AS5043
Data Sheet – Daisy Chain Mode
10 Daisy Chain Mode
The Daisy Chain Mode allows connection of several AS5043’s in series, while still keeping just one digital input for data
transfer (see “Data IN” in Figure 6 ). This mode is accomplished by connecting the data output (DO; pin 9) to the data
input (PROG; pin 8) of the subsequent device. An RC filter must be implemented between each PROG pin of device n
and DO pin of device n+1, to prevent then encoders to enter the alignment mode, in case of ESD discharge, long cables,
not conform signal levels or shape. Using the values R=100R and C=1nF allow a max. CLK frequency of 1MHz on the
whole chain. The serial data of all connected devices is read from the DO pin of the first device in the chain. The length of
the serial bit stream increases with every connected device, it is
n * (16+1) bits:
e.g. 34 bit for two devices, 51 bit for three devices, etc…
The last data bit of the first device (Parity) is followed by a dummy bit and the first data bit of the second device (D9),
etc… (see Figure 7).
Figure 6: Daisy Chain Hardware Configuration
CSn
CLK
DO
CSn
CLK
DO
CSn
CLK
DO
CSn
CLK
DI
100R
100R
PROG
PROG
PROG
1nF
GND
1nF
GND
GND
MCU
AS5043
AS5043
AS5043
Figure 7: Daisy Chain Data Transfer Timing Diagram
CSn
tCLK FE TCLK/2
1
8
16
D
1
2
3
CLK
Mag Mag Even
INC DEC PAR
DO
OCF COF LIN
D9 D8 D7
D9 D8 D7 D6
D5 D4 D3 D2 D1 D0
tDO
tDO
valid
active
Angular Position Data
Status Bits
Angular Position Data
2nd Device
1st Device
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