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AS5045B

Datasheet - Detailed Descr i p ti on

The two pins can 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 8).

8.2 Incremental Mode

The AS5045B has an internal interpolator block. This function is used if the input magnetic field is to fast and a code position is missing. In this

case an interpolation is done.

status of the CSn pin:



CSn = low at power-up: CSn has an internal pull-up resistor and must be externally pulled low (

). If Csn is low at power-up,

the incremental outputs (A, B, Index) will be high until the internal offset compensation is finished. This unique state (A=B=Index = high) can

be used as an indicator for the external controller to shorten the waiting time at power-up. Instead of waiting for the specified maximum

power up-time (0), the controller can start requesting data from the AS5045B as soon as the state (A=B=Index = high) is cleared.



CSn = high or open at power-up: In this mode, the incremental outputs (A, B, Index) will remain at logic high state, until CSn goes low or a

low pulse is applied at CSn. This mode allows intentional disabling of the incremental outputs until, for example the system microcontroller

is ready to receive data.

Figure 6. Incremental Output

The hysteresis trimming is done at the final test (factory trimming) and set to 4 LSB, related to a 12-bit number.

of a rotational direction change, the incremental outputs have a hysteresis of 4 LSB. Regardless of the programmed incremental resolution, the

hysteresis of 4 LSB always corresponds to the highest resolution of 12-bit. In absolute terms, the hysteresis is set to 0.35 degrees for all

resolutions. For constant rotational directions, every magnet position change is indicated at the incremental outputs (see Figure 7). For example,

if the magnet turns clockwise from position “x+3“ to “x+4“, the incremental output would also indicate this position accordingly. A change of the

magnet’s rotational direction back to position “x+3“ means that the incremental output still remains unchanged for the duration of 4 LSB, until

position “x+2“is reached. Following this direction, the incremental outputs will again be updated with every change of the magnet position.

R

ext

5k

Ω

≤

I

B

A

1 LSB

Programmed

Zero Position

ClockWise

3 LSB

Counter ClockWise