AS5043
Data Sheet – Angular Output Tolerances
Figure 23: Example of Linearity Error over 360°
Linearity Error with Centered Magnet [degrees]
0.5
0.4
0.3
0.2
0.1
0
transition noise
Err
max
1
55 109 163 217 271 325 379 433 487 541 595 649 703 757 811 865 919 973
-0.1
-0.2
-0.3
-0.4
-0.5
Err
min
18.3 Transition Noise
Transition noise is defined as the jitter in the transition between two steps.
Due to the nature of the measurement principle (Hall sensors + Preamplifier + ADC), there is always a certain degree of
noise involved.
This transition noise voltage results in an angular transition noise at the outputs. It is specified as 0.06 degrees rms
(1 sigma)*1 in fast mode (pin MODE = high) and 0.03 degrees rms (1 sigma)*1 in slow mode (pin MODE = low or open).
These values are the repeatability of an indicated angle at a given mechanical position.
The transition noise has different implications on the type of output that is used:
absolute output; SSI interface:
The transition noise of the absolute output can be reduced by the user by applying an averaging of readings. An
averaging of 4 readings will reduce the transition noise by 6dB or 50%, e.g. from 0.03°rms to 0.015°rms (1
sigma) in slow mode
analog output:
Ideally, the analog output should have a jitter that is less than one digit. In 360° mode, both fast or slow mode
may be selected for adequate low jitter.
In 180°, 90° or 45° mode, where the step sizes are smaller, slow mode should be selected to reduce the output
jitter.
*1: statistically, 1 sigma represents 68.27% of readings,
3 sigma represents 99.73% of readings.
18.4 High Speed Operation
18.4.1 Sampling Rate
The AS5043 samples the angular value at a rate of 10.42k samples per second (ksps) in fast mode and 2.61ksps in slow
mode.
Consequently, a new reading is performed each 96µs. (fast mode) or 384µs (slow mode).
At a stationary position of the magnet, this sampling rate creates no additional error.
Absolute Mode:
With the given sampling rates, the number of samples (n) per turn for a magnet rotating at high speed can be calculated
by
60
for fast mode
n =
rpm ⋅96μs
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