ams AS5055A Low power 12-bit magnetic position sensor Datasheet

AS5055A
Low Power 12-Bit Magnetic Position
Sensor
General Description
The AS5055A is a single-chip on-axis magnetic rotary position
sensor with low voltage and low power features.
It includes an integrated Hall element array, a high resolution
ADC and a smart power management controller.
The angle position, alarm bits and magnetic field information
are transmitted over a 3-wire or 4-wire SPI interface to the
microcontroller.
The AS5055A is available in a compact QFN 16-pin 4x4x0.85 mm
package and specified over an operating temperature of -40ºC
to 85ºC.
Ordering Information and Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of AS5055A, Low Power 12-Bit
Magnetic Position Sensor are listed below:
Figure 1:
Added Value of Using AS5055A
Benefits
Features
Precise and reliable absolute angle measurement
12-bit absolute angle position indication
Very low power consumption
3μA current consumption in low power mode
High reliability sensing
Immune to external magnetic stray fields
Synchronization between microcontroller and sensor
Interrupt pin displays availability of new data
Ideal for small and compact designs
QFN-16 4x4 package
Industry-standard interface
3- or 4-wire SPI interface
ams Datasheet
[v2-03] 2014-Jul-31
Page 1
Document Feedback
AS5055A − General Description
Applications
This sensor is optimized for a broad range of demanding
applications including:
• Servo motor control
• Battery operated systems
• Robotics
Block Diagram
The functional blocks of this sensor are
shown below:
Figure 2:
AS5055A Block Diagram
VDD
VDDp WM
AS5055A
SPI
Low Power Management
SS/
SCK
MISO
MOSI
EN_INT/
Hall Sensors
Analog
Front-End
ADC
ATAN
(CORDIC)
INT/
AGC
VSS
Page 2
Document Feedback
Test
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Pin Assignment
The AS5055A pin assignments are shown below.
Pin Assignment
Figure 3:
Pin Diagram
NC
INT/
WM
VSS
Pin Assignments (Top View):
Package drawing is not to scale.
16
15
14
13
MOSI
1
12
VDD
MISO
2
11
VDDp
SCK
3
10
EN_INT/
SS/
4
9
5
6
7
8
NC
NC
NC
NC
Epad
Test
Figure 4:
Pin Description
Pin Number
Name
Type
1
MOSI
Digital input
2
MISO
Digital output, tri-state buffer
SPI bus data output
3
SCK
Digital input Schmitt trigger
SPI clock
4
SS/
Digital input
5
NC
6
NC
7
NC
8
NC
9
Test
Analog
10
EN_INT/
Digital input
-
ams Datasheet
[v2-03] 2014-Jul-31
Description
SPI bus data input
SPI Slave Select, active low
Leave unconnected
Test pin, connect to VSS
Enable interrupt, active low
Page 3
Document Feedback
AS5055A − Pin Assignment
Pin Number
Name
11
VDDp
12
VDD
13
VSS
14
WM
Digital I/O
15
INT/
Digital output, tri-state buffer
16
NC
-
Leave unconnected
Epad
-
-
Exposed pad, leave unconnected
Page 4
Document Feedback
Type
Description
Peripheral power supply, 1.8V to VDD
Supply
Analog and digital power supply, 3.0V to
3.6V
Ground
Low: 3-wire mode
High: 4-wire mode
Interrupt output. Active LOW, when
conversion is finished
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Absolute Maximum Ratings
Stresses beyond those listed in “Absolute Maximum Ratings” on
page 5 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” on page 6 is not implied. Exposure
to absolute maximum rating conditions for periods may affect
device reliability.
Absolute Maximum Ratings
Figure 5:
Absolute Maximum Ratings
Symbol
Parameter
Min
Max
Units
Comments
Electrical Parameters
VDD
DC supply voltage
-0.3
5.0
V
VDDp
Peripheral supply voltage
-0.3
VDD+0.3
V
VIN
Input pin voltage
-0.3
5.0
V
Iscr
Input current (latchup
immunity)
-100
100
mA
Norm: JEDEC 78
kV
Norm: MIL-STD-883 E method
3015
Electrostatic Discharge
ESD
Electrostatic discharge
±1
-
Continuous Power Dissipation
ΘJA
Pt
Package thermal resistance
-
Total power dissipation
33.5
°C/W
36
mW
Velocity=0, Multi Layer PCB;
JEDEC Standard Testboard
Temperature Ranges and Storage Conditions
Tstrg
TBODY
Storage temperature
125
Package body temperature
Humidity non-condensing
MSL
-55
Moisture Sensitive Level
ams Datasheet
[v2-03] 2014-Jul-31
5
3
°C
260
°C
85
%
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).
