Sensing and Productivity Solutions
Datasheet
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
DESCRIPTION
Honeywell’s Magnetoresistive Sensor ICs (integrated circuits),
Standard Power Series, are ultra-sensitive devices designed
for manufacturers who need a durable and reliable speed or
position sensor for large air gaps or small magnetic fields in
standard power (typically 3 Vdc to 24 Vdc) applications. Unlike
reed switches and other magnetic sensors, Honeywell’s solid
state design offers ultra-high sensitivity of 11 G max., making it
the highest sensitivity sensor in its class for standard powered
applications. The Magnetoresistive Sensor ICs, Standard Power
Series, respond to either a North or South pole applied in a
direction parallel to the sensor. They do not require the magnet
polarity to be identified, simplifying installation and potentially
reducing system cost.
VALUE TO CUSTOMERS
• Durable and reliable due to magnetic solid state, non-contact,
no-glass design which enhance switching capability.
• Cost-effective and flexible due to the sensor IC’s ultra-high
sensitivity—the highest sensitivity sensor in its class for
standard powered applications—which lowers the customer’s
cost of magnets and simplifies design-in.
• Simplifies design-in for wired applications due to its supply
voltage range, omnipolar operation, SOT-23 and flat TO-92-
style package options and wide operating temperature range.
DIFFERENTIATION
• Ultra-high sensitivity (SM351RT and SM451R) allows for
potential use in applications requiring ultra-high magnetic
sensitivity (7 G typical operate, 11 G maximum operate).
32304118
Issue C
SM351RT
SM353RT
SM451R
SM453R
FEATURES
• Magnetic sensitivities:
- Ultra-high sensitivity (SM351RT and SM451R): For
applications requiring ultra-high magnetic sensitivity
(7 G typical operate, 11 G maximum operate)
- Very high sensitivity (SM353RT and SM453R): For
applications requiring very high magnetic sensitivity
(14 G typical operate, 20 G maximum operate)
• Package styles:
- SOT-23 (SM351RT, SM353RT)
- Flat TO-92-style (SM451R, SM453R)
• Supply voltage range 3 Vdc to 24 Vdc
• Omnipolar sensing activates with either pole from a magnet
• Temperature range -40 °C to 85 °C [-40 °F to 185 °F]
• SOT-23 supplied on tape and reel (3000 units per reel)
• RoHS-compliant materials meet Directive 2002/95/EC
POTENTIAL APPLICATIONS
Industrial
• High frequency flow sensing in HVAC, water, fuel meters,
and gas utility meters
• Anti-tamper detection in water, electric, and gas utility
meters
• Liquid level detection
• Motor RPM sensing
• In-cylinder position sensing
Medical
• RPM sensing in exercise and rehabilitation equipment
• Magnetic interrupt in exercise and rehabilitation equipment
• Absence/presence detection in infusion pumps
• Position sensing of medication dispensing cabinet drawers
• Incline position sensing in hospital beds
White Goods
• Lid, door and drawer position detection
• Fluid flow detection
• Liquid level detection
PORTFOLIO
Honeywell’s Standard Power Series join:
• Magnetoresistive sensor ICs, including the Nanopower
Series, 2SS52M Series, SS552MT Series
• Hall-effect sensor ICs, including the SS351A, SS451A
2Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Table 1. Electrical Specifications (3 V < Vcc < 24 V, -40 °C < Ta < 85 °C [-40 °F < Ta < 185 °F] unless otherwise specified.)
CCharacteristic Condition Min. Typ. Max. Unit
Supply voltage (Vcc) Vcc reference to ground 312 24 V
Supply current:
off
on
—
Vcc = 5 V, T = 25 °C [77 °F]
Vcc = 5 V, T = 25 °C [77 °F
—
—
2.5
4
8
3.5
5
mA
Start-up time Vcc > 3 V — — 10 µs
Output leakage current Vcc = 24, off — — 10 µA
Output saturation voltage load current = 20 mA — — 500 mV
Rise time
Fall time
Vcc = 5 V, R = 2 kOhm, C = 20 pF
Vcc = 5 V, R = 2 kOhm, C = 20 pF
—
—
—
—
1.5
1.5 µs
NOTICE
Absolute maximum ratings are the extreme limits that the device will withstand without damage to the
device. However, the electrical and mechanical characteristics are not guaranteed as the maximum limits
(above recommended operating conditions) are approached, nor will the device necessarily operate at
absolute maximum ratings.
Table 3. Absolute Maximum Ratings
C Characteristic Condition Min. Typ. Max. Unit
Operating temperature ambient -40 [-40] —85 [185] °C [°F]
Soldering temperature:
SM351RT, SM353RT
SM451R, SM453R
ambient applied for < 10 s
ambient applied for < 3 s
—
—
—
—
245 [473]
260 [500]
°C [°F]
Supply voltage (Vs) —-26 —26 V
Load current output sinking (open collector) — — 40 mA
NOTICE
The magnetic field strength (Gauss) required to cause the switch
to change state (operate and release) will be as specified in the
magnetic characteristics. To test the switch against the specified
magnetic characteristics, the switch must be placed in a uniform
magnetic field.
