A1334 Datasheet

A1334
Precision Hall-Effect Angle Sensor IC
FEATURES AND BENEFITS
• Contactless 0° to 360° angle sensor IC, for angular
position, rotational speed, and direction measurement
• Available with either a single die or dual independent die
housed within a single package
• Circular Vertical Hall (CVH) technology provides a
single-channel sensor system, with air-gap independence
• 12-bit resolution possible in low RPM mode, 10-bit
resolution in high RPM mode
• Angle Refresh Rate (output rate) configurable between
25 and 3200 µs through EEPROM programming
• Capable of sensing magnet rotational speeds in excess of
7600 rpm
• SPI interface allows use of multiple independent sensors
for applications requiring redundancy
• EEPROM programmable angle reference (0°) position
and rotation direction (CW or CCW)
• Absolute maximum VCC of 26.5 V for automotive
battery-powered applications
Packages:
Not to scale
DESCRIPTION
The A1334 is a 360° angle sensor IC that provides contactless
high-resolution angular position information based on magnetic
Circular Vertical Hall (CVH) technology. It has a system-onchip (SoC) architecture that includes: a CVH front end, digital
signal processing, and a digital (SPI) output. The A1334 is
ideal for automotive applications requiring high-speed 0° to
360° angle measurements, such as electronic power steering
(EPS) and throttle systems.
The A1334 supports a Low RPM mode for slower rate appli­
cations and a High RPM mode for high-speed applications.
High RPM mode is for applications that require higher refresh
rates to minimize error due to latency. Low RPM mode is for
applications that require higher resolution operating at lower
angular velocities.
As part of its signal processing functions, the A1334 includes
automotive-grade temperature compensation to provide
accurate output over the full operating temperature and voltage
ranges. The A1334 also includes EEPROM technology for
end-of-line calibration.
The A1334 is available as a single die in a 14-pin TSSOP, or
dual die in a 24-pin TSSOP. Both packages are lead (Pb) free
with 100% matte-tin leadframe plating.
Single SoC
14-pin TSSOP (LE package)
Dual Independent SoCs
24-pin TSSOP (LE package)
BYP(1)
VCC(1)
(Programming)
SoC die 1
To all internal circuits
Multisegment
CVH Element
Analog Front End
ADC
Rack
Bandpass
Filter
Diagnostics
BIAS(1)
EEPROM
Calibration
Parameters
MISO(1)
CS(1)
SPI
Interface
Control unit
Steering
sensor
Digital Processing
Data
Registers
Temperature
Compensation
Internal Calibration
Zero Angle
MOSI(1)
Motor
SCLK(1)
GND(1)
xxx2
SoC die 2 (optional)
Pin number parentheses refer to chip in dual SoC variant
A1334 Functional Block Diagram
A1334A-DS, Rev. 4
A1334 in Electronic Power Steering (EPS)
Application
A1334
Selection Guide
Part Number
A1334LLETR-T
A1334LLETR-60-T
A1334LLETR-30-T
A1334LLETR-DD-T
A1334LLETR-DD55-T
A1334LLETR-DD30-T
Precision Hall-Effect Angle Sensor IC
System Die
Single
Single
Single
Dual
Dual
Dual
Package
14-pin TSSOP
14-pin TSSOP
14-pin TSSOP
24-pin TSSOP
24-pin TSSOP
24-pin TSSOP
Packing*
4000 pieces per 13-in. reel
4000 pieces per 13-in. reel
4000 pieces per 13-in. reel
4000 pieces per 13-in. reel
4000 pieces per 13-in. reel
4000 pieces per 13-in. reel
Notes
Optimized for 900 G Field
Optimized for 600 G Field
Optimized for 300 G Field
Optimized for 900 G Field
Optimized for 550 G Field
Optimized for 300 G Field
*Contact Allegro™ for additional packing options.
