AS5134-ASSU austriamicrosystems, AS5134-ASSU Datasheet - Page 23

• Manufacturer Part Number: AS5134-ASSU
• Description: ENCODER, MAGNETIC, ROTARY, 8BIT, 20SSOP
• Manufacturer: austriamicrosystems

Specifications of AS5134-ASSU

• Brief Features: 9-Bit Multiturn Counter, User Programmable Zero Position And Sensitivity
• Supply Voltage Range: 4.5V To 5.5V
• Operating Temperature Range: -40°C To +140°C
• Digital Ic Case: RoHS Compliant
• Ic Function: Programmable High Speed Magnetic Rotary Encoder
• Rohs Compliant: Yes

AS5134
Data Sheet - D e t a i l e d D e s c r i p t i o n
OTP Sensitivity Adjustment
To obtain best performance and tolerance against temperature or vertical distance fluctuations, the AGC value at
normal operating temperature should be in the middle between minimum and maximum, hence it should be around
100000 (20H). To facilitate the “vertical centering” of the magnet+IC assembly, the sensitivity of the AS5134 can be
adjusted in the OTP register in 4 steps. A sensitivity adjustment is recommended, when the AGC value at normal
operation is close to its lower limit (around 00H). The default sensitivity setting is 00
will increase the sensitivity
Multi Turn Counter
A 9-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 20 – SET MT Counter. 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.
High Speed Operation
The AS5134 is using a fast tracking ADC (TADC) to determine the angle of the magnet. The TADC is tracking the
angle of the magnet with cycle time of 2µs (typ. 1.4). Once the TADC is synchronized with the angle, it sets the LOCK
bit in the status register. In worst case, usually at start-up, the TADC requires up to 255 steps (255 * 2µs = 510µs) to
lock. Once it is locked, it requires only one cycle [2µs (typ. 1.4)] to track the moving magnet. The AS5134 can operate
in locked mode at rotational speeds up to min. 25.000 rpm.
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they can maintain to operate the AS5134 within the AGC range. Every magnet has a temperature dependence of
the magnetic field strength. The temperature coefficient of a magnet depends on the used material. At elevated
temperatures, the magnetic field strength of a magnet is reduced, resulting in an increase of the AGC value. At low
temperatures, the magnetic field strength is increased, resulting in a decrease of the AGC value. The variation of
magnetic field strength over temperature is automatically compensated by the AGC.
100000000
011111111
00000011
00000010
00000001
00000000
10000000
Bit Code
11111101
01111111
11111110
11111111
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(see Table
3).
Revision 1.8
Decimal Value
-128
-255
H
256
127
+3
+2
+1
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-1
-2
-3
0
= low sensitivity. Any value >00
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H