AS5045
12-Bit Programmable Magnetic Rotary
Position Sensor
General Description
The AS5045 is a contactless magnetic position sensor 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
0.0879° = 4096 positions per revolution. This digital data is
available as a serial bit stream and as a PWM signal.
An internal voltage regulator allows the AS5045 to operate at
either 3.3 V or 5 V supplies.
Ordering Information
and
Content Guide
appear at end of
datasheet.
Key Benefits & Features
The benefits and features of AS5045, 12-Bit Programmable
Magnetic Rotary Position Sensor are listed below:
Figure 1:
Added Value of Using AS5045
Benefits
•
Highest reliability and durability in harsh
environments
•
Great flexibility during assembly
•
Operation safety
•
Lower material cost (no magnetic
shielding needed)
Features
•
Contactless absolute angle position measurement
•
User programmable zero position
•
Diagnostic modes for magnet detection and power supply
loss
•
Immune to external magnetic stray fields
•
Two digital 12-bit absolute outputs:
• Serial interface and
• Pulse width modulated (PWM) output
•
Failure detection mode for magnet placement monitoring
and loss of power supply
•
“Red-Yellow-Green” indicators display placement of magnet
in Z-axis
ams Datasheet
[v2-01] 2017-Jul-13
Page 1
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AS5045 −
General Description
•
Serial read-out of multiple interconnected AS5045 devices
using Daisy Chain mode
•
Tolerant to magnet misalignment and airgap variations
•
Wide temperature range: - 40ºC to 125ºC
•
Small Pb-free package: SSOP-16 (5.3mm x 6.2mm)
Applications
The AS5045 is ideal for industrial applications like
•
Robotics,
•
Stepper motor control,
•
RC servo control and
•
Replacement of high-end potentiometers.
Block Diagram
The functional blocks of this device are shown below:
Figure 2:
AS5045 Block Diagram
VDD3V3
MagINCn
MagDECn
PWM
Interface
Sin
Ang
VDD5V
LDO 3.3V
PWM
Hall Array
&
Frontend
Amplifier
Cos
DSP
Mag
Absolute
Interface
(SSI)
DO
CSn
CLK
OTP
Register
Prog_DI
Mode
AS5045
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ams Datasheet
[v2-01] 2017-Jul-13
AS5045 −
Pin Assignment
Pin Assignment
Figure 3:
Pin Assignment (Top View)
MagINCn
MagDECn
NC
NC
NC
Mode
VSS
Prog_DI
1
2
16
15
VDD5V
VDD3V3
NC
NC
PWM
CSn
CLK
DO
4
5
6
7
8
AS5045
3
14
13
12
11
10
9
Pin Description
Figure 4
shows the description of each pin of the standard
SSOP16 package (Shrink Small Outline Package, 16 leads, body
size: 5.3mm x 6.2mmm; see
Figure 3).
Pins 7, 15 and 16 supply
pins, pins 3, 4, 5, 6, 13 and 14 are for
internal use and must not be connected.
Pins 1 and 2 MagINCn and MagDECn
are the magnetic field
change indicators (magnetic field strength increase or decrease
through variation of the distance between the magnet and the
device). These outputs can be used to detect the valid magnetic
field range. Furthermore those indicators can also be used for
contact-less push-button functionality.
Pin 6 Mode
allows switching between filtered (slow) and
unfiltered (fast mode). This pin must be tied to VSS or VDD5V,
and must not be switched after power up. See
Mode Input Pin.
Pin 8 Prog
is used to program the zero-position into the OTP.
See
Zero Position Programming.
This pin is also used as digital input to shift serial data through
the device in Daisy Chain configuration. See
Daisy Chain Mode.
Pin 11 Chip Select
(CSn; active low) selects a device within a
network of AS5045 magnetic position sensors and initiates
serial data transfer. A logic high at CSn puts the data output pin
(DO) to tri-state and terminates serial data transfer. This pin is
also used for alignment mode and programming mode (see
Figure 27).
ams Datasheet
[v2-01] 2017-Jul-13
Page 3
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AS5045 −
Pin Assignment
Pin 12 PWM
allows a single-wire output of the 10-bit absolute
position value. The value is encoded into a pulse width
modulated signal with 1μs pulse width per step (1μs to 4096μs
over a full turn). By using an external low pass filter, the digital
PWM signal is converted into an analog voltage, making a direct
replacement of potentiometers possible.
Figure 4:
Pin Description
Pin
Number
1
Pin Name
Pin Type
Description
Magnet Field
Magnitude INCrease;
active low, indicates
a distance reduction between the magnet and the
device surface (see
Figure 16).
Magnet Field
Magnitude DECrease;
active low,
indicates a distance increase between the device and
the magnet see
Figure 16).
MagINCn
Digital output open
drain
2
3
4
5
6
7
8
MagDECn
NC
NC
NC
Mode
VSS
Prog_DI
-
-
-
-
Supply pin
Digital input
pull-down
Digital output /
tri-state
Digital input,
Schmitt-Trigger input
Digital input pull-up,
Schmitt-Trigger input
Digital output
-
Must be left unconnected
Select between slow (low, VSS) and fast (high, VDD5V)
mode. Internal pull-down resistor. Must be hard-wired
on the PCB in application.
Negative Supply Voltage (GND)
OTP
Programming
Input and Data Input for Daisy Chain
mode. Internal pull-down resistor (~74kΩ). Connect to
VSS if not used
Data Output
of Synchronous Serial Interface
Clock
Input of Synchronous Serial Interface;
Schmitt-Trigger input
Chip Select,
active low; Schmitt-Trigger input, internal
pull-up resistor (~50kΩ)
Pulse Width Modulation
of approx. 244Hz; 1μs/step
(optional 122Hz; 2μs/step)
Must be left unconnected
9
10
11
12
13
14
15
16
DO
CLK
CSn
PWM
NC
NC
VDD3V3
-
3V-Regulator Output, internally regulated from VDD5V.
Connect to VDD5V for 3V supply voltage. Do not load
externally.
Positive Supply Voltage, 3.0 to 5.5 V
Supply pin
VDD5V
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AS5045 −
Absolute Maximum Ratings
Absolute Maximum Ratings
Stresses beyond those listed in
Absolute Maximum Ratings
may
cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any
other conditions beyond those indicated in
Electrical
Characteristics
is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device
reliability.
Figure 5:
Absolute Maximum Ratings
Parameter
Min
Max
Units
Comments
Electrical Parameters
DC supply voltage at pin VDD5V
DC supply voltage at pin
VDD3V3
Input pin voltage
Input current (latchup immunity)
-0.3
-100
-0.3
7
5
VDD5V
+0.3
100
V
V
V
mA
Except VDD3V3
EIA/JESD78 Class II Level A
Electrostatic Discharge
Electrostatic discharge
±2
kV
JESD22-A114E
Temperature Ranges and Storage Conditions
Storage temperature
-55
150
ºC
Min -67ºF; Max 302ºF
The reflow peak soldering temperature
(body temperature) specified is in
accordance with IPC/JEDEC J-STD-020
“Moisture/Reflow Sensitivity Classification
for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded
packages is matte tin (100% Sn).
Package body temperature
260
ºC
Relative humidity
non-condensing
Moisture sensitivity level (MSL)
5
3
85
%
Represents a maximum floor life time of
168h
ams Datasheet
[v2-01] 2017-Jul-13
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