM (WRITE command) and the iC-TW14 is re-syn-
chronized to the iC-PMX (RESYNC command). See
MODE/CMD on page 19 for more information.
The correct system 0° point is determined by the re-
quirements of the external singleturn absolute sensor
connected to the iC-TW14 based on the number of sync
bits used.
STATUS.NPRE = 1 while the NPRE input is active. See
STATUS on page 14 for more information.