IC-TW28 Datasheet, PDF (23/80 Pages) IC-Haus GmbH – 10-BIT SIN/COS INTERPOLATOR

W^iCIT^-H^TA^WU²TO⁸-C1A0L-BIBITRSATINIO/CNOASNINDTLEINREPODLRAIVTp^{OERrReliminary}
Rev D2, Page 23/80
Configuration Resistors
In pin configuration mode (PINCFG = 3.3 V), the
iC-TW28 is configured by applying different voltages
to the configuration inputs C0 – C3. Each configura-
tion input recognizes 12 different voltage levels. The
desired voltage levels are typically set using a resistive
voltage divider on each of the configuration inputs as
shown in Figure 19. Thus, only 8 resistors are required
to completely configure the iC-TW28.
Do not use
decoupling caps!
V_DD
R01
R02
V_DD
R11
R12
V_DD
R21
R22
V_DD
R31
R32
AV DD
xSS/C0
iC-TW28
SCLK/C1
SI/C2
SO/C3
Figure 19: Pin Configuration Resistors
The resistors should be located as close to the con-
figuration input pins as possible and no decoupling
capacitors should be used. EIA E48 series 2% resis-
tors or E96 series 1% resistors are recommended to
guarantee reliable operation under all conditions.
SPI Port
The iC-TW28 provides a standard SPI (Serial Periph-
eral Interface) slave port that can be used for de-
vice configuration and communication with a host pro-
cessor or microcontroller in serial configuration mode
(PINCFG = 0 V). Connect the SPI port pins to the host
processor or microcontroller as shown in Figure 20.
iC-TW28
xSS/C0
SCLK/C1
SI/C2
SO/C3
3.3V Host µP
or µC
xCS
SCLK
MO
MI
Figure 20: SPI Port Connection
If the host processor or microcontroller can be discon-
nected, the SPI port pins must be pulled up or down as
shown in Figure 20. Do not allow any of the SPI port
pins to float.
Although Figure 20 shows a single-device application,
multiple iC-TW28’s can also communicate over a single
SPI channel to a host processor or microcontroller. See
Bussing Multiple iC-TW28s on page 75 and Chaining
Multiple iC-TW28s on page 76 for more information.
Reserved Pins
All reserved pins must be tied to ground as shown in
Figures 10, 11, and 12 for proper operation. Do not
allow any of the reserved pins to float.