A1334A-DS
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
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-on-
chip (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.
Packages: Not to scale
A1334 Functional Block Diagram A1334 in Electronic Power Steering (EPS)
Application
Multisegment
CVH Element Analog Front End
To all internal circuits
Bandpass
Filter
Digital Processing
Temperature
Compensation
Internal Calibration
Zero Angle
Data
Registers
EEPROM
Calibration
Parameters
SPI
Interface
Diagnostics
BYP(1) SoC die 1
SoC die 2 (optional)
VCC(1)
MOSI(1)
SCLK(1)
MISO(1)
GND(1)
xxx2
ADC
BIAS(1)
CS(1)
(Programming)
Pin number parentheses refer to chip in dual SoC variant
Control unit
Rack
Motor
Steering
sensor
Single SoC
14-pin TSSOP (LE package)
Dual Independent SoCs
24-pin TSSOP (LE package)
• 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
FEATURES AND BENEFITS DESCRIPTION
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
2
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Unit
Forward Supply Voltage VCC Not sampling angles 26.5 V
Reverse Supply Voltage VRCC Not sampling angles –18 V
All Other Pins Forward Voltage VIN 5.5 V
All Other Pins Reverse Voltage VR0.5 V
Operating Ambient Temperature TAL range –40 to 150 ºC
Maximum Junction Temperature TJ(max) 165 ºC
Storage Temperature Tstg –65 to 170 ºC
Selection Guide
Part Number System Die Package Packing*
A1334LLETR-T Single 14-pin TSSOP 4000 pieces per 13-in. reel
A1334LLETR-DD-T** Dual 24-pin TSSOP 4000 pieces per 13-in. reel
*Contact Allegro™ for additional packing options.
**Contact factory for availability.
SPECIFICATIONS
Thermal Characteristics may require derating at maximum conditions, see application information
Characteristic Symbol Test Conditions* Value Unit
Package Thermal Resistance RθJA
LE-14 package 82 ºC/W
LE-24 package 117 ºC/W
*Additional thermal information available on the Allegro website.
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
3
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
VCC
A1334
VCC_1
SCLK_1
SCLK_2
MISO_1
MOSI_1
MOSI_2
MISO_2
BYP_1 VCC_2 BYP_2
BIAS_2
BIAS_1
AGND_2
AGND_1 DGND_2
DGND_1
0.1 µF
0.1 µF 0.1 µF
Host
Microprocessor
CS_1
CS_2
Target
Magnet
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.)
Terminal List Table
PinName Pin Number Function
LE-14 LE-24
AGND_1 4, 7, 9 4, 6 Device analog ground terminal
AGND_2 – 16, 18 Device analog ground terminal
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)
CS_2 – 11 SPI Chip Select terminal, active low (die 2)
DGND_1 1, 3, 14 1, 3, 24 Device digital ground terminal
DGND_2 – 12, 13, 15 Device digital ground terminal
MISO_1 10 20 SPI Master Input / Slave Output (die 1)
MISO_2 – 8 SPI Master Input / Slave Output (die 2)
MOSI_1 12 22 SPI Master Output / Slave Input (die 1)
MOSI_2 – 10 SPI Master Output / Slave Input (die 2)
SCLK_1 11 21 SPI Clock terminal (die 1)
SCLK_2 – 9 SPI Clock terminal (die 2)
VCC_1 5, 6 5 Power supply; also used for EEPROM programming
VCC_2 – 17 Power supply; also used for EEPROM programming
BIAS_1 8 19 Bias connection; connect to ground (shown) or pull-up to 3.3 V
BIAS_2 – 7 Bias connection; connect to ground (shown) or pull-up to 3.3 V
Pin-out Diagrams and Terminal List Table
DGND_1
BYP_1
DGND_1
AGND_1
VCC_1
AGND_1
BIAS_2
MISO_2
SCLK_2
