Page 1
Key Features
6-BIT MAGNETIC
ANGULAR POSITION ENCODER
WITH SERIAL INTERFACE
❑❑❑❑
Up to 64 positions within 360
❑❑❑❑
Non contact switching
❑❑❑❑
Simple magnet as rotary encoder
❑❑❑❑
Zero position programmable (independent of
°
magnet orientation)
❑❑❑❑
Synchronous Serial Interface (SSI)
❑❑❑❑
Cascading is possible
❑❑❑❑
Chip Select Input
❑❑❑❑
Small 8-Pin SOIC (SMT) Package
❑❑❑❑
Temperature Range: -40°C ...+85°C
General Description
The device provides the absolute angul ar position of a simple magnet that is placed under or
Ordering Information
Part Number Package
AS5020 SOIC 8
AS5020T SOIC8 Tape and Reel
above the device’s surface. The device includes the Hall Sensor Array, signal conditioning and
post processing needed to generate a 6-bit binary code. The binary code can be easily
accessed by a Synchronous Serial Interface (SSI). The angle between the device and the
magnetic polarisation axis is exactly represented by one of 64 sectors (of 5.625° each) in the
full 360° range. Zero-Position Programming allows one time programming of a specific zero
position between the device and the magnet. The initial zero position is shown below.
48
56
40
0... initial
N
S
8
α
12
16
24
32
Functional Block Diagram
4mm
Rev. n/c Page 1/11 Feb 2001
Page 2
6-Bit Magnetic Position Encoder
AS5020
Pin Description
Pin # Symbol Type Description
–Data Sheet Rev.1.0
1
DATA
DO DATA
Output of the SSI.
If PD/CS=0, the measured angle data (6bit value) is serially
shifted out over this pin by the CLK, starting with the MSB. A
NVR Bit and a Parity bit are added. (NVR=1 indicates a Non-
V
alid Range of the magnetic field.) Even Parity is given.
2
3
4
V
DD
V
SS
PROG
AI
AI
DI
Positive Supply Voltage.
Negative Supply Voltage (GND).
PROG
ramming Input.
This pin is used to program the zero position into a non-volatile
memory (OTP). The programmed value is subtracted from the
actual measured angle.
5
N.C.
AI
N
ot Connected during operation. This pin is used for testing
purposes.
6
N.C.
AI
N
ot Connected during operation. This pin is used for testing
purposes.
7
PD/CS
DI
P
ower Down Input, Disable or Chip Select (active low).
PD/CS=0 activates the device and enables the measurement.
PD/CS=1 sets the device in power save mode and puts the
DATA pin in high impedance (highZ) state.
8
CLK
DI
CLOCK
Input of the SSI.
This pin is used to serially clock out the measured angle data at
Pin 7 (DATA).
DI: Digital Input AI: Analogue Input
DO: Digital Output OTP: One Time Programmable
MSB: Most Significant Bit
LSB: Least Signifi c ant Bit
Note: The pi ns 5 and 6 must not be connected!
Pin Conf iguration
DATA CLK
VDD PD/CS
PROG N.C.
VSS N.C.
Rev. n/c Page 2/11 Feb 2001
Page 3
6-Bit Magnetic Position Encoder
AS5020
Functional Description
Measurement Principle
A hall sensor array is used to convert the magnetic field distri buti on above the chip surface i nto
–Data Sheet Rev.1.0
a binary code.
Measurement is enabled by PD/CS=0. After each measurement a 6-bit value is latched, with
the first falling edge of the CLK, into an output shift register.
The measured data is accessible via a Synchronous Serial Interface (SSI) by any µController
System.
Ratiometric measurement techniques together with hall sensor conditioning circuitry allow
robust tolerance to magnet misalignment.
Permanent Encoder Magnet
A simple two-pole magnet, e.g. a standard cylindrical permanent magnet that is diametric
magnetised, is needed.
3mm
S
B/mT
30
N
S
Magnetic Field strength of at least ±30mTp is required at the package surface.
-30
180° 360°
α
α/°
N
Standard magnet materials like rare earth AlNiCo / SmCo5 or NdFeB are recommended.
Please enquire for distributor references.
Rev. n/c Page 3/11 Feb 2001
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6-Bit Magnetic Position Encoder
AS5020
Measurement Modes
Two measurement modes can be selected by programming:
–Data Sheet Rev.1.0
1) Single Read Out Mode (default)
2) Continuous Read Out Mode (OTP option)
Chip Select must be active low (PD/CS=0) to enable measurement and bring the output DATA
out of high impedance state.
