Revision 1.0, 29.January 2009
Page 1 of 12
www.austriamicrosystems.com
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General Overview
The AS5X40 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360°.
It is a system-on-chip, combining integrated Hall elements, analog front end and digital signal processing in a single
device.
To measure the angle, only a simple two-pole magnet, rotating over the center of the chip, is required. The magnet may
be placed above or below the IC.
The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 0.35°
= 1024 positions per revolution (AS5X40). This digital data is available as a serial bit stream and as a PWM signal.
Furthermore, a user-programmable incremental output is available, making the chip suitable for replacement of various
optical encoders.
An internal voltage regulator allows the AS5X40 to operate at either 3.3 V or 5 V supplies.
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The AS5X40 Demoboard
The AS5X40 demoboard is a complete rotary encoder system with built-in microcontroller, USB interface, graphical
LCD display, incremental indicators, commutation indicators and PWM output LED.
The board is USB powered or externally supplied with a 9V battery for standalone operation.
Figure 1: AS5X40 Demoboard hardwar e with mounted magnet knob
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Operating the AS5X40 Demoboard
The AS5X40 demoboard can be used in several ways:
•
As standalone unit supplied by a 9V battery
Connect a 9V battery to the battery connector on the top right side of the board. No other connections are required.
•
As standalone unit supplied by an USB port
Connect the demoboard to a PC using a USB/USB cable (included in demoboard shipment). The board is supplied by
the 5V supply of the USB port. No other connections are required.
•
As input device for the AS5000 Programmer GUI software
This configuration uses the same USB hardware connection as above, but additionally the AS5000 Programmer GUI
software is running. The LCD display will be turned off and the Angle/Multiturn/AGC will be displayed on the PC screen.
Some extra features as pole pair, zero position or AGC programming can be achieved. The parameters will not be
permanently programmed. All the parameters will be lost when the demoboard is shut down. For a permanent device
programming, the “AS5000 Programmer” hardware should be used.
AS5040 / AS5140 Demoboard
OPERATION MANUAL
Application note
9V battery connector
(standalone only)
USB cable to the PC
SiLabs C8051F320
microcontroller
Onboard AS5x40 output signals connector and indicators:
Quadrature A/B
and Index output signal
J6: External Encoder
SSI Connector
External (left) – Onboard
(right) encoder selection
switch SW1
Knob with D5x2.5mm
diametral magnet,
2mm over the AS5X40
LCD display (for standalone mode)
