AS5130ATST AMSCO [austriamicrosystems AG], AS5130ATST Datasheet - Page 20

• Manufacturer Part Number: AS5130ATST
• Description: 8 Bit Programmable Magnetic Rotary Encoder with Motion Detection & Multiturn
• Manufacturer: AMSCO [austriamicrosystems AG]

AS5130
Data Sheet - D e t a i l e d D e s c r i p t i o n
Table 13.
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.
AS5130 Status Indicators
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
AGC = >00H and < 2FH
Note: The angle signal may also be valid (Lock = 1), when the AGC is out of range (00H or 2FH), but the accuracy of
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:
The magnetic field strength information is available in two forms – Magnetic field strength hardware indicator and
Magnetic field strength software indicator.
Magnetic Field Strength Hardware Indicator
Pin CAO (#1) will be low, when the magnetic field is too weak. The switching limit is 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).
Magnetic Field Strength Software Indicator
D13:D7 in the serial data that is obtained by command READ ANGLE
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.
The best performance of the AS5130 will be achieved when operating within the AGC range. It will still be operational
outside the AGC range, but with reduced performance especially with a weak magnetic field due to increased noise.
Factors Influencing the AGC Value
In practical use, the AGC value will depend on several factors:
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- 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 AS5130 may be reduced due to the out of range condition of the magnetic field strength.
10000000
Bit Code
11111110
11111101
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Revision 1.00
(see Table 9)
Decimal Value
-128
contains the 6-bit AGC
-2
-3
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