www.austriamicrosystems.com/AS5130

Revision 1.12

19 - 41

AS5130

Datasheet - Detailed Descr i pti on

7.4 Multi Turn Counter

An 8-bit register is used for counting the magnet’s revolutions. With each zero transition in any direction, the output of a special counter is

incremented or decremented. The initial value after reset is 0 LSB.

The multi turn value is encoded as complement on two. Clockwise rotation gives increasing angle values and positive turn count. Counter

clockwise rotation exhibits decreasing angle values and a negative turn count respectively.

The counter output can be reset by using command 19 – HYST_RST. It is immediately reset by the rising clock edge of this bit. Any zero crossing

between the clock edge and the next counter readout changes the counter value.

7.5 AS5130 Status Indicators

7.5.1 Lock Status Bit

The Lock signal indicates whether the angle information is valid (ADC locked, Lock = high) or invalid (ADC unlocked, Lock = low). To determine

a valid angular signal at best performance, the following indicators should be set:

Lock = 1

0x00h < AGC < 0x2Fh

Note:

The angle signal may also be valid (Lock = 1), when the AGC is out of range (00H or 2FH), but the accuracy of the AS5130 may be

reduced due to the out of range condition of the magnetic field strength.

7.5.2 Magnetic Field Strength Indicators

The AS5130 is not only able to sense the angle of a rotating magnet, it can also measure the magnetic field strength (and hence the vertical

distance) of the magnet. This additional feature can be used for several purposes:

- as a safety feature by constantly monitoring the presence and proper vertical distance of the magnet

- as a state-of-health indicator, e.g. for a power-up self test

- as a pushbutton feature for rotate-and-push types of manual input devices

The magnetic field strength information is available in two forms – Magnetic field strength hardware indicator and Magnetic field strength

software indicator.

determined by the value of the AGC. If the AGC value is <3FH, the CAO output will be high (green range), If the AGC is at its upper limit (3FH),

the CAO output will be low (red range).

contains the 6-bit AGC information. The AGC is an automatic gain control that adjusts the internal signal amplitude obtained from the Hall

elements to a constant level. If the magnetic field is weak, e.g. with a large vertical gap between magnet and IC, with a weak magnet or at

elevated temperatures of the magnet, the AGC value will be high. Likewise, the AGC value will be lower when the magnet is closer to the IC,

when strong magnets are used and at low temperatures.

Bit Code

Decimal Value

01111111

127

---

---

00000011

+3

00000010

+2

00000001

+1

00000000

0

11111111

-1

11111110

-2

11111101

-3

---

---

10000000

-128