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Data Sheet - D e t a i l e d D e s c r i p t i o n
Figure 5. Synchronous Serial Interface with Absolute Angular Position Data
D9:D0 – Absolute angular position data (MSB is clocked out first).
OCF – (Offset Compensation Finished). Logic high indicates the finished Offset Compensation Algorithm. For fast startup, this bit may be polled
by the external microcontroller. As soon as this bit is set, the AS5140H has completed the startup and the data is valid (see Table 17).
COF – (Cordic Overflow). Logic high indicates an out of range error in the CORDIC part. When this bit is set, the data at D9:D0 is invalid. The
absolute output maintains the last valid angular value. This alarm may be resolved by bringing the magnet within the X-Y-Z tolerance limits.
LIN – (Linearity Alarm). Logic high indicates that the input field generates a critical output linearity. When this bit is set, the data at D9:D0 may still
be used, but can contain invalid data. This warning may be resolved by bringing the magnet within the X-Y-Z tolerance limits.
MagINCn – (Magnitude Increase) becomes HIGH, when the magnet is pushed towards the IC, thus increasing the magnetic field strength.
MagDECn – (Magnitude Decrease) becomes HIGH, when the magnet is pulled away from the IC, thus decreasing the magnetic field strength.
Signal “HIGH” for both MagINCn and MagDECn indicate a magnetic field that is out of the allowed range (see Table 16).
Pins 1 and 2 (MagINCn, MagDECn) are open drain outputs and require external pull-up resistors. If the magnetic field is in range, both
outputs are turned off.
The two pins may also be combined with a single pull-up resistor. In this case, the signal is high when the magnetic field is in range. It is low in all
other cases (see Table 16).
Even Parity – A bit for transmission error detection of bits 1to 15 (D9 to D0, OCF, COF, LIN, MagINCn, MagDECn).
The absolute angular output is always set to a resolution of 10 bit. Placing the magnet above the chip, angular values increase in clockwise
direction by default. Data D9:D0 is valid, when the status bits have the following configurations:
Table 16. Magnetic Magnitude Variation Indicator
No distance change
Magnetic Input Field OK (in range)
Distance increase: Pull-function. This state is dynamic, it is only active while the magnet
is moving away from the chip in Z-axis.
Distance decrease: Push- function. This state is dynamic, it is only active while the
magnet is moving towards the chip in Z.-axis.
Magnetic Input Field invalid – out of range: Too large, Too small (missing magnet).
Table 17. Status Bit Outputs
even checksum of bits 1:15
Angular Position Data
OCF COF LIN