SPECIFICATIONS
Absolute Maximum Ratings
Rating
Unit
Forward Supply Voltage
Characteristic
Symbol
VCC
Not sampling angles
26.5
V
Reverse Supply Voltage
VRCC
Not sampling angles
–18
V
5.5
V
All Other Pins Forward Voltage
VIN
All Other Pins Reverse Voltage
VR
Operating Ambient Temperature
TA
Maximum Junction Temperature
Storage Temperature
Notes
0.5
V
–40 to 150
ºC
TJ(max)
165
ºC
Tstg
–65 to 170
ºC
L range
THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information
Characteristic
Package Thermal Resistance
Symbol
RθJA
Test Conditions*
Value
Unit
LE-14 package
82
ºC/W
LE-24 package
117
ºC/W
*Additional thermal information available on the Allegro website.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A1334
Precision Hall-Effect Angle Sensor IC
Pin-Out Diagrams and Terminal List Table
Terminal List Table
DGND 1
BYP 2
14 DGND
13 CS
PinName
LE-24
4, 7, 9
4, 6
AGND_2
–
16, 18
BYP_1
2
2
External bypass capacitor terminal for internal regulator (die 1)
BYP_2
–
14
External bypass capacitor terminal for internal regulator (die 2)
CS_1
13
23
SPI Chip Select terminal, active low (die 1)
12 MOSI
AGND 4
11 SCLK
AGND_1
VCC 5
10 MISO
VCC 6
9 AGND
8 BIAS
LE-14 Package
(Single SoC)
DGND_1 1
BYP_1 2
24 DGND_1
23 CS_1
Function
LE-14
DGND 3
AGND 7
Pin Number
Device analog ground terminal (die 1)
Device analog ground terminal (die 2)
CS_2
–
11
DGND_1
1, 3, 14
1, 3, 24
Device digital ground terminal (die 1)
SPI Chip Select terminal, active low (die 2)
DGND_2
–
12, 13, 15
Device digital ground terminal (die 2)
MISO_1
10
20
SPI Master Input / Slave Output (die 1)
MISO_2
–
8
SPI Master Input / Slave Output (die 2)
20 MISO_1
MOSI_1
12
22
SPI Master Output / Slave Input (die 1)
19 BIAS_1
MOSI_2
–
10
SPI Master Output / Slave Input (die 2)
DGND_1 3
22 MOSI_1
AGND_1 4
21 SCLK_1
VCC_1 5
AGND_1 6
BIAS_2 7
18 AGND_2
SCLK_1
11
21
SPI Clock terminal (die 1)
MISO_2 8
17 VCC_2
SCLK_2 9
16 AGND_2
SCLK_2
–
9
SPI Clock terminal (die 2)
MOSI_2 10
15 DGND_2
VCC_1
5, 6
5
Power supply; also used for EEPROM programming (die 1)
14 BYP_2
VCC_2
–
17
Power supply; also used for EEPROM programming (die 2)
BIAS_1
8
19
Bias connection; connect to ground (shown) or pull-up to 3.3 V (die 1)
BIAS_2
–
7
Bias connection; connect to ground (shown) or pull-up to 3.3 V (die 2)
CS_2 11
DGND_2 12
13 DGND_2
LE-24 Package
(Dual SoC)
V CC
0.1 µF
0.1 µF
0.1 µF
BYP_1
VCC_1 VCC_2
BYP_2
BIAS_1
CS_1
Host
Microprocessor
SCLK_1
MOSI_1
MISO_1
A1334
Target
Magnet
BIAS_2
CS_2
SCLK_2
MOSI_2
MISO_2
AGND_1 AGND_2 DGND_1 DGND_2
Typical Application Diagram (Dual Die Version)
Either or both internal SoCs can be operated simultaneously. (See page 12 for circuits that require a higher level of EMC immunity.)
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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A1334
Precision Hall-Effect Angle Sensor IC
OPERATING CHARACTERISTICS: valid over the full operating voltage and ambient temperature ranges, unless otherwise
noted
Characteristics
Symbol
Test Conditions
Min.
Typ.1
Max.
