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AS5245

Data Sheet - D e t a i l e d D e s c r i p t i o n

8.2.2 Z-axis Range Indication (Push Button Feature, Red/Yellow/Green Indicator)

The AS5245 provides several options of detecting movement and distance of the magnet in the Z-direction. Signal indicators MagINCn and

MagDECn are available both as hardware pins (pins #1 and 2) and as status bits in the serial data stream (see Figure 5). Additionally, an OTP

programming option is available with bit MagCompEn that enables additional features:

In the default state, the status bits MagINC, MagDec and pins MagINCn, MagDECn have the following function:

Note:

Pin 1 (MagINCn) and pin 2 (MagDECn) are active low via. open drain output and require an external pull-up resistor. 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 8).

8.2.3 Incremental Mode

The AS5245 has an internal interpolator block. This function is used if the input magnetic field is too fast and a code position is missing. In this

case an interpolation is done.

With the OTP bits OutputMd0 and OutputMd1 a specific mode can be selected. For the available pre-programmed incremental versions (10bit

and 12bit), these bits are set during test at austriamicrosystems. These settings are permanent and can not be recovered.

A change of the incremental mode (WRITE command) during operation could cause problems. A power-on-reset in between is recommended.

During operation in incremental mode it is recommended setting CSn = High, to disable the SSI-Interface.

Table 8. Magnetic Field Strength Red-Yellow-Green Indicator (OTP option)

Status Bits

Hardware Pins

OPT: Mag CompEn = 1 (Red-Yellow-Green Programming Option)

Mag

INC

Mag

DEC

LIN

Mag

INCn

Mag

DECn

Description

00

0

Off

Off

No distance change

Magnetic input field OK (GREEN range, ~45…75mT)

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0

On

Off

YELLOW range: magnetic field is ~ 25…45mT or ~75…135mT. The AS5245

may still be operated in this range, but with slightly reduced accuracy.

11

1

On

On

RED range: magnetic field is ~<25mT or >~135mT. It is still possible to

operate the AS5245 in the red range, but not recommended.

All other combinations

n/a

n/a

Not available

Table 9. Incremental Resolution

Mode

Description

Output

Md1

Output

Md0

Resolution

DTest1_A

and

DTest2_B

Pulses

Index Width

Default mode

AS5245 function DTEST1_A and

DTEST2_B are not used. The

Mode_Index pin is used for selection of

the decimation rate (low speed/high

speed).

00

10 bit

Incremental

mode

(low DNL)

DTEST1_A and DTEST2_B are used as

A and B signal. In this mode the

Mode_Index Pin is switched from input

to output and will be the Index Pin. The

decimation rate is set to 64 (fast mode)

and cannot be changed from external.

0

1

10

256

1/3

LSB

12 bit

Incremental

mode (high

DNL)

1

0

12

1024

Sync mode

In this mode a control signal is switched

to DTEST1_A and DTEST2_B.

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