After a minimum measurement period, the first falli ng edge of CLK latches the actual measured
angular value. The following rising edges shift the data bits out of the DATA pin, beginning with
the most significant bit. An NVR bit and even parity bit are added to the 6 bit angular value. The
NVR bit indicates a non-valid range given by bad magnet positioning.
PD/CS
12 789
CLK
D5
DATA
Latch
actual value
In Single Read Out Mode the start of a new measurement has to be ini ti ated with a short pul se
D4 D0 NVR Parity
(MSB)
Figure 1 SSI read out
Reset not necessary in
Continuos Mode
Next
value
D5
(MSB)
at PD/CS of at least 1 clockcycle. The following falling edge of CLK latches a new measured
value.
If the OTP option Continuous Read Out Mode is chosen, repeated angle measurement is
enabled by PD/CS=0. After each read out sequence the output shift register is automatically
refreshed. Fast transmission of the angular data can be performed without pulsing PD/CS.
Daisy Chain Configuration
In Singe Read Out mode, cascading allows Daisy Chain structures to minimise the
interconnection lines. Connecting DATA with PROG of the cascaded Sensor (see Fig. 2) allo ws
the read out of n sensors with the use of only three wires. The measurement data is shifted in
this configuration through the devices
After n x 9 clock cycles each value of n sensors is vi sible at pin DATA of the first sensor device.
A new measurement can be started with the falling edge of CLK after a power down pulse at
PD/CS.
n12
µµµµC
CLK
Power Down
Data In
AS5020
PROG DATA
CLK PD/CS
AS5020
PROG DATA
CLK PD/CS
AS5020
PROG DATA
CLK PD/CS
Figure 2 Typical Daisy Chain Configuration
Rev. n/c Page 4/11 Feb 2001
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6-Bit Magnetic Position Encoder
P
AS5020
–Data Sheet Rev.1.0
D/CS
12 789
CLK
D4 D0
D5 NVR Parity D5 D4 D0 NVR Pari ty D5
ATA
Latch
actual value
angle 1 angle 2 angle n
Figure 3 Daisy Chain read out
Zero Position P r ogr am m in g
A simple single pin programming allows changing the initial zero posi tion. It is easy to program
Next
value
permanently a new zero-reference into the internal OTP (one time programmable) ROM. This
allows a fast and economic magnet placement since the intrinsic orientation is not important.
Single Pin Programming is provided via the PROG pin. Fig.4 shows the typical programming
sequence needed for fixing the new zero position.
Zero Position P r ogr am m in g S equ en ce
Before calibration, the new zero position must be adjusted in measurement mode (PD/CS=0).
The rising edge of PD/CS gets the actual position and stores it internally for the permanent
programming. A high level at the PROG Pin during power-down (PD/CS=1) with a minimum
duration of 300
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s
select the latched position information and zap the reference value into the OTP ROM.
Continuous Read Out Mode Selection
An optional 9th pulse after the initialisati on pulse, the dummy pulse, and the 6 data pulses can
be used to set Continuous Read Out Mode (see Fig.4).
PROG [V]
8
t
ProgEN
Programming
0
Calibration Position
Latched
Enable
Initialisation
1234
Dummy
Bit 0 Bit 1 Bit 3Bit 2
CS
Note: Daisy Chai n c onfigurat ion is not possible in Continuous Read Out Mode.
Figure 4 Programming s equenc e
Zero Position Programming
5678
Optional
Bit 5Bit 4
Measurement
Cont.
Mode
Enable
t
Rev. n/c Page 5/11 Feb 2001
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6-Bit Magnetic Position Encoder
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AS5020
Electrical Characteristics
–Data Sheet Rev.1.0
Absolute Maximum Ratings
Supply Voltage............................................................................................................... -0.3
Input Current................................................................................................................................25 mA
Digital Input Voltage ......................................................................................... -0.3V
Electrostatic Discharge............................................................................................................ +/- 1000V
Storage Temperature Range ............................................................................................ -50 to +125°C
Total Power Dissipation .............................................................................................................150mW
*Stresses beyond those listed under “Absolute Maximum Rati ngs” may cause permanent damage to the device. These are
stress ratings only. Functional operation of the device at these or any other conditions beyond those indicated under
“Operating Conditions” is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Operating Conditions
mbol Parameter
S
V
DD
T
AMB
Supply Vol tage Measurement mode,
Ambient Operating Temp.