Unit2
Electrical Characteristics
Supply Voltage
VCC
Supply Current
ICC
Undervoltage Lockout Threshold
Voltage3
4.5
12
14.5
V
Each die, A1334 sampling angles
–
7.5
10
mA
VUVLOHI
Maximum VCC , dV/dt = 1V/ms, TA = 25°C,
A1334 sampling enabled
–
–
4.5
V
VUVLOLOW
Maximum VCC , dV/dt = 1V/ms, TA = 25°C,
A1334 sampling disabled
3.5
–
–
V
4.35
4.5
4.75
V
VCC Low Flag Threshold4,5
VUVLOTH
Supply Zener Clamp Voltage
VZSUP
Reverse-Battery Current
Power-On Time6,8
Bypass Pin Output Voltage7
26.5
–
–
V
VRCC = –18 V, TA = 25°C
–5
–
–
mA
–
300
–
µs
VBYP
TA = 25°C, CBYP = 0.1 µF
2.45
2.85
3.4
V
VIH
¯ S̄
¯ x pins
MOSIx, SCLKx, C̄
2.8
–
3.63
V
IRCC
ICC = ICC + 3 mA, TA = 25°C
tPO
SPI Interface Specifications
Digital Input High Voltage8
VIL
¯ S̄
¯ x pins
MOSIx, SCLKx, C̄
–
–
0.5
V
SPI Output High Voltage
VOH
MISOx pins, CL = 50 pF, TA = 25°C
2.81
3.3
3.79
V
SPI Output Low Voltage
VOL
MISOx pins, CL = 50 pF, TA = 25°C
–
0.3
0.5
V
fSCLK
MISOx pins, CL = 50 pF
Digital Input Low
SPI Clock
Voltage8
Frequency8
0.1
–
10
MHz
5.8
–
588
kHz
50
–
–
ns
Data output valid after SCLKx falling edge
–
40
–
ns
Input setup time before SCLKx rising edge
25
–
–
ns
tHD
Input hold time after SCLKx rising edge
50
–
–
ns
tCHD
¯ x rising
Hold SCLKx high time before C̄¯ S̄
edge
5
–
–
ns
CL
Loading on digital output (MISOx) pin
–
–
50
pF
B
Range of input field
SPI Frame Rate8
tSPI
Chip Select to First SCLK Edge8
tCS
Time from C̄¯ S̄¯ x going low to SCLKx falling
edge
Data Output Valid Time8
tDAV
MOSI Setup Time8
tSU
MOSI Hold
Time8
SCLK to CS Hold Time8
Load Capacitance8
Magnetic Characteristics
Magnetic Field9,10
Missing Magnet Flag
300
–
1000
G
100
–
G
–
12
–
bit
B = 300 G, TA = 25ºC, ORATE = 0
–
10.7
–
bits
High RPM mode 18
–
25
28.33
µs
Low RPM mode, AVG = 011 (varies
with AVG mode, refer to the appendix
Programming Reference)
–
200
–
µs
High RPM mode (see figure 4) 18
–
60
68
µs
MAGM
Angle Characteristics
Output11
Effective
RESANGLE
Resolution12
Angle Refresh Rate13,14
Response Time
tANG
tRESPONSE
Continued on the next page…
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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A1334
Precision Hall-Effect Angle Sensor IC
OPERATING CHARACTERISTICS (continued): valid over the full operating voltage and ambient temperature ranges, un-
less otherwise noted
Characteristics
Symbol
Test Conditions
Min.
Typ.1
Max.
Unit2
TA = 25°C, ideal magnet alignment,
B = 300 G, target rpm = 0
–
±0.6
–
degrees
TA = 150°C, ideal magnet alignment,
B = 300 G, target rpm = 0
–1.75
–
1.75
degrees
TA = 25°C, B = 300 G, no internal filtering
–
0.2
–
degrees
TA = 150°C, no internal filtering, B = 300 G,
target rpm = 0
–
0.27
–
degrees
TA = -40°C, B = 300 G
–
±1.5
–
degrees
TA = 150°C, B = 300 G
–1.5
–
–1.5
degrees
–
±1.0
–
degrees
Angle Characteristics (continued)
Angle
Error15
ERRANG
Angle Noise16, 19
NANG
Temperature Drift
ANGLEDRIFT
ANGLEDRIFT-
Angle Drift Over Lifetime17
LIFE
B = 300 G, typical maximum drift observed
after AEC-Q100 qualification testing
Typical data is at TA = 25°C and VCC = 5 V, and it is for design estimates only.
1 G (gauss) = 0.1 mT (millitesla).
3 At power-on, a die will not respond to commands until V
CC rises above V UVLOHI. After that, the die will perform and respond normally until V CC drops below V UVLOLOW .
4 Characterization data shows negligible accuracy degradation at supply voltages between 4.35 V and 4.50 V. Significant degradation in accuracy may occur
below 4.30 V.
5 VCC Low Threshold Flag will be sent via the SPI interface as part of the angle measurement.
6 During the power-on phase, the A1334 SPI transactions are not guaranteed.
7 Each die includes a linear regulator. The output voltage and current specifications are to aid in PCB design. The pin is not intended to drive any external circuitry.