MOSI_2
CS_2
DGND_2
DGND_1
CS_1
MOSI_1
SCLK_1
MISO_1
BIAS_1
AGND_2
VCC_2
AGND_2
DGND_2
BYP_2
DGND_2
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
LE-14 Package
(Single SoC)
LE-24 Package
(Dual SoC)
DGND
BYP
DGND
AGND
VCC
VCC
AGND
1
2
3
4
5
6
7
14
13
12
11
10
9
8
DGND
CS
MOSI
SCLK
MISO
AGND
BIAS
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
4
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Continued on the next page…
OPERATING CHARACTERISTICS: valid over the full operating voltage and ambient temperature ranges; unless otherwise
noted
Characteristics Symbol Test Conditions Min. Typ.1Max. Unit2
Electrical Characteristics
Supply Voltage VCC 4.5 12 14.5 V
Supply Current ICC Each die, A1334 sampling angles – – 10 mA
Undervoltage Lockout Threshold
Voltage3
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
VCC Low Flag Threshold4,5 VUVLOTH 4.35 4.5 4.75 V
Supply Zener Clamp Voltage VZSUP ICC = ICC + 3 mA, TA = 25°C 26.5 – – V
Reverse Battery Current IRCC VRCC = –18 V, TA = 25°C –5 – – mA
Power-On Time6,8 tPO – 300 – µs
Bypass Pin Output Voltage VBYP TA = 25°C, CBYP = 0.1 µF 2.5 2.85 3.2 V
SPI Interface Specications
Digital Input High Voltage8VIH MOSIx, SCLKx,
¯
C
¯
¯
S
¯
x pins 2.8 – 3.63 V
Digital Input Low Voltage8VIL MOSIx, SCLKx,
¯
C
¯
¯
S
¯
x pins – – 0.5 V
SPI Output High Voltage VOH MISOx pins, CL = 50 pF, TA = 25°C 2.93 3.3 3.69 V
SPI Output Low Voltage VOL MISOx pins, CL = 50 pF, TA = 25°C – 0.3 0.5 V
SPI Clock Frequency8fSCLK MISOx pins, CL = 50 pF 0.1 – 10 MHz
SPI Frame Rate8tSPI 5.8 – 588 kHz
Chip Select to First SCLK Edge8tCS
Time from
¯
C
¯
¯
S
¯
x going low to SCLKx falling
edge 50 – – ns
Data Output Valid Time8tDAV Data output valid after SCLKx falling edge – 40 – ns
MOSI Setup Time8tSU Input setup time before SCLKx rising edge 25 – – ns
MOSI Hold Time8tHD Input hold time after SCLKx rising edge 50 – – ns
SCLK to CS Hold Time8tCHD
Hold SCLKx high time before
¯
C
¯
¯
S
¯
x rising
edge 5 – – ns
Load Capacitance8CLLoading on digital output (MISOx) pin – – 50 pF
Magnetic Characteristics
Magnetic Field9B Range of input field 300 – 1000 G
Missing Magnet Flag MAGM 100 – G
Angle Characteristics
Output10 RESANGLE – 12 – bit
Effective resolution11 B = 300 G, TA = 25ºC, ORATE = 0 – 9.2 – bits
Angle Refresh Rate12,13 tANG
High RPM mode – 25 – µs
Low RPM mode, AVG = 011 (varies
with AVG mode, refer to the appendix
Programming Reference)
– 200 – µs
Response Time tRESPONSE High RPM mode (see figure 4) – 60 – µs
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
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Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
OPERATING CHARACTERISTICS (continued): valid over the full operating voltage and ambient temperature ranges; un-
less otherwise noted
Characteristics Symbol Test Conditions Min. Typ.1Max. Unit2
Angle Characteristics (continued)
Angle Error14 ERRANG
TA = 25°C, ideal magnet alignment, B = 300
G, target rpm = 0 – ±0.6 – deg.
TA = 150°C, ideal magnet alignment, B =
300 G, target rpm = 0 –1.75 – 1.75 deg
Angle Noise15 NANG
TA = 25°C, B = 300 G, no internal filtering – 0.6 – deg.
TA = 150°C, no internal filtering, B = 300 G,
target rpm = 0 – 0.8 – deg.
Temperature Drift ANGLEDRIFT
TA = -40°C, B = 300 G – ±1.5 – deg.
TA = 150°C, B = 300 G –1.5 – –1.5 deg.
