AS5045-ASST austriamicrosystems, AS5045-ASST Datasheet - Page 30

• Manufacturer Part Number: AS5045-ASST
• Description: IC ENCODER PROG 12-BIT 16-SSOP
• Manufacturer: austriamicrosystems
• Type: Linear, Rotary Encoder - Programmabler

Specifications of AS5045-ASST

• Sensing Range: 45mT ~ 75mT
• Voltage - Supply: 3 V ~ 3.6 V, 4.5 V ~ 5.5 V
• Current - Supply: 21mA
• Current - Output (max): 4mA
• Output Type: Digital, PWM, 12-Bit Serial
• Features: Programmable
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AS5045-ASSTTR

AS5045
Data Sheet
17.6 Temperature
17.6.1 Magnetic Temperature Coefficient
One of the major benefits of the AS5045 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 AS5045
automatically compensates for the varying magnetic field strength over temperature. The magnet’s temperature drift
does not need to be considered, as the AS5045 operates with magnetic field strengths from ±45…±75mT.
Example:
An 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 AS5045 can compensate for this temperature related field strength change automatically, no user adjustment is
required.
17.7 Accuracy over Temperature
The influence of temperature in the absolute accuracy is very low. While the accuracy is ≤ ±0.5° at room
temperature, it may increase to ≤±0.9° due to increasing noise at high temperatures.
17.7.1 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 cancelled by measuring the complete PWM duty cycle instead
of just the PWM pulse (see 17.5).
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