High Sensitivity Low Power TMR Switch
Position Sensing > LF11115TMR
TMR Bipolar Switch 17 Gauss 200nA Push Pull Sensor
Description
The LF11115TMR TMR Switch is a digital bipolar magnetic switch that integrates
TMR and CMOS technology in order to provide a magnetically triggered digital
switch with high sensitivity, high speed, and low power consumption.
It contains a TMR magnetic sensor and CMOS signal processing circuitry within
the same package, including an on-chip TMR voltage generator for precise
magnetic sensing, a TMR voltage amplifier and comparator plus a Schmitt
trigger to provide switching hysteresis for noise rejection, CMOS push-pull
output and X axis sensing direction.
An internal band gap regulator is used to provide a temperature compensated
supply voltage for internal circuits, permitting a wide range of supply voltages.
It draws only 200nA (see Features below) resulting in low power operation,
additionally it has fast response, accurate switching points, excellent thermal
stability, and immunity to stray field interference. It is available in the SOT23-3
package. The output of the LF11115TMR switches low (turns on) when the
magnetic field parallel to the sensing axis exceeds the operate point threshold,
B
OP
. When the magnetic field is reduced below the release point B
RP
device
output switches high (turns off). The difference between the B
OP
and the B
RP
is
the hysteresis B
H
of the device.
Latch
Functional Block Diagram
Vcc
Power regulator
with temperature
compensation
TMR
Sensor
Offset
cancellation
Vout
Features
• Tunneling Magnetoresistance (TMR)
technology
• Ultra low power consumption at
200nA
• X axis sensing direction
• High frequency up to 50Hz
• Operation with north and south pole
• 1.8V to 5.5V operating range
GND
TMR Switch Typical Applications Circuit
Vcc
Benefits
• Low switching points for high
sensitivity
• Excellent thermal stability
• High tolerance to external magnetic
field interference
• Wider airgap capability
• Operates with smaller magnets for
cost reduction
• RoHS compliant
Vcc
0.1µF
TMR
Out
Out
Applications
• Proximity detection
• Utility meters including gas and
water meters
• Speed sensing
• Battery powered applications
• Rotary sensing
GND
Output Behavior Versus Magnetic Pole
GND
Note: It is strongly recommended that an external bypass capacitor be connected in-close-
proximity to the device between the supply and ground pins to reduce noise. The recommended
value for the external bypass capacitor is 0.1μF.
Parameter
South Pole
North Pole
Test Conditions
B > B
OPS
0 < B < B
RPS
Output (volts)
Low (On)
High (Off)
Note:
The output is “High” when power is turned on under zero magnetic field.
When a S Pole approaches the pin 1 side, V
out
will transition to Low.
When a N Pole approaches the pin 1 side, V
out
will transition to High
© 2020 Littelfuse
Revised: 02/20/20
Specifications are subject to change without notice.
littelfuse.com
High Sensitivity Low Power TMR Switch
Position Sensing > LF11115TMR
Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified)
Symbol
V
CC
V
RCC
I
OUTSINK
B
V
ESD
T
A
T
stg
Characteristics
Supply Voltage
Reverse Supply Voltage
Output Current
Magnetic Flux Density
ESD level(HBM)
Operating Temperature
Storage Temperature
Values
7.0
0.3
9.0
4000
4
-40 ~ 125
-50 ~ 150
Unit
V
V
mA
Gauss
kV
°C
°C
Note: Stresses greater than the ‘Absolute Maximum Ratings’ specified above may cause permanent damage to the device. These are stress ratings only; functional operation of the device at these or any
other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time.
Electrical Characteristics (@TA = +25°C, Vcc = 3.0V)
Symbol
V
CC
V
OH
V
OL
I
CC
Freq
Characteristics
Supply Voltage
Output High Voltage
Output Low Voltage
Supply Current
Response Frequency
Min.
1.8
Vcc -0.3
Typ.
3
Max.
5.5
Unit
V
V
Conditions
Operating
0.2
200
50
V
nA
Hz
Output Open
Magnetic Characteristics (@TA = +25°C, Vcc = 3.0V)
Symbol
B
OP
B
RP
B
H
Characteristics
Operation Point
Release Point
Hysteresis
Min.
9
-25
Typ.
17
-17
34
Max.
25
-9
Unit
Gauss
Gauss
Gauss
© 2020 Littelfuse
Revised: 02/20/20
Specifications are subject to change without notice.
littelfuse.com
High Sensitivity Low Power TMR Switch
Position Sensing > LF11115TMR
Pin Configuration and Sensing Direction of Magnetic Field
V
OUT
V
OH
SOT23-3
GND
3
Part Marking Code
B
H
ExxxY
V
OL
1
Vcc
2
V
OUT
N Pole
B
RP
0
B
OP
+B
S Pole
Part Marking Code:
Exxxy: E = LF11115TMR; xxx = Julian manufactured date; y = manufactured year
Moisture Sensitivity Level: Rating is 3
Pick and Place Nozzle: Samsung CN140 or equivalent
Magnetic Flux
Pin Name
V
OUT
GND
V
CC
Pin No. SOT23-3
2
3
1
Pin Function
Output
Ground
Supply Voltage
Part Numbering System
LF - X - X - X - X - X TMR
Littelfuse Brand
Switch Type
Type 1 = Bipolar
2 = Omnipolar
3 = Unipolar
Output
1 = PushPull
2 = Open Drain
Quiescent Current
1 = 200nA
2 = 1.5uA
3 = 0.6mA
Example: LF11115 is Bipolar, Push Pull, 200nA, X axis, 17Gauss
Note: Every combination is NOT offered. Contact Littelfuse for availability.
Tunneling
Magnetoresistance
Technology Switch
Sensitivity Gauss
1 = 5 Gauss
2 = 7 Gauss
3 = 10 Gauss
4 = 14 Gauss
5 = 17 Gauss
Sensing Axis
1 = X axis
2 = Y axis
3 = Z axis
© 2020 Littelfuse
Revised: 02/20/20
Specifications are subject to change without notice.
littelfuse.com
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