*
”#9
”#:9
DD
”#9
”#9
5.5
+85
DD
+ 0.3V
V
°C
IN
Conditions Min. Typ.* Max. Unit
V
= 0 V
SS
4.5
-40
5.0
25
Range
V
IL
Input Low Voltage
V
SS
0.3 V
DD
V
V
IH
Input High Voltage**
0.7 V
DD
V
DD
* Typical figur es are at 25° C and ar e for design aid only; not guarant eed and not subject to product ion testing.
Note: Ext ernal Buffer-Capacitance is needed: e.g. 4.7uF between the Supply-Pins.
** Note: At pin PROG a higher volt age ( up to 8.5V) as defined for the z er o posi tion programming routine.
Programming Input
mbol Parameter
S
V
PROG
t
ZAP
t
ProgEN
t
LH
DC Character istics
Symbol Parameter
I
DD
Programming Voltage
Zap pulse durati on
Delay af ter CS=1
Pulse slew rate
Operating S upply Current Continuous Read Out
see Figure 4
Conditions Min. Typ. Max. Units
Conditions
8
4.5
200
2
Min.
15
5
Typ.
24
8.5
5.5
Max.
V
µs
µs
V/µs
Units
mA
Mode*
I
DD0
Power Down Current PD/CS=1
0.5
1
mA
V
I
OL
•
Note: I
Output Current, Sink VOL = 0.4V
in Single Read Out Mode is the same during the m easurement phase
DD
1
mA
Rev. n/c Page 6/11 Feb 2001
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6-Bit Magnetic Position Encoder
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AS5020
Timing Characteristics
–Data Sheet Rev.1.0
mbol Parameter
S
t
SetUp
t
Reset
t
meas
Set up time aft er power on
Minimum reset durat ion
Min. waiting time for a singl e
measurement *
t
clkDATA
t
latch
T
CLK
Max. CLK-DATA valid delay
Min. Hol d time after lat c hing
Data shift clock periode
Vdd
PD/CS
CLK
DATA
Conditions Min. Typ. Max. Unit
20
1
20
5
1
D5 D4 D3 D2 D1 D0 NVR Parity
10
µs
µs
µs
ns
µs
us
t
SetUp tReset tmeas tlatch TCLKtclkDATA
Figure 5 Timing Characteristics Single Read O ut Mode
Vdd
PD/CS
1 2 3 4 5 6 7 8 9 1 2 3
CLK
DATA
t
SetUp
*Note: Multiple l atching of 1 measured value in Conti nuous Read Out Mode is possible due to internal anti -
collision of the Value Update.
MSB LSB MSBNVR Parity
Figure 6 Timing Characteristics Continuous Read Out Mode
Rev. n/c Page 7/11 Feb 2001
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6-Bit Magnetic Position Encoder
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AS5020
Magnetic Input Characteristics*
–Data Sheet Rev.1.0
mbol Parameter
S
B
min-max
Processing magnetic field
Conditions
Min.
Typ.
Max.
Units
At package surf ac e 30 40 50 mT
strength input r ange
Off
mag
DistF
Magnetic Offset 5
Magnetic distortion factor Sinusoidal magnet ic fi eld
mag
2 3 %
mT
density along 3mm
concentric circle.
T
d
Magnet Tem per ature drift -0.035
%/K
D Diamet er of encoder m agnet 3 6 mm
f Input frequency Both directions 30000 rpm
*Note: Please ask for our prefer r ed M agnet Supplier List.
Output Characteristics
mbol
S
RES Resolution
LSB Minimum step
INL Integr al Non-Lineari ty See Note 1)
DNL Differential Non- Linearity
TN Transition-Noise
Parameter
Conditions Min. Typ. Max. Units
6
No missing codes guaranteed
5.625
0.1
0.5
0.5
bits
deg
LSB
LSB
LSB
1) Linearit y is defined in terms of end point f it and guaranteed by design, proved by si mulated t est si gnals
αααα
6bit
63
2
1
0
5.625
°
32
0
0
°
Figure 5 Output v alue v er s us input angle
180
°
360
°
αααα
Rev. n/c Page 8/11 Feb 2001
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6-Bit Magnetic Position Encoder
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AS5020
Magnet Placement
–Data Sheet Rev.1.0
mbol Parameter
S
R
Disp
Displacem ent radius of
rotational axis with
reference to pins
Z
Dist
Distance between
permanent magnet and
package surface
Conditions
Magnet centered on rotational
Min.
Typ.
Max.
