ETC HMC1041Z

1-Axis Magnetic Sensor
HMC1041Z
Advanced Information
The Honeywell HMC1041Z is a z-axis surface mount option
designed for low field magnetic sensing. By adding the
HMC1041Z to other 2-axis magneto-resistive sensors, a cost
effective and space-efficient 3-axis magnetometer or
compassing solution is enabled. This compact, low cost
solution is easy to assemble for high volume, cost effective
OEM designs. Applications for the HMC1041Z include
Compassing, Navigation Systems, Magnetometry, and
Current Sensing.
The HMC1041Z utilizes Honeywell’s Anisotropic Magnetoresistive (AMR) technology that provides advantages over coil
based magnetic sensors. They are extremely sensitive, low field, solid-state magnetic sensors designed to measure
direction and magnitude of Earth’s magnetic fields, from tens of micro-gauss to 6 gauss. Honeywell’s Magnetic Sensors
are among the most sensitive and reliable low-field sensors in the industry.
Honeywell continues to maintain product excellence and performance by introducing innovative solid-state magnetic
sensor solutions. These are highly reliable, top performance products that are delivered when promised. Honeywell’s
magnetic sensor solutions provide real solutions you can count on.
FEATURES
BENEFITS
4
Low Height Magnetic Sensors (1.05mm)
Dimensions and Small Size for Low Profile Vertical Sensing
4 Narrow
Applications and Mounting, No Layout Constraints
4
Surface Mount Z-Axis Sensor
4 Easy to Assemble & Compatible with High Speed SMT Assembly
4
Low Voltage Operations (2.0V)
4 Compatible for Battery Powered Applications
4
Low Cost
4 Designed for High Volume, Cost Effective OEM Designs
4
Available in Tape & Reel Packaging
4 High Volume OEM Assembly
4
Lead Free Package Construction
4 Complies with Current Environmental Standards
4
4-Element Wheatstone Bridge
4 Low Noise Passive Element Design
4
Wide Magnetic Field Range (+/-6 Oe)
4 Sensor Can Be Used in Strong Magnetic Field Environments
4
Patented Offset and Set/Reset Straps
4 Stray Magnetic Field Compensation
HMC1041Z
SPECIFICATIONS
Characteristics
Conditions*
Min
Typ
Max
Units
Vbridge referenced to GND
2.0
5.0
20
Volts
Resistance
Bridge current = 1mA
800
1050
1300
ohms
Field Range
Full scale (FS) – total applied field
-6
+6
gauss
Sensitivity
Set/Reset Current = 0.5A
0.8
1.25
mV/V/gauss
Resolution
1 kHz bandwidth, Vbridge = 5.0 volts
Bridge Elements
Supply
1.0
0.16
milli-gauss
(RMS)
1.44
milli-gauss
(pk – pk)
Bridge Offset
Offset = (OUT+) – (OUT-)
-2.0
±0.5
+2.0
mV/V
Field = 0 gauss after Set pulse
Bandwidth
Disturbing Field
Magnetic signal (lower limit = DC)
5
Sensitivity starts to degrade.
MHz
20
gauss
10000
gauss
Use S/R pulse to restore sensitivity.
Max. Exposed
No perming effect on zero reading
Field
Operating
Ambient
-40
125
°C
Ambient, unbiased
-55
125
°C
TA= -40 to 125°C, Vbridge=5V
-3500
-2000
ppm/°C
Temperature
Storage
Temperature
Sensitivity
-3100
Tempco
Bridge Offset
Tempco
Bridge Ohmic
TA= -40 to 125°C, No Set/Reset
±500
TA= -40 to 125°C, With Set/Reset
±10
Vbridge=5V, TA= -40 to 125°C
2100
2500
ppm/°C
2900
ppm/°C
Tempco
Cross-Axis
Cross field = 0.5 gauss, Happlied = ±3 gauss
±0.5%
%FS/gauss
Sensitivity
Linearity Error
Best fit straight line
± 1 gauss
0.17
± 3 gauss
0.42
± 6 gauss
0.80
Hysteresis Error
3 sweeps across ±3 gauss
0.15
%FS
Repeatability Error
3 sweeps across ±3 gauss
0.11
%FS
8.9
milli-grams
Weight
* Tested at 25°C except stated otherwise.
