AS5040-ASST View Datasheet(PDF) - austriamicrosystems AG
Part Name
Description
MFG CO.
'AS5040-ASST' PDF : 61 Pages View PDF
AS5040 − Angular Output Tolerances
Temperature
Magnetic Temperature Coefficient
One of the major benefits of the AS5040 compared to linear Hall
sensors is that it is much less sensitive to temperature. While
linear Hall sensors require a compensation of the magnet’s
temperature coefficients, the AS5040 automatically
compensates for the varying magnetic field strength over
temperature. The magnet’s temperature drift does not need to
be considered, as the AS5040 operates with magnetic field
strengths from ±45mT to ±75mT.
Example:
A NdFeB magnet has a field strength of 75mT @ -40ºC and a
temperature coefficient of -0.12% per Kelvin.
The temperature change is from -40º to +125º = 165K.
The magnetic field change is: 165 x -0.12% = -19.8%, which
corresponds to 75mT at -40ºC and 60mT at 125ºC.
The AS5040 can compensate for this temperature related field
strength change automatically, no user adjustment is required.
Accuracy Over Temperature
The influence of temperature in the absolute accuracy is very
low. While the accuracy is ≤ ±0.5º at room temperature, it may
increase to ≤ ±0.9º due to increasing noise at high
temperatures.
Timing Tolerance Over Temperature
The internal RC oscillator is factory trimmed to ±5%. Over
temperature, this tolerance may increase to ±10%. Generally,
the timing tolerance has no influence in the accuracy or
resolution of the system, as it is used mainly for internal clock
generation.
The only concern to the user is the width of the PWM output
pulse, which relates directly to the timing tolerance of the
internal oscillator. This influence, however, can be canceled by
measuring the complete PWM duty cycle (see Internal Timing
Tolerance).
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ams Datasheet
[v2-12] 2017-Jun-20
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