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AS5048A/AS5048B

Magnetic Rotary Encoder

14-bit Angular Position Sensor

Datasheet

6

Application Information

6.1

Programming of the AS5048

6.1.1

Programming of the zero position

The absolute angle position can be permanent programmed over the interface. This could be useful for random placement of

the magnet on the rotation axis. A readout at the mechanical zero position can be performed and written back into the IC.

With permanent programming the position is non-reversible stored in the IC. This programming can be performed only once.

To simplify the calculation of the zero position it is only needed to write the value in the IC which was read out before from

the angle register.

6.1.2

Programming sequence with verification

To program the zero position is needed to perform following sequence:

1.

Read angle information

2.

Set the Programming Enable bit in the OTP control register

3.

Write previous read angle position into OTP zero position register

4.

Read back for verification the zero position register data

5.

Set the Burn bit to start the automatic programming procedure

6.

Read angle information (equals to 0)

7.

Set the Verify bit to load the OTP data again into the internal registers with modified threshold comparator levels

8.

Read angle information (equals to 0)

The programming can either be performed in 5V operation using the internal LDO, or in 3V operation but using a minimum

supply voltage of 3.3V. In case of 3V operation, also a 10uF capacitor is required on the VDD3 pin.

6.2

Diagnostic functions of the AS5048

The AS5048 provides diagnostics functions of the IC and also diagnostic functions of the magnetic input field

Following diagnostic flags are available:

See Table 11 register address x3FFD (AS5048A) or Table 16 register address 251 dec (AS5048B)

OCF

(Offset Compensation Finished), logic high indicates the finished Offset Compensation Algorithm. After power up the

flag remains always to logic high.

COF

(Cordic Overflow), logic high indicates an out of range error in the CORDIC part. When this bit is set, the angle and

magnitude data is invalid. The absolute output maintains the last valid angular value.

COMP low

, indicates a weak magnetic field. It is recommended to monitor in addition the magnitude value.

COMP high

, indicated a high magnetic field. It is recommended to monitor the magnitude value.