8 Parameter is not guaranteed at final test. Values for this characteristic are determined by design.
9 The A1334 operates in magnetic fields lower than 300 G, but with reduced accuracy and resolution.
10 Contact Allegro for field optimization. In general, operation with larger magnetic field values result in improved performance (see Figures 3 and 4).
11 RES
ANGLE represents the number of bits of data available for reading from the die registers.
12 Effective Resolution is calculated using the formula below:
1
2
( )
32
log2 (360) - log2
l
l=1
where σ is the Standard Deviation based on thirty measurements taken at each of the 32 angular positions, I = 11.25, 22.5, … 360.
The rate at which a new angle reading will be ready.
To calculate Low RPM mode, time = 25 × 2AVG. Given AVG = 011 = 3 (decimal), so 23 = 8.
15 In general, Allegro’s angle sensor ICs are more accurate when stronger magnetic fields (i.e. 900 G) are used. Please contact Allegro for information regarding
how users can realize higher accuracy performance from Allegro’s angle sensor ICs by using stronger magnetic fields.
16 Value reflects 3 standard deviations.
17 After qualification testing, a typical IC drifted less than 0.5 degrees; however, after certain long duration stresses (for example 1000 cycles of -65 to 175 degree
C temperature cycling), a small number of devices drifted by approximately 1.5 degrees.
18 Maximum value based on worst case simulations.
19 One sigma value at 300 G. Operation with a larger magnetic field results in improved noise performance. For 600 G operation noise reduced by 50% vs 300 G.
13
14
Angle (º)
Applied Magnetic Field
Transducer Output
50
Response Time, tRESPONSE
0
t
Definition of Response Time
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115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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A1334
Precision Hall-Effect Angle Sensor IC
FUNCTIONAL DESCRIPTION
Operational Modes
The A1334 angle sensor device is designed to support a wide
variety of automotive applications requiring measuring 0° to 360°
angle positions.
An option for two electrically-independent die in the same
package provides solid-state consistency and reliability. Each die
SPI port can be configured in a different RPM mode. The data
output selection is controlled by the address request in the SPI
Read command.
The A1334 has dual identical system-on-chip (SoC) architecture.
The output of each die is used by the host microcontroller to
provide a single channel of target data.
Angle Measurement
The A1334 can monitor the angular position of a rotating magnet
at speeds ranging from 0 to more than 7600 rpm. At lower
rotational speeds, the A1334 provides high-resolution angle measurement accuracy. It can also support higher rates of rotational
speeds at reduced levels of angle measurement accuracy.
The A1334 can be configured to operate in two angular measurement modes of operation: Low RPM mode, and High RPM
mode. For applications that have a speed range from 0 to 500 rpm
(can vary with AVG), the Low RPM mode provides increased
resolution. For applications above 500 rpm, configuring the
A1334 in High RPM mode provides angle measurements with
standard resolution. Above 7600 rpm, the A1334 continues to
provide angle data; however, the accuracy is proportionally
reduced.
The actual update rate of Low RPM mode can be changed by
setting the AVG bits in the EEPROM. (See the appendix Programming Reference for details.) The selection of Low RPM mode or
High RPM mode can be programmed, via the Angle_Meas_Mode
bit, for the expected maximum rotational speed of the magnet
in operation to provide the highest corresponding level of angle
accuracy. However, the A1334 provides valid output data regardless of the selected mode and the application speed.
Although the range of the resolution of the measurement data
output, RESANGLE, is determined by the selection of either High
RPM or Low RPM mode, the measurement is also affected by
the intensity (B, in gauss) of the applied magnetic field from the
target. At lower intensities, a reduced signal-to-noise ratio will
cause one or two LSBs to change state randomly due to noise,
and the effective DAC resolution is reduced. These factors work
together, so when High RPM mode is selected, the effective
range of resolution is 8 to 10 bits (from lower to higher field
intensities), and in Low RPM mode, the effective range is 11 to
12 bits, depending on field strength and AVG selection.
Regardless of the field intensity and mode selection, the transmission protocol and number formatting remains the same. The MSB
is always transmitted first. The entire number should be read.
The Output Angle is always calculated at maximum resolution.
To be more explicit:
AngleOUT = 360 (°) × D[12:0] / (213)(1)
This formula is always true, regardless of the applied field
intensity. What changes with the field and speed setting is how
uniform the LSBs of the measurement data (D 12:x) will be.
When using the dual die version of the A1334, it should be noted
that the secondary die (E2) is rotated 180° relative to the primary
die (E1). This results in a difference in measurement of approximately 180° between the two die, given perfect alignment of each
die to the target magnet.
