AS5030 8-bit Programmable Magnetic Rotary Encoder

Rev. 1.8

www.austriamicrosystems.com

Page 11 of 33

4.16 Serial 2-wire Continuous Readout

method to ensure synchronization, as each timeout of CLK resets the serial interface.

However, it is not mandatory to apply a timeout of CLK and consequently synchronization after each reading. It is also possible

to read several consecutive angle values without synchronization by simply continuing the CLK pulses without timeout after the

This is the fastest way to read multiple angle values, as there is no timeout period between the readings. It is still possible to

reading, etc…)

CMD4

CLK

CS

DIO read

t0

t6

command phase

data phase

DIO write

t1

1

2

3

4

567

22

DX

8

CMD2

CMD3

CMD1

CMD0

D15

D14

D0

t5

23

24

25

CMD4

CMD2

CMD3

1st reading

2nd reading

command phase

Figure 10: Timing diagram in 2-wire SSI continuous readout

4.17 Serial 2-Wire Differential SSI Connection

With the addition of a RS-422 / RS-

485 transceiver, a fully differential

data transmission, according to the

21-bit SSI interface standard is

possible. To be compatible with this

standard, the CLK signal must be

inverted. This is done by reversing the

Data+

and

Data-

lines

of

the

transceivers.

Note: This type of transmission is

read-only.

Figure 11: 2-wire SSI read-only mode

Figure 12: Timing diagram in 2-wire readonly mode (differential transmission)

SSI read-only serial bit sequence (21bit read):

Read

D20

D19

D18

D17

D16

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

AGC

Angle

0

0

0

0

0

C2

lock

D5

D4

D3

D2

D1

D0

D7

D6

D5

D4

D3

D2

D1

D0

AS5030

Micro

Controller

100n

CS

CLK

DIO

+5V

VDD

VSS

VSS

C2

VDD

VDD

13

11

10

12

15

C1

VSS

3

14

Input

Output

DX

9

CLK

DI

D+

D-

D+

D-

MAX 3081 or similar

D+

D-

D-

D+