Represents a maximum floor life
time of 168h
Page 5
Document Feedback
AS5055A − Electrical Characteristics
Electrical Characteristics
Operating Conditions
Figure 6:
Operating Conditions
Symbol
Parameter
Conditions
Min
Max
Units
VDD
DC supply voltage
3.0
3.6
V
VDDp
Peripheral supply voltage
1.8
VDD
V
Input pin voltage
-0.3
VDDp +0.3
V
Ambient operating
temperature
-40
85
°C
2.2
4.7
μF
15
33
Ω
VIN
Tamb
External components
Power supply filter, pin VDD
(see “Power Supply Filter”
on page 10)
Ceramic capacitor, pin VDDp
to VSS
100
nF
System Parameters
Figure 7:
System Parameters
Symbol
Ion
Ioff
Parameter
Current consumption
Current consumption
Conditions
Min
Typ
Max
Units
Normal operating mode
8.5
mA
Low power mode with activated
POR
(POR_OFF = 0x00) – default
setting
33
μA
Low power mode with
deactivated POR
(POR_OFF = 0x5A)
3
μA
treadout
Readout rate
Time between READ ANGLE
command and INTERRUPT
500
μs
tPwrUp
Power up time
Minimum time after power up
before the sensor is operational
580
μs
Rd
Lateral displacement
range
Misalignment of the center of the
magnet to the center of the die
±0.5
mm
BZ
Magnetic input field
30
90
mT
BZ00
Magnetic input field
range
58
90
mT
Page 6
Document Feedback
Gain = 00
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
BZ01
Magnetic input field
range
Gain = 01
51
80
mT
BZ10
Magnetic input field
range
Gain = 10
39
62
mT
BZ11
Magnetic input field
range
Gain = 11
30
47
mT
N00
Noise (rms)
Within Bz00 magnetic input field
range and Gain = 00
0.128
degrms
N01
Noise (rms)
Within Bz01 magnetic input field
range and Gain = 01
0.149
degrms
N10
Noise (rms)
Within Bz10 magnetic input field
range and Gain = 10
0.192
degrms
N11
Noise (rms)
Within Bz11 magnetic input field
range and Gain = 11
0.256
degrms
INL
Integral Non Linearity
Using Bomatec 6x2.5 mm NdFeB
magnet with a maximum
x/y-displacement radius of 250
μm from package center
-1.41
1.41
deg
RPU/PD
Recommended pull-up
or pull-down resistor
Applicable for daisy chain
configuration
10k
50k
Ω
DC/AC Characteristics
Digital pads: MISO, MOSI, SCK, SS/, EN_INT/, INT/, WM
Figure 8:
DC/AC Characteristics
Symbol
Parameter
Conditions
Min
Max
Units
VIH
High level input voltage
VIL
Low level input voltage
VDDp > 2.7V
0.3 * VDDp
V
VIL
Low level input voltage
VDDp < 2.7V
0.25 * VDDp
V
1
μA
ILEAK
Input leakage current
VOH
High level output voltage
VOL
Low level output voltage
CL
Capacitive load
ams Datasheet
[v2-03] 2014-Jul-31
0.7 * VDDp
V
VDDp - 0.5
V
VSS + 0.4
V
35
pF
Page 7
Document Feedback
AS5055A − Detailed Description
Detailed Description
Noise Performance
This figure shows the Worst Case Noise Performance of the
AS5055A at different gain settings which can be set in the Gain
Register.
Figure 9:
Worst Case Noise Performance of the AS5055A
0.5
0.45
0.4
rms Noise [degrees]
0.35
0.3
N 11
0.25
N 10
N 01
N 00
0.2
0.15
0.1
0.05
0
0
10
20
30
40
50
60
70
80
90
100
Bz [mT]
Page 8
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Detailed Description
Typical Application
The AS5055A uses on-chip Hall elements to convert the
magnetic field component perpendicular to the surface of the
chip into a voltage.
