AS5171 datasheet(24/42 Pages) AMSCO

24 / 42 page

Page 24

ams Datasheet

Document Feedback

[v1-01] 2016-Feb-17

AS5171 − Register Description

Linearization

The system linearity can be improved within the desired range

by determining the linearization parameters XLIN1,XLIN2,

YLIN1 and YLIN2 for the linearization function. These four

parameters can be automatically calculated by the dedicated

programmer. The programmer needs a certain number of

samples to compare to the values provided by an absolute

reference system. The optimum number of samples is 32, but it

is also possible to linearize the output characteristic with less

points. Further information on request.

Diagnostic and Functional Safety

AS5171 can be used in safety critical applications. For this

reason, AS5171 is developed as SEooC (Safety element out of

context) according the ISO26262, which assumed safety goals

and assumed ASIL level.

The assumption of use (AoU) and the robust embedded

self-diagnostic, to achieve a high ASIL level in the application,

are described in the AS5171 safety manual.

For additional information regarding the ISO26262 flow at ams

and the SEooC relevant documents (e.g. FMEDA, safety manual,)

please contact the ams technical support for magnetic position

sensors.

Figure 31:

Diagnostic Table

Safety Mechanism

Recoverable

Safe State

SM1

Watchdog failure

No, if a watchdog error is detected, the

sensor provides the error information

till a sensor reset happens

Output is going into HIZ -->

failure band (depending on

output resistor)

SM2

Offset compensation

not complete

Yes, if the offset is below the specified

threshold, sensor recovers the output

Output is forced in failure band.

Depending on FBS setting

SM3

CORDIC overflow

Yes, if the magnetic input field is below

the specified threshold, sensor

recovers the output

Output is forced in failure band.

Depending on FBS setting

SM4

Magnetic input field

too high/too low

Yes, if the magnetic field is inside the

specific range, after the recovery time

the sensor leave the failure

Output is forced in failure band.

Depending on FBS setting

SM5

Vreg undervoltage

Yes

Hi-z: Failure band related to the

out load

SM6

Reverse polarity

Yes, if reverse polarity issue is solved.

No direct safety mechanism, it’s a

protection!

Hi-z: Failure band related to the

out load

SM7

VDD overvoltage

Yes, if the VDD is below the specified

threshold.

Hi-z: Failure band related to the

out load

AS5171 Datasheet(PDF) 24 Page - ams AG

AS5171 Datasheet(HTML) 24 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Datasheet Download

Link URL