2
%FS
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HMC1041Z
SPECIFICATIONS
Characteristics
Conditions*
Min
Typ
Max
Units
Measured from S/R+ to S/R-
3
5
6
ohms
0.1% duty cycle, or less,
0.4
0.5
2
Amp
TA=-40 to 125°C
3000
3900
4500
ppm/°C
Measured from OFFSET+ to OFFSET-
5
8
11
ohms
Set/Reset Strap
Resistance
Current
2µsec current pulse
Resistance
Tempco
Offset Straps
Resistance
Offset
DC Current
Constant
10
mA/gauss
Field applied in sensitive direction
Resistance
TA=-40 to 125°C
1800
2700
4500
ppm/°C
Tempco
* Tested at 25°C except stated otherwise.
Schematic Diagram
HMC1041Z
Pin Configurations
(Arrow indicates direction of applied field that generates a positive output voltage after a SET
pulse.)
Back
View
8
7
6
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5
4
3
2
1
Pin Number
1
2
3
4
5
6
7
8
Function
OFFSETVbridge
OFFSET+
OUT+
OUTGND
S/RS/R+
3
HMC1041Z
PACKAGE OUTLINES
PACKAGE DRAWING HMC1041Z (8-PIN LPCC, dimensions in millimeters)
41 - 00
D
Front
View
E
Bottom
View
A
Pin 1
e
b
L
Dimension
D
E
A
b
L
e
Min
0.95
4.00
0.91
0.17
0.37
Millimeters
Nom
1.05
4.10
1.08
0.20
0.40
0.5 basic
Max
1.15
4.20
1.25
0.23
0.43
Back
View
Mounting Considerations
The following is the recommend printed circuit board (PCB) footprint for the HMC1041Z. The two small (0.5mm by 0.5mm)
leveling pads are to hold the part square to the PCB and should receive the same pad finish as the rest of the pads but
without additional solder paste. The goal is to hold the part vertical surfaces perpendicular to the board surface. All
dimensions are nominal and in millimeters.
Back
View
Side
View
0.40
0.20
Pin Contact
0.50
0.50
0.30
Solder
Filet
Pin 1
No Paste
Pad
Pad
0.60
Bottom
View
1.05
0.50
0.50
4
1.75
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HMC1041Z
Stencil Design and Solder Paste
A 4 mil stencil and 100% paste coverage is recommended for the eight electrical contact pads. Do not apply paste on the
leveling pads. The HMC1041Z has been tested successfully with no-clean solder paste.
Pick and Place
Placement is machine dependant and no restrictions are recommended, and have be tested with mechanical centering.
Placement force should be equivalent 1206 SMT resistors and enough force should be used to squeeze the paste out
from the package/contact pad overlap and to keep the package pin contacts vertical. The low mass of the HMC1041Z
ensures that very little paste is required to hold the part until reflow.
Reflow and Rework
No special profile is required for the HMC1041Z, and compatible with lead eutectic and lead-free solder paste reflow
profiles. Honeywell recommends the adherence to solder paste manufacturer’s guidelines. The HMC1041Z may be
reworked with soldering irons, but extreme care must be taken not to overheat the copper pads from the part’s fiberglass
substrate. Irons with a tip temperature no greater than 315°C should be used. Excessive rework risks the copper pads
pulling away into the molten solder.
Basic Device Operation
The Honeywell HMC1041Z magnetoresistive sensor is a Wheatstone bridge device to measure magnetic fields. With
power supply applied to a bridge, the sensor converts any incident magnetic field in the sensitive axis direction to a
differential voltage output. In addition to the bridge circuit, the sensor has two on-chip magnetically coupled straps; the
offset strap and the set/reset strap. These straps are Honeywell patented features for incident field adjustment and
magnetic domain alignment; and eliminate the need for external coils positioned around the sensors.
The magnetoresistive sensors are made of a nickel-iron (Permalloy) thin-film deposited on a silicon wafer and patterned
as a resistive strip element. In the presence of a magnetic field, a change in the bridge resistive elements causes a
corresponding change in voltage across the bridge outputs.