The signals from the Hall elements are amplified and filtered by
the analog front-end (AFE) before being converted by the
analog-to-digital converter (ADC). The output of the ADC is
processed by the hardwired CORDIC (coordinate rotating
digital computer) block to compute the angle and magnitude
of the magnetic vector. The intensity of the magnetic field
(magnitude) is used by the automatic gain control (AGC) to
adjust the amplification level for compensation of temperature
and magnetic field variations.
The internal 12-bit resolution is available by reading a register
through the SPI interface. The IC settings in the AS5055A can
be programmed through the SPI interface without any
dedicated programmer.
Figure 10:
Typical Application Using SPI 4-Wire Mode and INT/ Output
DC 3.0V – 3.6V
4.7µF
15 R
DC 1.8V – 3.6V
100nF
VDD
VDDp
WM
AS5055A
SS/
SCK
MISO
MOSI
SPI
Low Power Management
SPI
Interface
EN_INT/
Hall Sensors
µC
Analog
Front-End
INT/
ADC
ATAN
(CORDIC)
Interrupt
AGC
VSS
Test
Figure 10 shows how the AS5055A can be connected to a
microcontroller. The SPI interface is a slave interface for
accessing the on-chip registers. The INT/ output is an active-low
interrupt for informing the host microcontroller when a new
result is available.
ams Datasheet
[v2-03] 2014-Jul-31
Page 9
Document Feedback
AS5055A − Detailed Description
Power Supply Filter
Due to the sequential internal sampling of the Hall sensors,
fluctuations on the analog power supply (pin#12: VDD) may
cause additional jitter of the measured angle. This jitter can be
avoided by providing a stable VDD supply.
The easiest way to achieve that is to add a RC filter: 15Ω in series
and 4.7μF to ground as shown in Figure 10.
Alternatively, a filter: 33Ω + 2.2μF may be used. However with
this configuration, the minimum supply voltage is 3.15V.
Reading an Angle
Sending a READ ANGLE command through the SPI interface
automatically powers up the chip, drives INT/ high and starts
another angle measurement. The completion of the angle
measurement is indicated by driving the INT/ output low and
clearing the WOW flag in the error status register. The
microcontroller can respond to the interrupt by reading the
angle value from the AS5055A over the SPI interface. (See
Figure 11).
A READ ANGLE command must not be sent while a
measurement is being performed as indicated by INT/ driven
high or WOW = 1.
Reducing the Angle Jitter
The chip only performs a single angle measurement after a
READ ANGLE command is received, after which it returns to
low-power mode, so it is in normal operating mode for only a
very short time (t PwrUp).
The angle jitter can be reduced by averaging several angle
measurements in the microcontroller. For example, an
averaging of four samples reduces the jitter by 6dB (50%).
Operating Modes
After a READ ANGLE command is sent, the angle is measured
and internal calculations are started. During this time (normal
operating mode) the INT/ output is high until the device finishes
the calculations and a second READ ANGLE command may not
be sent.
After the INT/ output is driven low the device goes into
low-power mode. If the microcontroller doesn't monitor the
INT/ output a minimum guard time (treadout) must be inserted
before the next READ ANGLE command can be sent.
After startup the AS5055A has higher power consumption than
during low-power mode. When the POR cell is deactivated the
chip uses less current during low-power mode (see POR Off
Register).
Page 10
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Detailed Description
Figure 11:
Operating Modes
MOSI
Read angle
Read angle
CS/
INT/
Operating mode
Communication
mode
Normal operating mode
Low power mode
Communication
mode
treadout
Note(s) and/or Footnote(s):
1. Even in low power mode, the power supply must be capable of supporting the active current (I on ) at least for maximum t readout,
until the AS5055A is suspended to low power mode.
Daisy Chain
The AS5055A allows a Daisy Chain configuration as shown in
Figure 21.