This phenomenon can be counteracted by subtracting the offset
using a microprocessor. Alternatively, the difference between the
two die can be compensated for using the EEPROM for setting
the Reference Angle.
System-Level Timing
The A1334 outputs a new angle measurement every tANG µs. In
High RPM mode, the A1334 outputs a new angle measurement
every tANG µs, with an effective resolution of 10 bits. There
is, however, a latency of tLAT , from when the rotating magnet
is sampled by the CVH to when the sampled data has been
completely transmitted over the SPI interface. Because an SPI
interface Read command is not synchronous with the CVH timing, but instead is polled by the external host microcontroller, the
latency can vary. For single back-to-back SPI transactions (first
transaction is sending the Read register 0x0 command, second is
retrieving the angle data) the following scenarios are possible:
• Worst case: 2 CVH cycle + 2 SPI cycles
• Best case: 1.5 SPI cycles; 2 µs, assuming a 10 MHz SPI clock
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6
A1334
Precision Hall-Effect Angle Sensor IC
Power-Up
Diagnostics
Upon applying power to the A1334, the device automatically runs
through an initialization routine. The purpose of this initialization
is to ensure that the device comes up in the same predictable
operating condition every power cycle. This initialization routine
takes a finite amount of time to complete, which is referred to as
Power-On Time, tPO .
The A1334 supports a number of on-chip self-diagnostics to
enable the host microcontroller to assess the operational status of
each die. For example, the A1334 can detect a low supply voltage
and includes an onboard watchdog timer to monitor that internal
clocks are running properly.
The A1334 wakes up in a default state that sets all SPI registers
to their default value. It is important to note that, regardless of the
state of the device before a power cycle, the device will re-power
with default values. For example, on every power-up, the device
will power up in the mode set in the EEPROM bit RPM. The
state of the EEPROM is unchanged.
Table 1: Diagnostic Capabilities
Diagnostic/ Protection
Description
Output State
Reverse VCC
Current Limiting (VCCx pin)
Output to VCC
Current Limiting (MISOx pin)
Output to Ground
Current Limiting (MISOx pin)
Watchdog
Monitors digital logic for proper function
IERR Error flag is set
Missing Magnet
Monitors magnet field level in case of mechanical failure
MAGM Error flag is set
EEPROM Error Detection
and Correction
Detection and correction of certain EEPROM memory bit errors
Error flags set in SPI message
when errors are detected or
corrected
Loss of VCC
Determine if battery power was lost
BATD Error flag is set
Redundancy
Dual die version of the A1334 provides redundant sensors in the same package
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115 Northeast Cutoff
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A1334
Precision Hall-Effect Angle Sensor IC
Undervoltage Lockout and VCC Low Flag
Diagnostic
The MISO pin state changes according to the state of the VCC
ramp, as shown in Figure 1.
VCC (V)
4.5
4.0
3.8
VCC Low Flag Threshold, VUVLOTH
Undervoltage Lockout Threshold
Voltage (high), VUVLOHI
Undervoltage Lockout Threshold
Voltage (Low),VUVLOLOW
Output
accuracy
reduced
1.5
MISO Pin
State
Output
accuracy
reduced
DIGON
High
Impedance
DIGON
Ground
VCC Low
Flag
Set
Accurate
Angle Output
VCC Low
Flag
Set
Ground
High
Impedance
t
Figure 1: Relationship of VCC and MISO Output
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A1334
Precision Hall-Effect Angle Sensor IC
APPLICATION INFORMATION
Calculating Target Zero Degree Angle
Bypass Pin Usage
When shipped from the factory, the default angle value when
orientated as shown in Figure 2, is approximately 40º (220º on
secondary die). In some cases, the end user may want to program
an angle offset in the A1334 to compensate for variation in
magnetic assemblies, or for applications where absolute systemlevel readings are required.
The Bypass pin is required for proper device operation and is
intended to bypass internal IC nodes of the A1334. A 0.1 µF
capacitor must be placed in very close proximity to the Bypass
pin. It is not intended to be used to source external components.
To assist with PCB layout, please see the Operating Characteristics table for output voltage and current requirements.
