iC-TW8 16-BIT SIN/COS INTERPOLATOR
Serial Configuration Mode
Jan 9, 2013 Page SC12/36
Connecting the EEPROM
Connecting the Incremental Sensor
The iC-TW8 requires a 24xx02 through 24xx16
family I2C EEPROM for storage of sensor calibra-
tion data (offset, gain, etc.). The EEPROM con-
nects directly to the iC-TW8 via a dedicated I2C
communication channel using SCL (pin 27) and
SDA (pin 28) as shown in Figure 10. No external
pull-up resistors are required. EESEL (pin 4) of
the TW8 must also be connected to DVSS as
shown.
The iC-TW8 connects directly to magnetic (such as
the iC-SM2L or iC-SM5L) or optical sensors provid-
ing differential Sin/Cos outputs as shown in Figure 11.
Signal amplitude (A) from all four sensor channels
must be in the range of 5 – 350mV as shown in Figure
12 for proper operation with the iC-TW8.
AVDD
SIN+
VDD
Sensor Bridge 0
DVDD
EESEL tied to DVSS.
SIN-
EESEL
1µF
COS+
DVSS
VDD
Sensor Bridge 1
SCL
SDA
WP
SCL VCC
COS-
1µF
SDA
VSS
iC-TW8
WP
EEPROM
24xx
Figure 11: Differential Sensor Connection
iC-TW8
SIN+
Figure 10: EEPROM Connection
A
In serial configuration mode, the Write Protect
(WP) input of the EEPROM is controlled by the
iC-TW8. WP must be disabled via the serial port
during calibration to allow the iC-TW8 to write
parameter values to the EEPROM. In operation,
WP can be left enabled or disabled as required by
the application.
5mV ≤ A ≤ 350mV
0 (VDD/2)
–A
SIN-
0°
180°
360°
Figure 12: Differential Sensor Signal Inputs
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