AS5046 AB austriamicrosystems, AS5046 AB Datasheet - Page 39

• Manufacturer Part Number: AS5046 AB
• Description: BOARD ADAPTER AS5046
• Manufacturer: austriamicrosystems

Specifications of AS5046 AB

• Sensor Type: Magnetic, Rotary Position
• Sensing Range: 360°
• Interface: Serial
• Voltage - Supply: 9V
• Embedded: No
• Utilized Ic / Part: AS5046
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• Sensitivity: -

AS5046
Data Sheet
21.5 Output Delays
The propagation delay is the delay between the time that the sample is taken until it is available as angular data. This
delay is 96µs in fast mode (pin Mode = high) and 384µs in slow mode (pin Mode = low or open).
The analog output produces no further delay, the output voltage will be updated as soon as it is available. Using the
serial interface for data transmission, an additional delay must be considered, caused by the asynchronous sampling
(0….1/f
21.5.1 Angular Error Caused by Propagation Delay
A rotating magnet will cause an angular error caused by the propagation delay.
This error increases linearly with speed:
Note: since the propagation delay is known, it can be automatically compensated by the control unit processing the
data from the AS5046.
21.6 Internal Timing Tolerance
The AS5046 does not require an external ceramic resonator or quartz. All internal clock timings for the AS5046 are
generated by an on-chip RC oscillator. This oscillator is factory trimmed to ±5% accuracy at room temperature (±10%
over full temperature range). This tolerance influences the ADC sampling rate:
21.6.1 Absolute Output; Serial Interface
A new angular value is updated every
21.7 Temperature
21.7.1 Magnetic Temperature Coefficient
One of the major benefits of the AS5046 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 AS5046
automatically compensates for the varying magnetic field strength over temperature. The magnet’s temperature drift
does not need to be considered, as the AS5046 operates with magnetic field strengths from ±45…±75mT.
Example:
A NdFeB magnet has a field strength of 75mT @ –40°C and a temperature coefficient of -0.12% per Kelvin. The
temperature change is from –40° to +125° = 165K.
The magnetic field change is: 165 x -0.12% = -19.8%, which corresponds to 75mT at –40°C and 60mT at 125°C .
The AS5046 can compensate for this temperature related field strength change automatically, no user adjustment is
required.
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384µs +/- 5% (Mode = 0 or open)
sample
where
96µs +/- 5% (Mode = 1) or
e
sampling
) and the time it takes the external control unit to read and process the angular data from the AS5046.
(deg)
e
rpm = rotating speed [rpm]
prop.delay = propagation delay [seconds]
sampling
=
6
= angular error [°]
∗
rpm
∗
pr
.
delay
Revision 1.12
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