250
Units
µm
axis
With ref er enc e magnet (depends
1 mm
on used magnet;)
Z
Dist
R
Disp
Referenced to pins
R
Disp
Rev. n/c Page 9/11 Feb 2001
Page 10
6-Bit Magnetic Position Encoder
AS5020
Non Contact Rotary Sw i tch:
„
4, 8,16,32 Position Rotary Switch
„
n of 64 Position Rotary Switch
„
Digital Potentiometer, Dimmer
„
Angular Encoding
Advantages:
•
No switch contacts
•
Long mechanical life time
•
Digital output
–Data Sheet Rev.1.0
Typical Application Areas
„
Position Control
„
Isolated Switching
„
Rotation Detection
„
and many more
Similar to Daisy Chain configuration
Figure 6 Front P anel Control
multiple devices can be connected over
a serial bus structure. In this
configuration the PROG pins can be
connected together and allows
simultaneous calibration.
Address
µµµµ
C
CLK
Data IN
Address
Decoder
n
PD/CS PROG
AS5020
CLK DATA
PD/CS PROG
AS5020
CLK DATA
Figure 7 Serial Bus Structure
Parallel
12
Programming
PD/CS PROG
AS5020
CLK DATA
For your interest:
A demonstration board for the AS5020 is available. The board includes the AS5020, an encoder
magnet, Micro-Controller and LED Display to indicate the position. Please ask your local sales
office. Further information can be found at our web-page:
http://www.amsint.com/products/product/index.html
Rev. n/c Page 10/11 Feb 2001
Page 11
6-Bit Magnetic Position Encoder
AS5020
Headquarters:
Austria Mikro Systeme
International AG
Schloß Prem stätten
A-8141 Unterpremstätten, Austria
Tel: +43 (3136) 500-0
Fax: +43 (3136) 525 01, 536 50
email: info@amsint.com
http: www.amsint.com
Sales Offices:
–Data Sheet Rev.1.0
Germany:
Tegernseer Landstrasse 85
D-81539 München
Tel.: +49 (89) 69 36 43-0
Fax: +49 (89) 69 36 43-66
France:
124 Avenue de Paris
F-94300 Vincennes
Tel.: +33 (1) 43 74 00 90
Fax: +33 (1) 43 74 20 98
Sweden:
Sjöängsvä gen 7
S-19272 Sollentuna
Stockholm, Sweden
Tel.: +46 (8) 754 93 95
Fax: +46 (8) 754 45
Wilhelm-Busch-Platz 1
D-22850 Hamburg/Norderstedt
Tel.: +49 (40) 522 80 13
Fax: +49 (40) 522 80 99
United Kingdom:
Coliseum Business Ce ntre
Watchmoor Pa rk
Camberley, Surrey
England GUIS 3YL
Tel.: +44 (1276) 23 3 99
Fax: +44 (1276) 29 3 53
ltaly:
Via Leone Tolstoi, 64
I-20146 Milano
Tel.: +39 02 423 67 13
Fax: +39 02 422 90 889
Amselweg 8
D-72820 Sonnenbühl
Tel.: +49 (7128) 92 71 28
Fax: +49 (7128) 92 71 40
USA:
Suite 300
4030 Wake Fo rest Road
Raleigh
NC27609
Tel.: +1 (919) 349 7551
Fax: +1 (509) 696 2713
Japan:
Shin Yokohama Daini Center Bldg. 10F
3-19-5, Shin Yokohama
Kohoku-ku, Yokohama 222-0033
Tel.: +81 (45) 474 0962
Fax: +81 (45) 472 9845
Devices sold by Austria Mikro Systeme are covered by the warranty and patent idemnification provisions appearing in its Term of Sale. Austria Mikro Systeme
makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from
patent infringement. Austria Mikro Systeme 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 Austria Mikro Systeme for current information. This product is intended for use in normal commercial
applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical lifesupport or life-sustaining equipment are specifically not recommended without additional processing by Austria Mikro Systeme for each application
Copyright © 2001, Austria Mikro Systeme Internat ional AG, Schl oss Pr emstätten, 8141 Unterpremstätten, Austria. 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. The informa tion
furnished here by Au st r ia Mikro S yst eme is bel ieved t o be cor r ect a nd accura te. H owever , Austria Mi k r o Syst eme sha l l not be l iable to recipient or any t hird pa rty
for any damages, inclu di ng bu t not l imi ted to per sona l i njury, property da ma ge, loss of profits, loss of use, i nter ruption of business or indir ect, specia l , i nci denta l 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
recipient or any third party shall arise or flow out of Austria Mikro Systeme rendering of technical or other services.
Rev. n/c Page 11/11 Feb 2001
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