In this configuration the microcontroller can read multiple
AS5055A chips using only 5 wires.
ams Datasheet
[v2-03] 2014-Jul-31
Page 11
Document Feedback
AS5055A − SPI Inter face
The 16-bit SPI interface provides read/write access to the
on-chip registers. The interface only supports slave operation
mode. It communicates at clock rates up to 10 MHz.
SPI Interface
The AS5055A SPI uses mode=1 (CPOL=0, CPHA=1) to exchange
data. As shown in Figure 12, a data transfer starts with the
falling edge of CSn (SCL is low). The AS5055A samples the MOSI
input on the falling edge of SCL. SPI commands are executed at
the end of the frame (rising edge of CSn). The bit order is MSB
first. Data is protected by parity.
SPI Timing
Figure 12:
SPI Timing Diagram
tCSn
CSn
(Input)
tL
tclk
tclkL
tclkH
tH
CLK
(Input)
tMISO
tOZ
MISO
(Output)
data[15]
data[14]
data[0]
tOZ
tMOSI
MOSI
(Input)
Page 12
Document Feedback
data[15]
data[14]
data[0]
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − SPI Interface
Figure 13:
SPI Timing
Parameter
Description
Min
Max
Unit
tL
Time between CSn falling edge and CLK rising edge
50
ns
tclk
Serial clock period
100
ns
tclkL
Low period of serial clock
50
ns
tclkH
High period of serial clock
50
ns
Time between last falling edge of CLK and rising edge
of CSn
50
ns
tCSn
High time of CSn between two transmissions (1)
50
ns
tMOSI
Data input valid to falling clock edge
20
ns
tMISO
CLK edge to data output valid
35
ns
Release bus time after CS rising edge.
50
ns
tH
tOZ
Note(s) and/or Footnote(s):
1. If the previous command was a READ ANGLE command (0x3FFF) a minimum time of readout has to be waited before sending a next
READ ANGLE command. (see “Operating Modes” on page 10)
SPI Wire Mode Selection
The SPI interface can be set in two different modes: 3-wire mode
or 4-wire mode.
Figure 14:
Wire Mode Selection
ams Datasheet
[v2-03] 2014-Jul-31
WM (Pin 14)
Connection option
0
3-wire mode
1
4-wire-mode
Page 13
Document Feedback
AS5055A − SPI Inter face
SPI Transaction
An SPI transaction consists of a 16-bit command frame followed
by a 16-bit data frame. Figure 15 shows the structure of the
command frame.
SPI Command Frame
Figure 15:
SPI Command Frame
Bit
15
14
13
12
R/W
11
10
9
8
7
6
5
4
3
2
Address 14:1
Bit
Name
15
R/W
14:1
Address
0
PAR
1
0
PAR
Description
0=Write, 1=Read
14 bit address to read or write
Parity bit (even) calculated on the upper 15 bits
To increase the reliability of communication over the SPI, an
even parity bit (PAR) must be generated and sent. A wrong
setting of the parity bit causes the PARITY bit in the error status
register of the AS5055A to be set. The parity bit is calculated
from the upper 15-bits of the command frame. The 16-bit
command specifies the address and whether the transaction is
a read or a write.
Page 14
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − SPI Interface
SPI Read Data Frame
Figure 16:
SPI Read Data Frame
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
Data 15:2
Bit
Name
15:2
Data
1
EF
0
PAR
2
1
0
EF
PAR
Description
14 bit read data
0 = no command frame error occurred, 1 = error occurred
Parity bit (even) calculated on the upper 15 bits
The data is sent from the AS5055A to the microcontroller on the
MISO output. The parity bit PAR is calculated for the upper 15
bits. If an error is detected in the previous SPI command frame,
the EF bit is set. The addressed register is sampled on the rising
edge of CSn and the data is transmitted on MISO with the next
read command, as shown in Figure 17.
Figure 17:
SPI Read
CSn
MOSI
MISO
ams Datasheet
[v2-03] 2014-Jul-31
Command
Command
Command
Command
Read ADD[n]
Read ADD[k]
Read ADD[p]
Read ADD[m]
Data
Data
Data
Data ADD[n]
Data ADD[k]
Data ADD[p]
Page 15
Document Feedback
AS5055A − SPI Inter face
SPI Write Data Frame
Figure 18:
SPI Write Data Frame
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
Data 15:2
Bit
Name
15:2
Data
1
DC
Don’t Care
0
PAR
Parity bit (even) calculated on the upper 15 bits
1
0
DC
PAR
Description
14 bit write data
The parity bit PAR is calculated for the upper 15 bits.
