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GT Sensors
Precision Gear Tooth and Encoder Sensors
NVE’s GT Sensor products are based on a Low Hysteresis GMR sensor material and are designed
for use in industrial speed applications where magnetic detection of gear teeth and magnetic encoder
wheels is required.
GT Sensors with both analog and digital outputs are available. The analog parts feature the large signal
and robust characteristics which NVE’s GMR materials are known for (NVE’s GMR sensors are not
damaged by extremely large magnetic fields). The sensor elements themselves are designed to provide
usable output with even the smallest gear teeth. Single and double output versions are available; the
second output is phase shifted with respect to the first, to provide quadrature for determining direction.
The digital sensors take advantage of the high
performance characteristics of GMR sensors to
provide a 50% duty cycle output with a wide
tolerance in airgap and temperature variations.
GT Sensors are available in low-profile MSOP8,
TDFN SO8, and TDFN6 packages, in order to
fit into the tightest possible spaces. An
evaluation kit is available, containing a selection
of sensors, magnets, and PCBs, so that the user
can test the parts in their application
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ABL Sensors
Single/Double Bridge Gear Tooth And Encoder Sensors
Features:
• Large Airgap
• Direct Analog Output
• DC (Zero Speed) Operation
• Sine / Cosine Outputs
• Precise Spacing and Phase Shifting Between Sensor Elements
• Excellent Temperature and Volt a ge Perf o rmance
• Small, Low-Profile Surface Mount Packages
Applications:
• Linear and Angular Speed Sensing
• Linear and Angular Positio n Sensing
• Direction Detection
Description:
The ABL-Series GT Sensors are differential sensor elements that provide an analog sinusoidal output
signal when used with a bias magnet and gear tooth or a magnetic encoder. These chips use NVE’s
proprietary GMR sensor elements featuring an extremely large output signal from the raw sensor
element, which is stable over the rated temperature and voltage range. As a result, ABL-Series GT
Sensors feature excellent airgap performance and an extremely stable operating envelope as well as the
robust reliability characteristics that NVE sensors are known for.
Three different standard spacings are available for use with fine and coarse pitch encoders and gear
teeth. Both single bridge and double bridge configurations are also available. Double bridges are used
to generate sine/cosine outputs. In addition to the standard spacings, NVE can provide custom sp acings
and multiple sensor elements tailored to the individual customer’s application for a nominal design and
tooling charge. Contact NVE for further details.
For digital output applications, these sensors can be used with NVE’s DD001-12 signal processing IC
which converts their output into a 50% duty cycle modulated current signal. This IC allows placement
of the ABL sensor in a very small housing with wires running from the sensor to the signal processing
IC in a remote location. Thus ABL-Series sensors can be used in M8 and smaller housings.
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Specifications:
Parameter Min Typ Max Unit
Single Bridge Resistance at 25°C 4K 5K 7K Ohms
Input Voltage <11 301 Volts
Operating Temperature Range -50 +150 °C
Offset Voltage -4 +4 mV/V
Linear Range ±5 ±100 Oe
Linearity of Output 98 %2
Hysteresis 2 %2
Saturation of GMR Sensor Elements -180 +180 Oe3
Single Resistor Sensitivity .04 %∆R/Oe4
Max Output 80 mV/V
Temperature Coefficient of Resistance +0.11 %/°C
ESD 400 V5
Storage Temperature Range -65 +170 °C
Notes:
1. ABL-Series sensors have a purely ratiometric output. They will operate with input volta ges of 0.1 V or lowe r. The output
signal will scale proportionally with the input voltage. Maximum voltage will be limited by the power dissipati on
allowable in the package and user installation. See the package section for more details.
2. Linearity and Hysteresis measured across linear operating range, unipolar operation.
3. Application of a magnetic field in excess of this value will saturate the GMR sensor elements and no further output will be
obtained. No damage occurs to the sensor elements when saturated. NVE GMR sensors will not be damaged by any large
magnetic field.
