AS5030 8-bit Programmable Magnetic Rotary Encoder

Rev. 1.8

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Page 9 of 33

4.12 Connecting the AS5030

The following examples show various ways to connect the AS5030 to an external controller:

4.13 Serial 3-Wire R/W Connection

In this mode, the AS5030 is connected to the external

controller via three signals:

Chip Select (CS), Clock (CLK) inputs and bi-directional DIO

(Data In/Out) output.

The controller sends commands over the DIO pin at the

beginning of each data transmission sequence, such as

reading the angle or putting the AS5030 in and out of the

reduced power modes.

A pull-down resistor (as shown in 4.14) is not required.

C1 and C2 are hardware configuration inputs. C1 must always

be connected to VSS, C2 selects 3-wire mode (C2 = low) or 2-

wire mode (C2 = high)

Figure 4: SSI read/write serial data transmission

Figure 5: Timing diagram in 3-wire SSI R/W mode (timing values in 4.11: General Data Transmission Timings)

Serial bit sequence (16bit read/write):

Write Command

Read/Write Data

C4

C3

C2

C1

C0

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

4.14 Serial 3-Wire Read-only Connection

If the AS5030 is only used to provide the angular data (no

power down or OTP access) this simplified connection is

possible. The Chip Select (CS) and Clock (CLK) connection is

the same as in the R/W mode (see 4.13), but only a digital

input pin (not an I/O pin) is required for the DIO connection.

As the first 5 bits of the data transmission are command bits

sent to the AS5030, both the microcontroller and the AS5030

are configured as digital inputs during this phase. Therefore, a

pull-down resistor must be added to make sure that the

AS5030 reads “00000” as the first 5 bits which sets the

Read_Angle command.

Note: all further application examples are shown in R/W

mode, however read-only mode is also possible unless

otherwise noted.

Figure 6: SSI read-only serial data transmission

AS5030

Micro

Controller

100n

CS

CLK

DIO

+5V

VDD

VSS

VSS

C2

VDD

VDD

13

11

10

12

15

C1

VSS

3

14

I/O

Output

Output

AS5030

Micro

Controller

100n

CS

CLK

DIO

+5V

VDD

VSS

VSS

C2

VDD

VDD

13

11

10

12

15

C1

VSS

3

14

Input

10k...

100k

Output

Output