In a SPI write transaction, the write command frame (e.g. Write
ADD[n]) is followed by a data frame (e.g. DATA [x]). In addition
to writing an address in the AS5055A, a write command frame
causes the old contents of the addressed register (e.g. DATA [y])
to be sent on MISO in the following frame. This is followed by
the new contents of the addressed register (DATA [x]) as shown
in Figure 19.
Figure 19:
SPI Write Transaction
CSn
Command
MOSI
Write ADD[n]
Data to write into ADD[n]
DATA(x)
Data content ADD[n]
MISO
Page 16
Document Feedback
Data ADD[n]
Command
Write ADD[m]
New Data content
of ADD[n]
DATA(x)
Data to write into ADD[m]
DATA(y)
Data content ADD[m]
Data ADD[m]
Command
Next
command
New Data content
of ADD[m]
DATA(y)
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − SPI Interface
SPI Connection to the microcontroller
Figure 20:
Single Slave Mode
4 wire mode
µC
MOSI
MOSI
MISO
MISO
SCK
SCK
SS/
SS/
INT/
INT/
1
MOSI
0xFFFF
Read angle 1
MISO
0xFFFF
Read angle 2
0xFFFF
Read angle 3
0xFFFF
Read angle 4
Angle 1
Angle 2
Angle 3
AS5055A
SS/
INT/
Wire Mode
3 wire mode (Read only)
MOSI
0xFFFF
MISO
MOSI
MISO
MISO
SCK
Angle 2
Angle 3
SS/
SCK
µC
Angle 1
AS5055A
SS/
SS/
INT/
INT/
1
INT/
Wire Mode
3 wire mode (Bi-Directional)
MOSI
MOSI
MISO
MISO
SCK
0xFFFF
Read angle 1
Angle 1
0xFFFF
Read angle 2
Angle 2
SS/
SCK
µC
AS5055A
SS/
SS/
INT/
INT/
0
ams Datasheet
[v2-03] 2014-Jul-31
MISO
INT/
Wire Mode
Page 17
Document Feedback
AS5055A − SPI Inter face
Daisy Chain, 4 Wire
Figure 21:
Daisy Chain, 4 Wire
INT/
µC
MOSI
MOSI
MISO
MISO
SCK
SCK
SS/
SS/
1
AS5055A
1
Wire Mode
En_INT/
INT/
MOSI
MISO
SCK
SS/
1
AS5055A
2
Wire Mode
En_INT/
INT/
MOSI
MISO
SCK
SS/
MOSI
MISO
0xFFFF
Read angle 3
0xFFFF
Read angle 2
AS5055A
3
1
Wire Mode
0
En_INT/
0xFFFF
Read angle 1
INT/
0xFFFF
Read angle 3
0xFFFF
Read angle 2
0xFFFF
Read angle 1
Angle 3
Angle 2
Angle 1
SS/
INT/
Page 18
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Registers
The on-chip registers are shown in Figure 22.
Registers
Figure 22:
Registers
Name
Address
Bits
Mod
Default
Description
POR Off
0x3F22
7:0
R/W
0x0000
Power On Reset Off
Software Reset
0x3C00
13:0
W
0x0000
Software Reset
Master Reset
0x33A5
13:0
W
0x0000
Master Reset
Clear EF
0x3380
13:0
R
0x0000
Clear Error Flag
NOP
0x0000
13:0
W
0x0000
No Operation
AGC
0x3FF8
5:0
R/W
0x0020
Automatic Gain Control
Angular Data
0x3FFF
13:0
R
0x0000
Measured Angle
Error Status
0x335A
13:0
R
0x0000
Error Status Register
System Config
0x3F20
9:13
R
0x000
System Configuration Register 1
POR Off (0x3F22)
Writing the value 0x5A to the POR Off Register (0x3F22)
deactivates the POR cell and reduces the current consumption
in low power mode (Ioff ).