The internal algorithm for computing the output angle is as
follows:
Changing Sampling Modes
AngleOUT = AngleRAW – Reference Angle
The A1334 features a High RPM sampling mode, and a Low
RPM sampling mode. The default power-on state of the A1334
is loaded from EEPROM. To configure the A1334 to Low RPM
mode, set the Operating mode to Low RPM mode by writing a
logic 1 to bit 2 (RPM) of the configuration commands (CTRL)
register, via the SPI interface.
(2)
The procedure to zero out the A1334 is quite simple. During final
application calibration and programming, position the magnet
above the A1334 in the required zero-degree position, and read
the angle from the A1334 using the SPI interface (AngleOUT).
From this angle, the Reference Angle required to program the
A1334 can be computed as follows:
Reference Angle = AngleOUT(3)
Target rotation axis
Target poles aligned with
A1334 elements
Target alignment for default angle setting
• Target rotation axis intersects primary die
• Primary die 40° default point
• Secondary die 220° default point
(Example shows element E1 as primary die
element E2 as secondary die)
S
S
Pin 1
E1
N
E1
N
E2
E2
Figure 2: Orientation of Magnet Relative to Primary Die and Secondary Die
(dual die version used as example)
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115 Northeast Cutoff
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A1334
Precision Hall-Effect Angle Sensor IC
Magnetic Target Requirements
alignment configurations.
The A1334 is designed to operate with magnets constructed with
a variety of magnetic materials, cylindrical geometries, and field
strengths, as shown in Table 2. To reach this end, Allegro offers
three different “Field Optimization” or trim levels; 300 G, 550 G
and 900 G. Figure 8 demonstrates the typical 25ºC performance
for these three trim levels over field strength. In general, higher
field strengths result in improved performance in terms of angle
error and angle noise (see Figures 3 and 4) To obtain maximum
performance, it is important to match the operating field with the
field trim level. Contact Allegro for more detailed information on
magnet selection and performance.
Figure 6 illustrates the behavior of alignment error when using
an 8 mm diameter magnet positioned above the branded face of
the package. The curve shows the relationship between absolute
angle error present on the output of the die versus eccentricity of
the die relative to the rotation axis of the magnet. The curve is the
same for both dies in the package.
Redundant Applications and Alignment Error
The A1334 dual die version is designed to be used in redundant
applications with a single magnet spinning over the two separate
dies that are mounted side-by-side in the same package. One
challenge with this configuration is correctly lining up the magnet
with the device package, so it is important to be aware of the
physical separation of the two dies. Figure 5 depicts two possible
The curve provides guidance to determine what the optimal magnet placement should be for a given application. For example,
given that the maximum spacing between the two dies is 1 mm,
if the center of the magnet rotation is placed at the midpoint
between the two dies, each die will have a maximum eccentricity
of 0.5 mm.
For applications with reduced accuracy requirements, considering
one die the primary and the other die the secondary, the magnet
axis of rotation could be positioned directly above the primary
die, and thus offset 1 mm from the secondary die, yielding zero
alignment error on the primary die, and approximately ±1° of
absolute error on the secondary die due to geometric mismatch.
Table 2: Typical Target Magnet Parameters
Thickness
(mm)
15
4
10
2.5
8
2.5
6
2.5
Thickness
S
N
1.5
300 G Trim
recommended
range
Angle Error in Degrees
Diameter
(mm)
300 G Optimization
550 G Optimization
900 G Optimization
550 G Trim
recommended
range
900 G Trim
recommended
range
1
0.5
Diameter
*A magnet with 8 mm (or greater) diameter and 2.5 mm thickness is the recommended magnet for redundant applications.
0
300
400
500
600
700
800
900
1000
Field Strength in Gauss
Figure 3: Maximum Peak Angle Error Over Field
Strength
Different Factory Optimizations
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10
A1334
Precision Hall-Effect Angle Sensor IC
System Timing and Error
The A1334 is a digital system, and therefore takes angle samples
at a fixed sampling rate. When using a sensing device with a
fixed sampling rate to sample a continuously moving target, there
will be error introduced that can be simply calculated with the
sampling rate of the device and the speed at which the magnetic
signal is changing. In the case of the A1334, the input signal is
rotating at various speeds, and the sampling rate of the A1334 is
fixed at ANG. The calculation would be:
ANG (µs) × angular velocity ( ° / µs) .
(4)
So the faster the magnetic object is spinning, the further behind in
angle the output signal will seem for a fixed sampling rate.