Angle Drift over Lifetime16 ANGLEDRIFT-
LIFE
B = 300 G, typical maximum drift observed
after AEC-Q100 qualification testing – ±1.0 – deg
1 Typical data is at TA = 25°C and VCC = 5 V, and it is for design estimates only.
2 1 G (gauss) = 0.1 mT (millitesla).
3 At power-on, a die will not respond to commands until VCC rises above VUVLOHI. After that, the die will perform and respond normally until VCC drops below VUVLOLOW
.
4 Characterization data shows negligible accuracy degradation at supply voltages between 4.35 V and 4.50 V. Signicant 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 specications are to aid in PCB design. The pin is not intended to drive any external circuitry.
8 Parameter is not guaranteed at nal test. Values for this characteristic are determined by design.
9 The A1334 operates in magnetic elds lower than 300 G, but with reduced accuracy and resolution.
10 RESANGLE represents the number of bits of data available for reading from the die registers.
11 Effective Resolution is calculated using the formula below:
log22
(360) - log (3 X )
32
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.
12 The rate at which a new angle reading will be ready.
13 To calculate Low RPM mode, time = 300 µs + 25 × 2AVG. Given AVG = 011 = 3 (decimal), so 23 = 8.
14 In general, Allegro’s angle sensor ICs are more accurate when stronger magnetic elds (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 applications magnetic elds.
15 Value reects 3 standard deviations.
16 After qualication 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 tem-
perature cycling), a small number of devices drifted by approximately 1 degree.
Applied Magnetic Field
Transducer Output
50
0
Angle (º)
Response Time, tRESPONSE
t
Denition of Response Time
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
6
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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 mea-
surement 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 measure-
ment 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 resolu-
tion. 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 Program-
ming 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 regard-
less 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 transmis-
sion 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 approxi-
mately 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 tim-
ing, 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
Power-up
Upon applying power to the A1334, the device automatically runs
through an initialization routine. The purpose of this initialization
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
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Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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 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.
Diagnostics
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.
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
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
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Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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.
V (V)
CC
4.5
4.0
3.8
1.5
MISO Pin
State
t
VCC Low Flag Threshold, VUVLOTH
Undervoltage Lockout Threshold
Voltage (high), VUVLOHI
DIGON
High
Impedance
Accurate
Angle Output
High
Impedance
Ground Ground
VCC Low
Flag
Set
VCC Low
Flag
Set
Output
accuracy
reduced
DIGON
Undervoltage Lockout Threshold
Voltage (Low),VUVLOLOW
Output
accuracy
reduced
Figure 1: Relationship of VCC and MISO Output
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
9
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
APPLICATION INFORMATION
Figure 2: Orientation of Magnet Relative to Primary Die and Secondary Die
(dual die version used as example)
NS
T
arget alignment for default angle setting
•T
arget 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)
Target rotation axis
Target poles aligned with
A1334 elements
E1
Pin 1 E1
E2
E2
SN
Calculating Target Zero Degree Angle
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 system
level readings are required.
The internal algorithm for computing the output angle is as
follows:
AngleOUT = AngleRAW – Reference Angle (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)
Bypass Pin Usage
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 Characteris-
tics table for output voltage and current requirements.
Changing Sampling Modes
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.
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
10
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Magnetic Target Requirements
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. Figure 3 demonstrates the perfor-
mance of an A1334 sensor, optimized for 300 G, over a variety of
field strengths. Contact Allegro for more detailed information on
magnet selection and theoretical error.
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 4 depicts two possible
alignment configurations.
Figure 5 illustrates the behavior of alignment error when using
a ø8 mm × 2.5 mm Neodymium magnet that is located 2.0 mm
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.
The curve provides guidance to determine what the optimal mag-
net 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.
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.
Table 2: Target Magnet Parameters
Magnetic Material Diameter
(mm)
Thickness
(mm)
Neodymium (bonded) 15 4
Neodymium (sintered)* 10 2.5
Neodymium (sintered) 8 2.5
Neodymium / SmCo 6 2.5
NS
Thickness
Diameter
*A sintered Neodymium magnet with 10 mm (or greater) diameter and 2.5 mm
thickness is the recommended magnet for redundant applications.
