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AS5145

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

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).

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 9).

8.1.2 Incremental Mode

The AS5145 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.

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 9. Magnetic Field Strength Red-Yellow-Green Indicator

Status Bits

Hardware Pins

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

Mac

INC

Mag DEC

LIN

Mac INCn Mag DECn

Description

000

Off

Off

No distance change

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

110

On

Off

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

AS5145 may still be operated in this range, but with slightly reduced

accuracy.

111

On

On

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

operate the AS5145 in the red range, but not recommended.

All other combinations

n/a

n/a

Not available

Table 10. Incremental Resolution

Mode

Description

Output

Md1

Output

Md0

Resolution

DTest1_A

and

DTest2_B

Pulses

Index Width

Default mode

AS5145 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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