0.8
25ºC
-40ºC
150ºC
0.7
Noise (Deg)
0.6
0.5
0.4
0.3
0.2
0.1
0
300
400
500
600
700
800
900
1000
Field Strength (G)
Figure 4: One Sigma Noise over Field Strength
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11
A1334
Precision Hall-Effect Angle Sensor IC
dAXIAL1
dAXIAL2
Target rotation axis
Example of equal eccentricity:
Target rotation axis
centered between both dies
Target counterclockwise
rotation
dAXIAL1 = 0
Target clockwise rotation
dAXIAL2
Example of unequal eccentricity:
Target rotation axis centered
over primary die (either die
may be used as primary)
Eccentricity of secondary die
(measured from target
rotation axis intersect,
to secondary die)
Pin 1
Figure 5: Demonstration of Magnet to Sensing Element Eccentricity
(dual die version used as example)
Angle Error vs Eccentricity
5
Average Peak Angle Error (deg)
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0
0.25
0.5
0.75
1
1.25
Eccentricity (mm)
1.5
1.75
2
Figure 6: Characteristic Performance Based on 14 Pieces
(900 G Field Strength, 8 mm Diameter Magnet)
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12
A1334
Precision Hall-Effect Angle Sensor IC
TYPICAL CHARACTERISTICS
Angle Error Vs Encoder
1
0.8
0.6
Angle Error
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
0
50
100
150
200
250
300
350
Encoder Position
Figure 7: Typical Angle Error versus Absolute Position
(300 G, 25ºC)
2
2
Mean
+/- 3 Sigma
1.6
1.6
1.4
1.4
1.2
1.2
1
0.8
0.6
1
0.8
0.6
0.4
0.4
0.2
0.2
0
-40
-20
0
20
40
60
80
100
120
Temperature (C)
Figure 8: Angle Error Over Temperature (300 G)
140
Mean
+/- 3 Sigma
1.8
Drift in Degrees
Angle Error in Degrees
1.8
0
-40
-20
0
20
40
60
80
100
120
140
Temperature (C)
Figure 9: Temperature Drift (300 G)
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13
A1334
Precision Hall-Effect Angle Sensor IC
1.0
30
150ºC
25ºC
–40ºC
25
Mean
+/- 3 Sigma
0.9
A1334 NOISE in Degrees
0.8
Frequency (%)
20
15
10
0.7
0.6
0.5
0.4
0.3
0.2
5
0.1
0
0.2
0
0.6
0.4
0
-50
1.0
0.8
Noise in Degrees
50
100
150
Ambient Temperature in Degrees C
Figure 10: Noise Distribution Over Temperature
(1σ, 300 G)
Figure 11: Noise Performance Over Temperature
(1σ, 300 G)
10
10
150ºC
25ºC
–40ºC
9
0
Mean
+/- 3 Sigma
9.5
8
9
A1334 ICC in mA
Frequency (%)
7
6
5
4
8.5
8
7.5
3
7
2
6.5
1
0
6
6.5
7
7.5
8
8.5
9
9.5
ICC in mA
Figure 12: ICC Distribution Over Temperature
(VCC = 4.5 V)
10
0
-50
0
50
100
150
Ambient Temperature in Degrees C
Figure 13: ICC Over Temperature
(VCC = 4.5 V)
Allegro MicroSystems, LLC
115 Northeast Cutoff
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14
A1334
Precision Hall-Effect Angle Sensor IC
12
10
150ºC
25ºC
–40ºC
10
Mean
+/- 3 Sigma
9.5
9
A1334 ICC in mA
Frequency (%)
8
6
8.5
8
7.5
4
7
2
0
6.5
6
6.5
7
7.5
8
8.5
9
9.5
ICC in mA
Figure 14: ICC Distribution Over Temperature
(VCC = 14.5 V)
10
0
-50
0
50
100
150
Ambient Temperature in Degrees C
Figure 15: ICC Over Temperature
(VCC = 14.5 V)
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115 Northeast Cutoff
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15
A1334
Precision Hall-Effect Angle Sensor IC
EMC Reduction
For applications with stringent EMC requirements, a 100 Ω
resistance should be added to the supply for the device in order to
suppress noise. A recommended circuit is shown in Figure 16.