These resistive elements are aligned together to have a common sensitive axis (indicated by arrows on the pinouts) that
will provide positive voltage change with magnetic fields increasing in the sensitive direction. Because the output only is in
proportion to the one-dimensional axis (the principle of anisotropy) and its magnitude, additional sensor bridges placed at
orthogonal directions permit accurate measurement of arbitrary field direction. The combination of sensor bridges in two
and three orthogonal axis permit applications such as compassing and magnetometry.
The offset strap allows for several modes of operation when a direct current is driven through it. These modes are: 1)
Subtraction (bucking) of an unwanted external magnetic field, 2) null-ing of the bridge offset voltage, 3) Closed loop field
cancellation, and 4) Auto-calibration of bridge gain.
The set/reset strap can be pulsed with high currents for the following benefits: 1) Enable the sensor to perform high
sensitivity measurements, 2) Flip the polarity of the bridge output voltage, and 3) Periodically used to improve linearity,
lower cross-axis effects, and temperature effects.
Offset Strap
The offset strap is a spiral of metallization that couples in the sensor element’s sensitive axis. The offset strap measures
nominally 8 ohms, and requires 10mA for each gauss of induced field. The straps will easily handle currents to buck or
boost fields through the ±6 gauss linear measurement range, but designers should note the extreme thermal heating on
the die when doing so.
With most applications, the offset strap is not utilized and can be ignored. Designers can leave one or both strap
connections (Off- and Off+) open circuited, or ground one connection node. Do not tie both strap connections together to
avoid shorted turn magnetic circuits.
Set/Reset Strap
The set/reset strap is another spiral of metallization that couples to the sensor elements easy axis (perpendicular to the
sensitive axis on the sensor die. Each set/reset strap has a nominal resistance of 5 ohms with a nominal required peak
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5
HMC1041Z
current of 500mA for reset or set pulses. With rare exception, the set/reset strap must be used to periodically condition the
magnetic domains of the magneto-resistive elements for best and reliable performance.
A set pulse is defined as a positive pulse current entering the S/R+ strap connection. The successful result would be the
magnetic domains aligned in a forward easy-axis direction so that the sensor bridge’s polarity is a positive slope with
positive fields on the sensitive axis result in positive voltages across the bridge output connections.
A reset pulse is defined as a negative pulse current entering the S/R+ strap connection. The successful result would be
the magnetic domains aligned in a reverse easy-axis direction so that sensor bridge’s polarity is a negative slope with
positive fields on the sensitive axis result in negative voltages across the bridge output connections.
Typically a reset pulse is sent first, followed by a set pulse a few milliseconds later. By shoving the magnetic domains in
completely opposite directions, any prior magnetic disturbances are likely to be completely erased by the duet of pulses.
For simpler circuits with less critical requirements for noise and accuracy, a single polarity pulse circuit may be employed
(all sets or all resets). With these uni-polar pulses, several pulses together become close in performance to a set/reset
pulse circuit. Figure 1 shows a quick and dirty manual pulse circuit for uni-polar application of pulses to the set/reset strap.
Iset
5 volts
Rsr
3.0
Figure 1
Manual Set Pulse Circuit
Ordering Information
Ordering Number
Product
HMC1041Z
One Axis Magnetic Sensor
HMC1041Z T/R 3k
Tape and Reel 3k pieces/reel
HMC1041Z Cut Tape
Cut Tape
Find out more
For more information on Honeywell’s Magnetic Sensors visit us online at www.magneticsensors.com or contact us at
800-323-8295 (763-954-2474 internationally).
The application circuits herein constitute typical usage and interface of Honeywell product. Honeywell does not warranty or assume liability of customerdesigned circuits derived from this description or depiction.
Honeywell reserves the right to make changes to improve reliability, function or design. Honeywell does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
U.S. Patents 4,441,072, 4,533,872, 4,569,742, 4,681,812, 4,847,584 and 6,529,114 apply to the technology described
Aerospace Electronics Systems
Defense and Space Electronics Systems
Honeywell International Inc.
12001 Highway 55
Plymouth, MN 55441
Tel: 800-323-8295
www.honeywell.com
6
Form #900314
April 2005
©2005 Honeywell International Inc.
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