Software Reset (0x3C00)
Writing to the Software Reset Register initiates a Software
Reset. With the RES SPI bit of the Data Package set to 1 it is
possible to reset the SPI registers. After a software reset a new
angle conversion is started; this is needed to set the AS5055A
into an initial state. This angle is not readable by the
microcontroller.
The AS5055A is ready as soon as INT/ is driven low or a minimum
time (treadout) has elapsed.
Figure 23:
Software Reset Command
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Content
0
1
1
1
1
0
0
0
0
0
0
0
0
0
DC
PAR
ams Datasheet
[v2-03] 2014-Jul-31
Page 19
Document Feedback
AS5055A − Registers
Figure 24:
Data Package
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
DC
2
1
0
RES
SPI
DC
PAR
Bit
Name
Description
15:3
DC
2
RES SPI
1
DC
Don’t Care
0
PAR
Parity bit (even) calculated on the upper 15 bits
Don’t Care
If set to 1 the SPI registers are reset as well
Master Reset (0x33A5)
Writing to the Master Reset Register initiates a Master Reset.
This is similar to the Software Reset with the difference that no
data package is needed.
Figure 25:
Master Reset Command
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Content
0
1
1
0
0
1
1
1
0
1
0
0
1
0
1
PAR
Clear Error Flag (0x3380)
Reading from the Clear Error Flag Register clears the Error Flag
which is contained in every Read Data Frame. The Read data is
0x0000 which indicates a successful clear command.
Figure 26:
Clear Error Flag Command
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Content
1
1
1
0
0
1
1
1
0
0
0
0
0
0
0
PAR
Page 20
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Registers
Possible Conditions which force the Error Flag to be set:
• Wrong parity
• Wrong command
• Wrong number of clocks
Note(s): If the error flag is set to 1 because of a communication
problem the flag remains set until a Clear Error Flag Command
is executed.
No Operation (0x0000)
The No Operation (NOP) command represents a dummy write
to the AS5055A. If no error happens the chip responds with
0x0000.
Figure 27:
NOP Command
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Content
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
PAR
AGC – Automatic Gain Control (0x3FF8)
Writing a value different than zero to this register, stops the AGC
loop and keeps a constant AGC value.
Figure 28:
AGC
Name
Read/Write
Bit Position
Description
AGC
R/W
5:0
Automatic Gain Control value
Angular Data (0x3FFF)
Figure 29:
Angular Data
Name
Read/Write
Bit Position
Alarm Lo
R
13
Alarm flag, which indicates a too low magnetic field
Alarm Hi
R
12
Alarm flag, which indicates a too high magnetic field
Angle Value
R
11:0
ams Datasheet
[v2-03] 2014-Jul-31
Description
Angular value in 12 bit binary code
Page 21
Document Feedback
AS5055A − Error Monitoring
Alarm Bits
Figure 30:
Alarm Bits
Alarm Hi
Alarm Lo
0
0
AGC level is higher than the minimum value and lower than the maximum
value.
0
1
AGC level is equal or even lower than the minimum level. Magnetic field is
too weak.
1
0
AGC level is equal or even higher than the maximum level. Magnetic field is
too strong.
1
Indicates if a major system error has occurred during the last READ ANGLE
command or if the WOW flag is active. During active WOW a READ ANGLE
command must not be sent. Error flags can be read out with the
error status register.
1
Description
Error Status (0x335A)
For detailed information of the Error Status Register please refer
to “Error Monitoring” on page 22.
System Configuration Register 1 (0x3F20)
Figure 31:
System Configuration Register
Name
Read/Write
Bit Position
Resolution
R
13:12
00 indicates 12 bit resolution
Chip ID
R
11:9
Silicon version 010
Gain
R
4:3
Sets gain setting
Error Monitoring
Description
The correct operation and communication of the AS5055A is
ensured by several error flags. Every read access is supported
by a communication error flag (EF) to indicate a transmission
error in a previous host transmission.
For additional information on the Error Status, please refer to
the application note AN5000_ErrorMonitoring.
Page 22
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Error Monitoring
Error Status Register
Figure 32:
Error Status Register and Description
Bit
Type
Description
Error Status DSP
13
Reserved
12
FIELD_ALARM_LO
AGC level is equal or even higher than the maximum level. Magnetic field is
too weak.