VCC
0.1 µF
0.1 µF
0.1 µF
100 Ω
BYP_1
100 Ω
VCC_1 VCC_2
BYP_2
CS_1
SCLK_1
MOSI_1
MISO_1
BIAS_1
A1334
Host
Microprocessor
Target
Magnet
(Dual Die
Version)
CS_2
SCLK_2
MOSI_2
MISO_2
BIAS_2
AGND_1 AGND_2 DGND_1 DGND_2
Figure 16: Typical Application Diagram (dual die version) with EMC Suppression Resistor, RSPLY , on Supply Line
24
14
Hall element
location
Hall element
E1 location
1
Hall element
E2 location
1
Figure 17: Hall Element Located Off-Center within the Device Body
Refer to the Package Outline Drawing for reference dimensions.
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16
A1334
Precision Hall-Effect Angle Sensor IC
PACKAGE OUTLINE DRAWING
For Reference Only – Not for Tooling Use
(Reference MO-153 AB-1)
Dimensions in millimeters – NOT TO SCALE
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
5.00 ±0.10
0.45
8º
0º
D
1.63
0.65
14
14
0.20
0.09
E
2.20 D
4.40 ±0.10
1.70
6.00
6.40 BSC
0.60
+0.15
–0.10
A
1.00 REF
1
2
1
0.25 BSC
Branded Face
B
C
16X
0.10
1.10 MAX
C
2
PCB Layout Reference View
SEATING PLANE
GAUGE PLANE
SEATING
PLANE
0.30
0.19
0.15
0.00
0.65 BSC
A
Terminal #1 mark area
B
Reference land pattern layout (reference IPC7351 TSOP65P640X120-14M);
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances; when
mounting on a multilayer PCB, thermal vias at the exposed thermal pad land
can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5)
C
Branding scale and appearance at supplier discretion
D
Hall element, not to scale
E
Active Area Depth = 0.36 mm (ref)
NNNNNNNNNNNN
YYWW
LLLLLLLLLLLL
1
C
Standard Branding Reference View
N = Device part number
= Supplier emblem
Y = Last two digits of year of manufacture
W = Week of manufacture
L = Lot number
Figure 18: Package LE, 14-Pin TSSOP (Single Die Version)
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
17
A1334
Precision Hall-Effect Angle Sensor IC
For Reference Only – Not for Tooling Use
(Reference MO-153 AD)
Dimensions in millimeters – NOT TO SCALE
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
7.80 ±0.10
D
D
3.40
1.00
0.45
8º
0º
0.65
24
24
0.20
0.09
E
E2 D
D E1
4.40 ±0.10 6.40 BSC
2.20 D
6.10
+0.15
0.60 –0.10
A
1.00 REF
1.65
1
2
1
0.25 BSC
24X
B
2
PCB Layout Reference View
C
1.10 MAX
0.10 C
SEATING
PLANE
0.30
0.19
SEATING PLANE
GAUGE PLANE
0.65 BSC
0.15
0.05
A
Terminal #1 mark area
B
Reference land pattern layout (reference IPC7351 TSOP65P640X120-25M);
all pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances; when
mounting on a multilayer PCB, thermal vias can improve thermal dissipation
(reference EIA/JEDEC Standard JESD51-5)
NNNNNNNNNN
YYWW
LLLLLLLLLL
1
C
C
Branding scale and appearance at supplier discretion
D
Hall elements (E1, E2), corresponding to respective die; not to scale
E
Active Area Depth 0.36 mm REF
Standard Branding Reference View
N = Device part number
= Supplier emblem
Y = Last two digits of year of manufacture
W = Week of manufacture
L = Lot number
Figure 19: Package LE, 24-Pin TSSOP (Dual Die Version)
Allegro MicroSystems, LLC
115 Northeast Cutoff
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18
A1334
Precision Hall-Effect Angle Sensor IC
Revision History
Revision
Date
–
October 23, 2014
Description
1
December 16, 2014
2
February 17, 2015
3
June 2, 2015
Updated Selection Guide, revised EC table, Magnetic Target Requirements section, Figure 3, and added
new Figure 4
4
July 27, 2015
Updated Figure 3 on page 10
Initial Release
Revised EC table and Selection Guide to support dual die release; added Typical Chracteristics graphs
Revised Title and Terminal List Table, added footnotes to EC table
Copyright ©2010-2015, Allegro MicroSystems, LLC
Allegro MicroSystems, LLC reserves the right to make, from time to time, such departures from the detail specifications as may be required to
permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that
the information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of
Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its
use; nor for any infringement of patents or other rights of third parties which may result from its use.
For the latest version of this document, visit our website:
www.allegromicro.com
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115 Northeast Cutoff
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1.508.853.5000; www.allegromicro.com
19
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