AS5043

Data Sheet – 10-bit Absolute Synchronous Serial Interface (SSI)

www.austriamicrosystems.com

Revision 1.80

6 – 36

8

10-bit Absolute Synchronous Serial Interface (SSI)

The serial data transmission timing is outlined in Figure 5: if CSn changes to logic low, Data Out (DO) will change from

high impedance (tri-state) to logic high and the read-out sequence will be initiated.

Each subsequent rising CLK edge shifts out one bit of data.

The serial word contains 16 bits, the first 10 bits are the angular information D[9:0], the subsequent 6 bits contain system

information, about the validity of data such as OCF, COF, LIN, Parity and Magnetic Field status (increase / decrease / out

of range) .

Data transmission may be terminated at any time by pulling CSn = high.

8.1

Serial Data Contents

D9:D0

absolute angular position data (MSB is clocked out first).

OCF

(Offset Compensation Finished), logic high indicates that the Offset Compensation Algorithm has finished and data

is valid.

COF

(Cordic Overflow), logic high indicates an out of range error in the CORDIC part. When this bit is set, the data at

D9:D0 is invalid. The absolute output maintains the last valid angular value.

This alarm may be resolved by bringing the magnet within the X-Y-Z tolerance limits.

LIN

(Linearity Alarm), logic high indicates that the input field generates a critical output linearity.

When this bit is set, the data at D9:D0 may still be used, but may contain invalid data. This warning may be resolved by

bringing the magnet within the X-Y-Z tolerance limits.

Data D9:D0 is valid, when the status bits have the following configurations:

Table 2: Status Bit Outputs

OCF

COF

LIN

Mag

INC

Mag

DEC

Parity

0

0

0

1

1

0

0

1

0

even checksum of bits 1:15

MagInc

, (Magnitude Increase) becomes HIGH, when the magnet is pushed towards the IC, thus the magnetic field

strength is increasing.

MagDec,

(Magnitude Decrease) becomes HIGH, when the magnet is pulled away from the IC, thus the magnetic field

strength is decreasing.

Both signals HIGH indicate a magnetic field that is out of the allowed range (see Table 3).

Note: Pin 1 (MagRngn) is a combination of MagInc and MagDec. It is active low via an open drain output and requires an

external pull-up resistor. If the magnetic field is in range, this output is turned off. (logic “high”).

Even Parity

bit for transmission error detection of bits 1…15 (D9…D0, OCF, COF, LIN, MagInc, MagDec)

The absolute angular output is always set to a resolution of 10 bit / 360°. Placing the magnet above the chip, angular

values increase in clockwise direction by default.

Figure 5: Synchronous Serial Interface with Absolute Angular Position Data

Even

PAR

CSn

CLK

DO

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

18

16

COF

LIN

OCF

Ma g

IN C

Ma g

DEC

1

D9

Angular Position Data

Status Bits