ams AS5510 Adapter Board User Manual

ams -AS5510 -Adapter -Board

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General Description

The AS5510 is a linear Hall sensor with 10 bit resolution and I²C interface. It can measure absolute position of lateral movement of a simple 2-pole magnet. The typical arrangement is shown below in (Figure 1). Depending on the magnet size, a lateral stroke of 0.5~2mm can be measured with air gaps around 1.0mm. To conserve power, the AS5510 may be switched to a power down state when it is not used. Figure 1: Linear Position Sensor AS5510 + Magnet

Board Description

The AS5510 adapter board is a simple circuit allowing to test and evaluate the AS5510 linear encoder quickly without having to build a test fixture or PCB. The adapterboard must be attached to a microcontroller via the I²C bus, and supplied with a voltage of 2.5V ~ 3.6V. A simple 2-pole magnet is placed on the top of the encoder. Figure 2: AS5510 adapter board mounting and dimension

• I2C and Power Supply Connector
• I2C Adress selector
  • Open: 56h (default)
  • Closed: 57h
• Mounting holes 4×2.6mm
• AS5510 Linear Position Sensor

Pinout

The AS5510 is available in a 6-pin Chip Scale Package with a ball pitch of 400µm. Figure 2:
Pin Configuration of AS5510 (Top View)

(56h). Close JP1 for (57h).
J1: pin 4| A3| VDD| S| Positive supply pin, 2.5V ~ 3.6V
J1: pin 2| B1| SDA| DI/DO_OD| I²C data I/O, 20mA driving capability
J1: pin 1| B2| SCL| DI| I²C clock
n.c.| B3| Test| DIO| Test pin, connected to VSS

Table 1: Pin Description

• DO_OD … digital output open drain
• DI … digital input
• DIO … digital input/output
• S … supply pin

Mounting the AS5510 Adapter board

The AS5510-AB can be fixed to an existing mechanical system by its four mounting holes. A simple 2-poles magnet placed over or under the IC can be used.

Figure 3:
AS5510 adapter board mounting and dimension

The maximum horizontal travel amplitude depends on the magnet shape and size and magnetic strength (magnet material and airgap). In order to measure a mechanical movement with a linear response, the magnetic field shape at a fixed airgap must be like on Figure 4:. The linear range width of the magnetic field between North and South poles determines the maximum travel size of the magnet. The minimum (-Bmax) and maximum (+Bmax) magnetic field values of the linear range must be lower or equal to one of the four sensitivities available on the AS5510 (register 0Bh): Sensitivity = ± 50mT, ± 25mT, ±18.5mT, ±12.5mT The 10-bit output register D[9..0] OUTPUT = Field(mT) * (511/Sensitivity) + 511.

Figure 4:

**Magnet requirement

**

Example 1:
This is the ideal case: the linear range of the magnet is ±25mT, which fits to the ±25mT sensitivity setting of the AS5510. The resolution of displacement vs. output value is optimal. Max. Travel Distance TDmax = ±1mm (Xmax = 1mm) Sensitivity = ±25mT (Register 0Bh 01h)

• Bmax = 25mT
• X = -1mm (= -Xmax) Field(mT) = -25mT OUTPUT = 0
• X = 0mm Field(mT) = 0mT OUTPUT = 511
• X = +1mm (= +Xmax) Field(mT) = +25mT OUTPUT = 1023

Dynamic range of OUTPUT over ±1mm: DELTA = 1023 – 0 = 1023 LSB Resolution = TDmax / DELTA = 2mm / 1024 = 1.95μm/LSB

Example 2:
Using the same settings on the AS5510, the linear range of the magnet over the same displacement of ±1mm is now ±20mT instead of ±25mT due to a higher airgap or a weaker magnet. In that case the resolution of displacement vs. output value is lower. Max. Travel Distance TDmax = ±1mm (Xmax = 1mm): unchanged Sensitivity = ±25mT (Register 0Bh  01h) : unchanged

• Bmax = 20mT
• X = -1mm (= -Xmax) Field(mT) = -20mT OUTPUT = 102
• X = 0mm Field(mT) = 0mT OUTPUT = 511
• X = +1mm (= +Xmax) Field(mT) = +20mT OUTPUT = 920

Dynamic range of OUTPUT over ±1mm: DELTA = 920 – 102 = 818 LSB Resolution = TDmax / DELTA = 2mm / 818 = 2.44μm/LSB In order to keep the best resolution of the system, it is recommended to adapt the sensitivity as close as the Bmax of the magnet, with Bmax < Sensitivity to avoid the saturation of the output value. If a magnet holder is used, it must be made of a non-ferromagnetic material in order to keep the maximum magnetic field strength and maximum linearity. Materials as brass, copper, aluminium, stainless steel are the best choices to make this part.

Connecting the AS5510-AB

Two wires (I²C) only are required for communication with the host MCU. Pull-up resistors are needed on both SCL and SDA line. The value depends on the length of the wires, and the amount of slaves on the same I²C line. The power supply delivering between 2.7V ~ 3.6V is connected to the adapter board and the pull- up resistors. A second AS5510 adapterboard (optional) can be connected on the same line. In that case, the I²C address must be changed by closing JP1 with a wire.

Figure 5:
Typical connection to a host MCU (2nd adapter board is optional)

Software example

After powering up the system, a delay of >1.5ms must be performed before the first I²C Read/Write command with the AS5510. The initialization after power up is optional. It consists of:

• Sensitivity configuration (Register 0Bh)
• Magnet polarity (Register 02h bit 1)
• Slow or Fast mode (Register 02h bit 3)
• Power Down mode (Register 02h bit 0)

Reading the magnetic field value is straight forward. The following source code reads the 10-bit magnetic field value, and converts to the magnetic field strength in mT (millitesla). Example: Sensitivity configured to +-50mT range (97.66mT/LSB); Polarity = 0; default setting:

• D9..0 value = 0 means -50mT on the hall sensor.
• D9..0 value = 511 means 0mT on the hall sensor (no magnetic field, or no magnet).
• D9..0 value = 1023 means +50mT on the hall sensor.

Schematic and Layout

Figure 6:
AS5510-AB Schematic

Figure 7:
AS5510-AB Layout

Ordering Information

Table 2:
Ordering Information

package

Copyright

Copyright ams AG, Tobelbader Strasse 30, 8141 Unterpremstätten, Austria- Europe. Trademarks Registered. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.

Disclaimer

Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein. AMS AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high- reliability applications, such as military, medical life-support or life- sustaining equipment are specifically not recommended without additional processing by ams AG for each application. This Product is provided by ams “AS IS” and any express or implied warranties, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed. AMS AG shall not be liable to the recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business, or indirect, special, incidental, or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to the recipient or any third party shall arise or flow out of ams AG rendering of technical or other services.

Contact Information

Headquarters ams AG Tobelbader Strasse 30 8141 Unterpremstaetten Austria T. +43 (0) 3136 500 0 For Sales Offices, Distributors and Representatives, please visit: http://www.ams.com/contact

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