11
FIELD_ALARM_HI
AGC level is equal or even lower than the minimum level. Magnetic field is too
strong.
10
RANGE
The RANGE flag signals that the Hall bias circuit has reached the head room
limit. This might occur at the combination of low supply voltage, high
temperature and low magnetic field. In this case, manually reducing the AGC
setting (Figure 28) can be used to recover a valid Hall biasing condition.
9
CORDICOV
The CORDIC calculates the angle. An error occurs when the input signals of the
CORDIC are too large. The internal algorithm fails.
ADCOV
The ADCOV bit occurs if the magnetic input field strength is too large for at
least one Hall element. This can be the case if the magnet is displaced. Second
reason could be that the offset compensation after power up is not finished
yet. If this happens some dummy READ ANGLE commands may be sent to
settle the offset loop.
8
Error Status System
7
Reserved
6
Reserved
5
Reserved
4
WOW
When a READ ANGLE command is in progress, the WOW flag is set to 1. At the
end of the measurement the WOW flag is cleared to 0. Only in case of
deadlock the WOW flag is stuck high; in which case a MASTER RESET must be
sent to clear the deadlock.
Error Status SPI
3
Reserved
2
ADDMON
Set to high when non existing address is used.
1
CLKMON
Set to high when the amount of clock cycles is not correct.
0
PARITY
ams Datasheet
[v2-03] 2014-Jul-31
Set to high when the transmitted parity bit does not match to calculated
parity bit.
Page 23
Document Feedback
AS5055A − Package Drawings & Markings
The device is available in a 16-pin QFN (4x4x0.9 mm) package.
The axis of the magnet must be aligned over the center of the
package.
Package Drawings & Markings
Figure 33:
Package FN – Dual Flat No-Lead Packaging Configuration
YYWWXZZ
AS5055A @
Symbol
Min
A
0.80
0.90
1.00
A1
0
0.02
0.05
A3
RoHS
Green
Nom Max
0.20 REF
L
0.35
0.40
0.45
L1
0
-
0.15
b
0.25
0.30
0.35
D
4.00 BSC
E
4.00 BSC
e
0.65 BSC
D2
2.60
2.70
2.80
E2
2.60
2.70
2.80
aaa
-
0.15
-
bbb
-
0.10
-
ccc
-
0.10
-
ddd
-
0.05
-
eee
-
0.08
-
fff
-
0.10
-
N
16
Note(s) and/or Footnote(s):
1. Dimensions and tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. Angles are in degrees.
3. Dimension b applies to metallized terminal and is measured between 0.25mm and 0.30mm from terminal tip. Dimension L1
represents terminal full back from package edge up to 0.15mm is acceptable.
4. Coplanarity applies to the exposed heat slug as well as the terminal.
5. Radius on terminal is optional.
6. N is the total number of terminals.
Page 24
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Package Drawings & Markings
Figure 34:
Marking: YYWWXZZ
YY
WW
X
ZZ
Year (i.e. 04 for 2004)
Week
Assembly plant identifier
Assembly traceability code
Figure 35:
Vertical Cross Section of QFN 16-pin 4x4x0.85 mm package
Note(s) and/or Footnote(s):
1. All dimensions in mm.
2. Die thickness 0.254 ± 0.013
3. Adhesive thickness 0.010 ± 10, +0.01, -0.0025
4. Lead frame thickness 0.203 typ.
ams Datasheet
[v2-03] 2014-Jul-31
Page 25
Document Feedback
AS5055A − Ordering & Contact Information
Ordering & Contact Information
Figure 36:
Ordering Information
Ordering Code
Package
Marking
Delivery Form
Delivery Quantity
AS5055A-BQFT
16-pin QFN
AS5055A
13" Tape & Reel in dry pack
6000
AS5055A-BQFM
16-pin QFN
AS5055A
7" Tape & Reel in dry pack
500
Buy our products or get free samples online at:
www.ams.com/ICdirect
Technical Support is available at:
www.ams.com/Technical-Support
Provide feedback about this document at:
www.ams.com/Document-Feedback
For further information and requests, e-mail us at:
[email protected]
For sales offices, distributors and representatives, please visit:
www.ams.com/contact
Headquarters
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
Page 26
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − RoHS Compliant & ams Green Statement
RoHS Compliant & ams Green
Statement
RoHS: The term RoHS compliant means that ams AG products
fully comply with current RoHS directives. Our semiconductor
products do not contain any chemicals for all 6 substance
categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to
be soldered at high temperatures, RoHS compliant products are
suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br): ams Green
defines that in addition to RoHS compliance, our products are
free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous
material).
