AS5050
Datasheet - Application Information
8.1.4 SPI Over Long Distances
Over long cable distances you will have coupling capacitance between signals. Therefore consider some aspects.
The circuitry of the connection is shown in Figure 16.
Figure 16. Circuitry of SPI Over Long Distances
SPI Interface
µC
SPI Interface
AS5050
R
MOSI
MISO
MOSI
C
C
C
R
MISO
C
VSS
SCK
VSS
SCK
R
R
C
C
C
SS/
SS/
C
One aspect is that between MISO and SCK must be separated with VSS. Additionally filter circuitry, reduces the disturbance to a minimum.
Resistors close to the output pins reduce communication noise and increase EMC.
Required resistors on the output pins are between 100 Ohm and 1000 Ohm. Required capacitance is 100pF.
Place the resistors and capacitors as near as possible to the pins.
For additional information on this issue, please refer to the application note AS5055_SPI_APPNote.
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