www.ams.com

Revision 1.0

12 - 33

AS5045B

Datasheet - Detailed Descr i p ti on

If CSn changes to logic low, Data Out (DO) will change from high impedance (tri-state) to logic high and the read-out will be initiated.





Each subsequent rising CLK edge shifts out one bit of data.



The serial word contains 18 bits, the first 12 bits are the angular information D[11:0], the subsequent 6 bits contain system information,

about the validity of data such as OCF, COF, LIN, Parity and Magnetic Field status (increase/decrease).



Data Content

D11:D0 absolute angular position data (MSB is clocked out first)

OCF (Offset Compensation Finished), logic high indicates the finished Offset Compensation Algorithm

COF (Cordic Overflow), logic high indicates an out of range error in the CORDIC part. When this bit is set, the data at D11:D0 is invalid. The

absolute output maintains the last valid angular value.

This alarm can 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 D11:D0 can still be used, but can contain invalid data. This warning can be resolved by bringing the magnet within

the X-Y-Z tolerance limits.

Even Parity bit for transmission error detection of bits 1…17 (D11…D0, OCF, COF, LIN, MagINC, MagDEC)

Placing the magnet above the chip, angular values increase in clockwise direction by default.

Data D11:D0 is valid, when the status bits have the following configurations:

Note:

MagInc=MagDec=1 is only recommended in YELLOW mode (see Table 8)

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.

Table 7. Status Bit Outputs

OCF

COF

LIN

Mag INC

Mag DEC

Parity

10

0

00

Even checksum of bits

1:15

01

10

11

Table 8. Magnetic Field Strength Red-Yellow-Green Indicator

Status Bits

Hardware Pins

OTP: 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

AS5045B can 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 AS5045B in the red range, but not recommended.

All other combinations

n/a

n/a

Not available