Important Information: The information provided in this
statement represents ams AG knowledge and belief as of the
date that it is provided. ams AG bases its knowledge and belief
on information provided by third parties, and makes no
representation or warranty as to the accuracy of such
information. Efforts are underway to better integrate
information from third parties. ams AG has taken and continues
to take reasonable steps to provide representative and accurate
information but may not have conducted destructive testing or
chemical analysis on incoming materials and chemicals. ams AG
and ams AG suppliers consider certain information to be
proprietary, and thus CAS numbers and other limited
information may not be available for release.
ams Datasheet
[v2-03] 2014-Jul-31
Page 27
Document Feedback
AS5055A − Copyrights & Disclaimer
Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 30, 8141
Unterpremstaetten, 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.
Devices sold by ams AG are covered by the warranty and patent
indemnification provisions appearing in its General Terms of
Trade. 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 AG “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 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 recipient or any third party shall arise or flow out
of ams AG rendering of technical or other services.
Page 28
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Document Status
Document Status
Document Status
Product Preview
Preliminary Datasheet
Datasheet
Datasheet (discontinued)
ams Datasheet
[v2-03] 2014-Jul-31
Product Status
Definition
Pre-Development
Information in this datasheet is based on product ideas in
the planning phase of development. All specifications are
design goals without any warranty and are subject to
change without notice
Pre-Production
Information in this datasheet is based on products in the
design, validation or qualification phase of development.
The performance and parameters shown in this document
are preliminary without any warranty and are subject to
change without notice
Production
Information in this datasheet is based on products in
ramp-up to full production or full production which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade
Discontinued
Information in this datasheet is based on products which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade, but these products have been superseded and
should not be used for new designs
Page 29
Document Feedback
AS5055A − Revision Information
Revision Information
Changes from 2-02 (2014-Jul-02) to current revision 2-03 (2014-Jul-31)
Page(1)
Updated Figure 13
13
Updated Figure 30
22
Updated Figure 32
23
Note(s) and/or Footnote(s):
1. Page numbers for the previous version may differ from page numbers in the current revision
Page 30
Document Feedback
ams Datasheet
[v2-03] 2014-Jul-31
AS5055A − Content Guide
Content Guide
ams Datasheet
[v2-03] 2014-Jul-31
1
1
2
2
General Description
Key Benefits & Features
Applications
Block Diagram
3
5
Pin Assignment
Absolute Maximum Ratings
6
6
6
7
Electrical Characteristics
Operating Conditions
System Parameters
DC/AC Characteristics
8
8
9
10
10
10
10
11
Detailed Description
Noise Performance
Typical Application
Power Supply Filter
Reading an Angle
Reducing the Angle Jitter
Operating Modes
Daisy Chain
12
12
13
14
14
15
16
17
18
SPI Interface
SPI Timing
SPI Wire Mode Selection
SPI Transaction
SPI Command Frame
SPI Read Data Frame
SPI Write Data Frame
SPI Connection to the microcontroller
Daisy Chain, 4 Wire
19
19
19
20
20
21
21
21
22
22
22
Registers
POR Off (0x3F22)
Software Reset (0x3C00)
Master Reset (0x33A5)
Clear Error Flag (0x3380)
No Operation (0x0000)
AGC – Automatic Gain Control (0x3FF8)
Angular Data (0x3FFF)
Alarm Bits
Error Status (0x335A)
System Configuration Register 1 (0x3F20)
22
23
Error Monitoring
Error Status Register
24
26
27
28
29
30
Package Drawings & Markings
Ordering & Contact Information
RoHS Compliant & ams Green Statement
Copyrights & Disclaimer
Document Status
Revision Information
Page 31
Document Feedback