4. Percent change in resistance with application of 1 Oersted of magnetic field; corresponds to an 8% change in resistance
with 200 Oersteds of applied magneti c fiel d (1 Oersted = 1 Gauss in air, or 0.1 milliTesla).
5. Pin-to-pin voltage , Huma n B od y M o del fo r ESD.
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IC Drawings:
0.250
1.000
1.000
0.5000.250
0.1250.125
0.500
0.500
0.250
1.000 0.500
0.5000.250
- All dimensions in mm
- All resistors are 5kΩ
- Sensor elements are located symmetrically about the center of the IC.
0.125
0.140
Center of Die
and Package
ABL014
ABL015
ABL004
ABL005
Note: ABL006 ABL016 Sensor Element Size and Spacing Not Shown
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Schematics:
Part Numbers and Configurations:
Part Number Single or Dual
Bridge
Element
Spacing
(Microns)
Phase Shift
Between
Bridges
(Microns) Package
Marking
ABL004-00 Single 1000 NA FDB
ABL005-00 Single 500 NA FDC
ABL006-00 Single 300 NA FDL
ABL014-00 Dual 1000 500 FDD
ABL015-00 Dual 500 250 FDF
ABL016-00 Dual 300 150 FDM
ABL004-10 Single 1000 NA FDG
ABL005-10 Single 500 NA FDH
ABL006-10 Single 300 NA FDN
ABL014-10 Dual 1000 500 FDJ
ABL015-10 Dual 500 250 FDK
ABL016-10 Dual 300 150 FDP
R2
R1
OUT+
GND
VCC
OUT-
R4
R3
ABL004, ABL005, ABL006
Schematic
R2
R1
OUT+1
GND1
VCC1
OUT-1
R4
R3 R6
R5
OUT+2
GND2
VCC2
OUT-2
R8
R7
ABL014, ABL015, ABL016
Schematic
(Dual Bridge)
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Packages:
The ABL-Series parts are available in MSOP8 and TDFN6 packages. Please see the package drawing
section in the Appendix for dimensions. Please note that for dual differential sensors in the TDFN
package the power and ground connections for both bridges are common.
Pin Configuration:
MSOP8 Package
TDFN6 Package
Direction of Sensitivity
ABL004-00,
ABL005-00,
ABL006-00
Out+
No Connect
Ground
VCC
Out-
No Connect No Connect
No Connect ABL014-00,
ABL015-00,
ABL016-00
Ground1
Out-1
VCC1
VCC2
Ground2
Out+1 Out-2
Out+2
Direction of Sensitivity
ABL004-10,
ABL005-10,
ABL006-10
Out+
Gnd
VCC
Out-
No Connect No Connect ABL014-10,
ABL015-10,
Ground1,
Ground2
Out+1
VCC1
VCC2
Out-2
Out-1 Out+2
ABL006-10 ABL016-10
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AKL Sensors
Digital Output Gear Tooth And Encoder Sensors
Features:
• Large Airgap
• 50% Duty Cycle
• DC (Zero Speed) Operation
• Precise Spacing Between Sensor Elements
• Excellent Temperature and Volt a ge Perf o rmance
• Small, Low-Profile Surface Mount Package
Applications:
• Anti-lock Brake System Sensors
• Transmission Speed Sensors
• Industrial Linear and Angular Speed Sensing
• Linear and Angular Positio n Sens ing
Description:
NVE offers these products specifically for use as sensors for gear tooth wheels or magnetic encoders
with a digital output signal. The pulse output from the sensor corresponds with the gear teeth passing
in front of it. When a gear tooth or magnetic pole is in front of the sensor, the sensor’s output goes
high; when the gear tooth or magnetic pole moves away, the output returns to low. This repeats at
every tooth/pole resulting in a pulse train output that provides speed information from the gear or
encoder. Three part numbers are currently available: the AKL001-12 is designed for gear teeth or
encoders with a pitch of 2.5 to 6 mm, the AKL002-12 for a pitch of 1 to 2.5 mm, and the AKL003-12
for a pitch of 0.6 t o 1. 5 m m.
