AS5046-ASST austriamicrosystems, AS5046-ASST Datasheet - Page 36

• Manufacturer Part Number: AS5046-ASST
• Description: IC ENCODER PROG 12-BIT 16-SSOP
• Manufacturer: austriamicrosystems
• Type: Linear, Rotary Encoder - Programmabler

Specifications of AS5046-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: Analog, Ratiometric
• Features: Programmable
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AS5046-ASSTTR

AS5046
Data Sheet
20 Failure Diagnostics
The AS5046 also offers several diagnostic and failure detection features:
20.1 Magnetic Field Strength Diagnosis
By software: the MagInc and MagDec status bits will both be high when the magnetic field is out of range.
By hardware: Pin #1 (MagRngn) is a logical NAND-ed combination of the MagInc and MagDec status bits. It is an
open-drain output and will be turned on (= low with external pull-up resistor) when the magnetic field is out of range.
By hardware: Pin #12 (Vout) is the analog output of the DAC and OP-Amp. The analog output will be 0V, when the
magnetic field is out of range (all analog modes).
20.2 Power Supply Failure Detection
By software: If the power supply to the AS5046 is interrupted, the digital data read by the serial interface will be all
“0”s. Data is only valid, when bit OCF is high, hence a data stream with all “0”s is invalid. To ensure adequate low
levels in the failure case, a pull-down resistor (~10kΩ) should be added between pin DO and VSS at the receiving
side.
By hardware: The MagRngn pin is an open drain output and requires an external pull-up resistor. In normal
operation, this pin is high ohmic and the output is high. In a failure case, either when the magnetic field is out of range
or the power supply is missing, this output will become low. To ensure an adequate low level in case of a broken
power supply to the AS5046, the pull-up resistor (~10kΩ) must be connected to the positive supply at pin 16 (VDD5V).
21 Angular Output Tolerances
21.1 Accuracy; Digital Outputs
Accuracy is defined as the error between measured angle and actual angle. It is influenced by several factors:
As a sum of all these errors, the accuracy with centered magnet = (Err
degrees @ 25°C (see Figure 26).
Misalignment of the magnet further reduces the accuracy. Figure 25 shows an example of a 3D-graph displaying non-
linearity over XY-misalignment. The center of the square XY-area corresponds to a centered magnet (see dot in the
center of the graph). The X- and Y- axis extends to a misalignment of ±1mm in both directions. The total misalignment
area of the graph covers a square of 2x2 mm (79x79mil) with a step size of 100µm.
For each misalignment step, the measurement as shown in Figure 26 is repeated and the accuracy (Err
(e.g. 0.25° in Figure 26) is entered as the Z-axis in the 3D-graph.
www.austriamicrosystems.com
the non-linearity of the analog-digital converters,
internal gain and mismatch errors,
non-linearity due to misalignment of the magnet
Revision 1.12
max
– Err
min
)/2 is specified as better than ±0.5
max
– Err
36 – 42
min
)/2