NOTICE
These magnetoresistive sensor ICs may have an initial output in
either the ON or OFF state if powered up with an applied magnetic
field in the differential zone (applied magnetic field >Brp and
<Bop). Honeywell recommends allowing 10 μs for output voltage
to stabilize after supply voltage has reached its final rated value.
Table 2. Magnetic Specifications (3 V < Vcc < 24 V, -40 °C < Ta < 85 °C [-40 °F < Ta < 185 °F].)
Characteristic Min. Typ. Max. Unit
SM351RT, SM451R:
operate (positive)
release (positive)
differential
3
2
—
7
4.8
2.2
11
9
—
Gauss
SM353RT, SM453R:
operate (positive)
release (positive)
differential
6
3
—
14
9.3
5.7
20
18
—
Gauss
CAUTION
ELECTROSTATIC
SENSITIVE
DEVICES
DO NOT OPEN OR HANDLE
EXCEPT AT A
STAT IC FREE WORKSTAT ION
ESD SENSITIVITY:
CLASS 3A
3
Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Figure 2. Block/Electrical Diagram
Figure 1. Typical Magnetic Performance versus Temperature
SM351RT, SM451R
SM353RT, SM453R
AMR
Sensor
Trigger
circuit
and
amplier
Output (O
)
Vcc (+)
Gnd (-)
Magnetic Switch Point (Gauss)
0
1
2
3
4
5
-40
[-40] -20
[-4] 0
[32] 20
[68] 40
[104] 60
[140] 80
[176]
6
7
8
9
10
Release Gauss
Operate Gauss
Temperature (°C [°F])
Differential Gauss
Differential Gauss
Magnetic Switch Point (Gauss)
0.0
2.0
4.0
6.0
8.0
10.0
-40
[-40] -20
[-4] 0
[32] 20
[68] 40
[104] 60
[140] 80
[176]
12.0
14.0
16.0
18.0
Release Gauss
Operate Gauss
Temperature (°C [°F])
4Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Figure 3. Alignment of the Magnet to the SOT-23 Package (SM351RT, SM353RT) Omnipolar Magnetoresistive Sensor IC
Ideal alignment: The magnet is aligned in the same plane as the sensor IC.
Offset alignment: The magnet is not aligned in the same plane as the sensor IC.
SM351RT,
SM353RT
Sensor IC
Magnet
Magnet movement
Magnet
SM351RT,
SM353RT
Sensor IC
Magnet movement
Magnet
The sensor IC detects the approaching magnet’s horizontal magnetic flux lines, turning the sensor IC to ON. The sensor IC stays
ON as the magnet continues to approach. When the magnet is located directly over the sensor IC, all magnetic flux lines are now
horizontal (see Figure 3.C). (Note: This alignment decreases the magnetic flux strength at the sensor IC.)
The magnetic flux lines stay horizontal as the magnet
approaches the sensor IC (see Figure 3.A).
Dead zones may occur when the majority of the magnet’s
magnetic flux lines become vertical as it approaches the
sensor IC, turning the sensor IC ON, then OFF, then ON
(see Figure 3.B).
Perpendicular magnet approach to the sensor IC eliminates possible dead
zones.
Parallel magnet approach to the sensor IC may cause dead zones.
Figure 3.A
Figure 3.B
Figure 3.C
Magnet
SM351RT,
SM353RT
Sensor IC
Magnet movement
end view
top view
5
Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Figure 4. Alignment of the Magnet to the TO-92-Style Package (SM451R, SM453R) Omnipolar Magnetoresistive Sensor IC
Ideal alignment: The magnet is aligned in the same plane as the sensor IC.
Offset alignment: The magnet is not aligned in the same plane as the sensor IC.
Magnet
Magnet movement
SM451R,
SM453R
Sensor IC
end view
top view
Magnet movement
Magnet
SM451R,
SM453R
Sensor IC
SM451R,
SM453R
Sensor IC
Magnet movement
Magnet
The sensor IC detects the approaching magnet’s horizontal magnetic flux lines, turning the sensor IC to ON. The sensor IC stays
ON as the magnet continues to approach. When the magnet is located directly over the sensor IC, all magnetic flux lines are now
horizontal (see Figure 4.C). (Note: This alignment decreases the magnetic flux strength at the sensor IC.)
The magnetic flux lines stay horizontal
as the magnet approaches the sensor
IC (see Figure 4.A).
Dead zones may occur when the majority
of the magnet’s magnetic flux lines become
vertical as it approaches the sensor IC,
turning the sensor IC ON, then OFF, then
ON (see Figure 4.B).
Perpendicular magnet approach to the sensor IC eliminates possible dead zones.
Parallel magnet approach to the sensor IC may cause dead zones.
Figure 4.A
Figure 4.B
Figure 4.C
6Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Figure 5. SM351RT and SM353RT Sensor IC, Tape and Reel Mounting Dimensions (For reference only. mm/[in].) E
0,20
[0.008]
1,40
[0.055]
0,061
[0.002]
3,15
[0.124]
3,20
[0.125]
1,5
[0.059]
2,00
[0.079]
4,00
[0.157]
4,00
[0.157]
8,0
[0.315]
1,75
[0.069]
3,50
[0.138]
1,00 MIN.