In order to minimize the number of wires leading to the sensor, the part is configured as a two-wire
device. The two output states are indicated with a change of current through the part. Therefore, when
the part is in the dig ital low state, current is about 3 mA. When th e part is in the digital high state, the
current increases to about 10 mA. If necessary, the two-wire output of the AKL-Series parts can be
easily converted to a three-wire current sinking output with the circuit shown in the GT Sensor
applications section.
The parts are rated for the full automotive and industrial temperature range, -40°C to +150°C. They
feature reverse battery protection and have an operational voltage range of 4.5V to 36V. They operate
from DC to 10 kHz. The parts are available in low-profile, surface mount TDFN SO8 packages.
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Specifications:
Parameter Min Typ Max Unit
Input Voltage 4.5 36 Volts1
Supply Current in Off State
(Input Voltage=12V) 3.2 4.0 4.8 mA2
Supply Current in On State
(Input Voltage=12V) 7.0 8.0 9.0 mA2
Output Duty Cycle 40 50 60 %
Operating Temperature Range -40 +150 °C
AKL001-12 Airgap, Over Full Temperature and
Voltage Range4 1.0 3.5 mm
AKL002-12 Airgap, Over Full Temperature and
Voltage Range4 1.0 2.5 mm
AKL003-12 Airgap, Over Full Temperature and
Voltage Range4 1.0 2.0 mm
Frequency of Operation 0 10K Hz
ESD 2000 V3
Absolute Maximum Ratings
Parameter Limit
Supply Voltage 45V
Reverse Battery Voltage -60V
Continuous Output Current 16mA
Junction Temperature Range -40°C to +170°C
Storage Temperature Range -65°C to +170°C
Notes:
1. The supply voltage must appear across the power and ground terminals of the part. Any additional voltage drop due to the
presence of a series resistor is not included in this specification.
2. Supply currents can be factory progra mm ed to different levels, for exam ple 3 mA and 6 mA, or 7 mA and 14 mA;
contact NVE for details.
3. Pin-to-pin voltage , Huma n B od y M o del fo r ESD
4. Airgap measured with standard ferrous gear tooth; contact NVE for details.
Current
Output
(mA)
Time
5
10
Signal Output
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IC Drawings:
The AKL-Series products use the ABL sensor elements described earlier in this section. The AKL001-
12 part uses the ABL004 sensor element, the AKL002-12 uses the ABL005 sensor element, and the
AKL003-12 uses the ABL006 sensor element. Please see the IC drawings in the ABL-Series section
for more information.
Part Numbers and Configurations:
Part Number Single or Dual
Bridge
Element
Spacing
(Microns) Marking
AKL001-12 Single 1000 Part Number
AKL002-12 Single 500 Part Number
AKL003-12 Single 300 Part Number
Schematic:
A block diagram of the AKL-Series part s is sh ow n bel o w:
Packages:
The AKL-Series parts are available in the TDFN8 SO8 package. Please see the package drawing
section in the Appendix for di mensi o ns.
Voltage
Regulator
GMR
Bridge
EEPROM
Offset
Detector
Gain
Switching
Current
Source
Current Level
A
A
3.3V
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Pin Configuration:
TDFN8-SO8 Package
TEST
TEST
VCC
GND
BRIDGE-
TEST
TEST
BRIDGE+
AKL001-12
AKL002-12
AKL003-12
Sensitivity
Note: Bridge + and Bridge - are provided for
analysis purposes only. NVE does not
recommend connecting these pins in a
production product for ESD and loading
reasons. Also, all pins labeled “Test” must be
floating, i.e., not connected to each other or
any other circuit node.
