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Technologies & Products Press Conference 2014
Superior TMR angle sensing for automotive
systems
Martin Appel
Electronic Components Sales & Marketing Group
November 12, 2014
Rising requirements for automotive angle
measurement
Applications
Throttle
valve
Wipers
Steering
(EPS motor)
Accuracy of
conventional
products
Future
requirements
±2° to ±3°
±1°
±0.6°
±1.2°
(20 to 130 mT) (20 to 130 mT)
±0.6°
(20 to 80 mT)
±0.3°
(20 to 80 mT)
Redundancy
ISO 26262
Needed: The accuracy of angle measurements
in automotive applications must be doubled!
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 2
Evolution of magneto resistive sensor technologies
MR ratio
[%]
Output
[mV]
SNR
@ 10 kHz
[dB]
Output
shift from
25 °C to
125 °C [%]
AMR
3
90
72
-29
GMR
12
360
77
-23
TMR
100
3000
96
-13
AMR
Free layer
GMR
Free layer
Shunt layer
Pin layer
TMR
Current
Free layer
Barrier layer
Pin layer
Current
Current
TMR output
• more than 30 times higher than AMR
• 8 times higher than GMR
• smaller thermal coefficient factor
for a broad temperature range
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 3
Steering – the most demanding angle sensor
application
EPS motor
2-pole magnet
TMR angle sensor
EPS system
Steering
angle
sensor
TMR sensor is positioned on the opposite side of a 2-pole magnet.
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 4
Superior performance of TDK TMR angle sensors
Output waveform
1.6
AMR sin
GMR sin
TMR sin
AMR cos
GMR cos
TMR cos
• Higher output
3.0 Vpp @ 5 V (30x AMR, 8x GMR)
1.2
TMR
Output [V]
0.8
GMR
AMR
0.4
0
• Greater angle accuracy
Angle accuracy of less than ±0.6°
over a wide range of magnetic field
strengths and temperatures
(20 mT to 80 mT, -40 °C to 150 °C)
-0.4
• Lower power consumption
5 mW under recommended
operating conditions
-0.8
-1.2
-1.6
0
90
180
Angle [°]
270
360
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 5
TMR angle sensors for automotive applications
TAS2004
TAS4501
• 2 x 2 directions
• 4 full bridges
• Redundancy (ISO 26262)
• 2 directions
• 2 full bridges
Output
Package
ATAS2001
•
•
•
•
2 directions
2 full bridges
plus ASIC
Redundancy (ISO 26262)
Analog
Analog
Digital
TSSOP8
VSOP16
SSOP16
6.40 mm
1
1
V Sin
4
Cos
Cos-
Sin+
V Cos
G Sin
Cos+
8
5
8
Dimensions
3.0 x 4.4 x 1.1 mm
G1 Cos
V1 Sin
Cos1-
Sin1+
G1 Sin
V1 Cos
Sin2-
G2 Cos
16
4.40 mm
Cos1+
V2 Sin
Cos2-
Sin2+
V2 Cos
G2 Sin
Cos2+
5.00 mm
Pin
configuration
Sin-
Sin1-
ASIC
9
5.1 x 4.4 x 1.15 mm
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
6.4 x 5.0 x 1.15 mm
© TDK 2014
CC • 11/14 • 6
TAS2004: 2 directions, 2 full bridges, analog
• Four output waveforms (sin+, sin-, cos+, cos-) are created
when the 2-pole magnet rotates
• Angle accuracy of less than ±0.6° @ 20 mT to 80 mT and -40 °C to 150 °C
• TSSOP8 package (3.0 mm x 4.4 mm x 1.1 mm)
Circuit
Output waveform
8
7
6
5
N
S
S
N
S
N
V
Cos
sin-
sin+
Cos+
G
S
1
G
Output [V]
V
N
S
N
Ch 1 (sin)
0
Ch 2 (cos)
-1
1
2
3
4
0
90
180
270
360
Angle [°]
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 7
TAS4501: 2x 2 directions, 4 full bridges, analog
• 8 output waveforms (2x sin+, sin-, cos+, cos-) are created
when the 2-pole magnet rotates
• Angle accuracy of less than ±0.6° @ 20 mT to 80 mT and -40 °C to 150 °C
• VSOP16 package (5.1 mm x 4.4 mm x 1.15 mm)
Circuit
Output waveform
sin 1
16
15
cos 1
14
13
sin 2
12
cos 2
11
10
N
S
S
N
S
N
N
9
S
S
N
1
sin+
V
V
Cos
sin-
sin+
Cos
sin-
Cos+
G
sin 1
V
Cos+
G
G
G
Output [V]
V
cos 1
0
sin 2
cos 2
-1
1
2
3
4
5
6
7
8
0
90
180
270
360
Angle [°]
TAS4501 angle sensor offers redundancy in a single component.
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 8
ATAS2001 includes ASIC for digital output
High-precision digital angle sensor with signal
conditioning and redundancy in a single component
and support for ISO 26262
Features
6.40 mm
4.40 mm
5.00 mm
ASIC
•
•
•
•
•
•
•
•
•
High output based on TMR technology
Angle accuracy of ≤ ±0.2° in auto-calibration mode
High SNR
Minimal drift over wide temperature range
of -40 °C to +150 °C
Magnetic field range of 20 mT to 80 mT
Error compensation mode
Digital output for all standard protocols
14-bit A/D converter
SSOP16 package (6.4 mm x 5.0 mm x 1.15 mm)
Error compensation significantly improves angle measurement accuracy.
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 9
Customer benefits of TDK’s TMR angle sensors
• Highest measurement accuracy
• Sensor ouput many times higher
than conventional products
• Very small temperature drift over a
broad range of magnetic field strengths
• Low power consumption
• Redundancy available in a single
component
• TDK supports ISO 26262 requirements
Superior performance
Technologies & Products Press Conference 2014 • Superior TMR angle sensing for automotive systems
© TDK 2014
CC • 11/14 • 10
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