[0.039]
TOP
COVER
TAPE
Section A-A
A
A
60,0
[2.362]
10,9
[0.429]
14,4
[0.567]
8,40
[0.331]
40,0
[1.57]
4,00
[0.157]
10
[0.394]
20,2
[0.795]
2,0
[0.079]
13,0
[0.512]
178
[7.000]
MEASURED
AT HUB
MEASURED
AT HUB
MEASURED
AT OUTER
EDGE
MIN.
MAX.
Reel
Tape
Sensor IC Sensor IC Showing Polarity
3
GND
(-)
2,90
[0.114]
1
VCC
(+)
2
OUTPUT
1,20
[0.047]
0,77
[0.030]
0,60
[0.024]
0,787
[0.031]
0,413
[0.016]
1,90
[0.075]
0,95
[0.037]
3X 0,40 TYP.
[0.016]
2,80
[0.110]1,60
[0.063]
NOMINAL TO AMR
EFFECT SENSING
SURFACE
61
61
or
0,15
[0.006]
TO CENTERLINE OF
AML ELEMENT
0,15
[0.006]
NOMINAL TO
IC CENTER
1,40 MAX.
[0.110]
7
Sensing and Productivity Solutions
Magnetoresistive Sensor ICs
Standard Power Series: SM351RT, SM451R, SM353RT, SM453R
Table 4. Order Guide
Catalog Listing Description
SM351RT
Magnetoresistive sensor IC, ultra-high sensitivity (7 G typ.), standard
power, SOT-23 package, pocket tape and reel packaging (3000 units
per reel)
SM353RT
Magnetoresistive sensor IC, very high sensitivity (14 G typ.), standard
power, SOT-23 package, pocket tape and reel packaging (3000 units
per reel)
SM451R Magnetoresistive sensor IC, ultra-high sensitivity (7 G typ.), standard
power, flat TO-92-style package, bulk packaging (1000 units per bag)
SM453R Magnetoresistive sensor IC, very high sensitivity (14 G typ.), standard
power, flat TO-92-style package, bulk packaging (1000 units per bag)
3X 0,38
[0.015]
3
GND
(-)
1
VCC
(+) 2
OUTPUT
1,89
[0.074]
IC SENSING
SURFACE
[0.016]
3X 0,38
[0.015]
0,75
[0.003]
1,52
[0.06]
2,50
[0.10]
3X 0,56 MAX.
[0.02]
2X 1,27 MAX.
[0.02]
3,00
[0.12]
14,5
[0.57]
61
61
or
Figure 6. SM451R and SM453R Mounting Dimensions (For reference only. mm/[in].)
Sensor IC Showing Polarity
Sensor IC
Find out more
Honeywell serves its customers through
a worldwide network of sales offices,
representatives and distributors.
For application assistance, current
specifications, pricing or name of the
nearest Authorized Distributor, contact
your local sales office.
To learn more about Honeywell Sensing
and Productivity Solutions’ products, call
+1-815-235-6847 or 1-800-537-6945,
visit sensing.honeywell.com, or e-mail
inquiries to info.sc@honeywell.com
Sensing and Productivity Solutions
Honeywell
1985 Douglas Drive North
Golden Valley, MN 55422
honeywell.com
Warranty/Remedy
Honeywell warrants goods of its manufacture as being free
of defective materials and faulty workmanship. Honeywell’s
standard product warranty applies unless agreed to
otherwise by Honeywell in writing; please refer to your order
acknowledgement or consult your local sales office for specific
warranty details. If warranted goods are returned to Honeywell
during the period of coverage, Honeywell will repair or replace,
at its option, without charge those items it finds defective.
The foregoing is buyer’s sole remedy and is in lieu of all
other warranties, expressed or implied, including those of
merchantability and fitness for a particular purpose. In no
event shall Honeywell be liable for consequential, special, or
indirect damages.
While we provide application assistance personally, through our
literature and the Honeywell web site, it is up to the customer to
determine the suitability of the product in the application.
Specifications may change without notice. The information we
supply is believed to be accurate and reliable as of this printing.
However, we assume no responsibility for its use.
WARNING
PERSONAL INJURY
DO NOT USE these products as safety or emergency stop
devices or in any other application where failure of the product
could result in personal injury.
Failure to comply with these instructions could result in
death or serious injury.
WARNING
MISUSE OF DOCUMENTATION
• The information presented in this datasheet is for reference
only. Do not use this document as a product installation
guide.
• Complete installation, operation, and maintenance
information is provided in the instructions supplied with each
product.
Failure to comply with these instructions could result in
death or serious injury.
32304118-C-EN IL50
January 2016
© 2016 Honeywell International Inc. All rights reserved.
ADDITIONAL INFORMATION
The following associated literature is available on the Honeywell
web site at sensing.honeywell.com:
• Product Installation Instructions
• Product Aplication Note
• Magnetic Sensors Line Guide
• Position Sensors Range guide
• Magnetic Sensors Selection Chart
• Magnetic Sensors Line Card