300 400
500 600 700 800 900 1000
0
0.5
1
1.5
2
2.5
3
Angle Error Over Field Strength
Sensor Optimized for 300G
Peak Angle Error (Deg)
Field Strength (G)
Figure 3: Angle Error Over Field Strength
Sensor Optimized for 300 G
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
11
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Figure 5: Characteristic Performance Based on 14 Pieces
Figure 4: Demonstration of Magnet to Sensing Element Eccentricity
(dual die version used as example)
Example of equal eccentricity:
Target rotation axis
centered between both dies
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)
Target rotation axis
Target clockwise rotation
Target counterclockwise
rotation
d
AXIAL1 dAXIAL2
d= 0
AXIAL1 dAXIAL2
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Eccentricity (mm)
Average Peak Angle Error (deg)
Angle Error vs Eccentricity
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
12
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
V
CC
A1334
(Dual Die
Version)
VCC_1
SCLK_1
SCLK_2
MISO_1
MOSI_1
MOSI_2
MISO_2
BIAS_1
BYP_1 VCC_2
AGND_1 AGND_2
BYP_2
DGND_1 DGND_2
0.1 µF
100 Ω 100 Ω
0.1 µF 0.1 µF
Host
Microprocessor
CS_1
CS_2
Target
Magnet
BIAS_2
Figure 6: Typical Application Diagram (dual die version) with EMC Suppression Resistor, RSPLY , on Supply Line
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 6.
Figure 7: Hall Element Located Off-center within the Device Body
Refer to the Package Outline Drawing for reference dimensions.
1
Hall element
E1 location
Hall element
E2 location
Hall element
location
24
1
14
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
13
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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
A
1.10 MAX
0.15
0.00
0.30
0.19
0.20
0.09
8º
0º
0.60
1.00 REF
C
SEATING
PLANE
C0.10
16X
0.65 BSC
0.25 BSC
21
14
5.00 ±0.10
4.40 ±0.10
2.20
1.63
6.40 BSC
GAUGE PLANE
SEATING PLANE
A
B
B
DE
D
Branding scale and appearance at supplier discretion
Hall element, not to scale
Active Area Depth = 0.36 mm (ref)
C
D
E
6.00
0.65
0.45
1.70
14
21
1
C
Branded Face PCB Layout Reference View
Standard Branding Reference View
= Device part number
= Supplier emblem
= Last two digits of year of manufacture
= Week of manufacture
= Lot number
N
Y
W
L
Terminal #1 mark area
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)
NNNNNNNNNNNN
YYWW
LLLLLLLLLLLL
+0.15
–0.10
Figure 8: Package LE, 14-Pin TSSOP (Single Die Version)
PACKAGE OUTLINE DRAWING
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
14
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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
A
1.10 MAX
0.15
0.05
0.30
0.19
0.20
0.09
+0.15
–0.10
8º
0º
0.60
1.00 REF
C
SEATING
PLANE
C0.10
24X
0.65 BSC
0.25 BSC
2
2
1
1
24
24
7.80 ±0.10
4.40 ±0.10
2.20
6.40 BSC
GAUGE PLANE
SEATING PLANE
A
B
B
0.65
6.10
1.65
0.45
D
D
D
D
DD
Hall elements (E1, E2), corresponding to respective die; not to scale
1.003.40
E1 E2
CBranding scale and appearance at supplier discretion
E
E
C
PCB Layout Reference View
Terminal #1 mark area
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)
Active Area Depth 0.36 mm REF
1
Standard Branding Reference View
= Device part number
= Supplier emblem
= Last two digits of year of manufacture
= Week of manufacture
= Lot number
N
Y
W
L
NNNNNNNNNN
YYWW
LLLLLLLLLL
Figure 8: Package LE, 24-Pin TSSOP (Dual Die Version)
Precision, Micro Power Hall-Effect Angle Sensor IC
A1334
15
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Copyright ©2010-2014, 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.
Revision History
Revision Date Description
– September 23, 2014 Initial Release
For the latest version of this document, visit our website:
www.allegromicro.com