ALLEGRO ATS645LSH

ATS645LSH
Preliminary – Subject to Change
True Zero Speed
Miniature Gear Tooth Sensor
PRELIMINARY DATASHEET
(subject to change without notice)
The ATS645LSH is an optimized Hall effect sensing integrated
circuit and magnet combination that provides a user-friendly
solution for true zero-speed digital gear-tooth sensing in two-wire
applications. The sensor consists of a single-shot molded plastic
package that includes a samarium cobalt magnet, a pole piece, and
a Hall effect IC that has been optimized to the magnetic circuit.
This small package can be easily assembled and used in
conjunction with a wide variety of gear shapes and sizes.
The integrated circuit incorporates a dual element Hall effect
sensor and signal processing that switches in response to
differential magnetic signals created by ferrous gear teeth. The
circuitry contains a sophisticated digital circuit to eliminate magnet
and system offsets and to achieve true zero speed operation (ref
U.S. Patent 5,917,320). A-D and D-A converters are used to adjust
the device gain at power up and to allow air gap independent
switching.
Pin 1: Supply
Pin 2: No connection
Pin 3: Test pin
Pin 4: Ground
ABSOLUTE MAXIMUM RATINGS
Supply Voltage,
VCC . . . . . . . . . . . . . . . . . . . . . . . . . 26.5 V*
Reverse Supply Voltage,
VR . . . . . . . . . . . . . . . . . . . . . . . . . . . . –18 V
Operating Temperature Range,
TA . . . . . . . . . . . . . . . . . –40 °C to 150 °C*
Storage Temperature,
TS . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 °C
Package Power Rating,
ϑ JA . . . . . . . . . . . . . . . . . . . . . . . . 126 °C/W
Maximum Junction Temperature,
TJmax . . . . . . . . . . . . . . . . . . . . . 165 °C
* Operation at increased supply voltages with external
circuitry is described in the Applications Information.
ATS645LSH-DS Rev. 1
The regulated current output is configured for two wire
applications and the sensor is ideally suited for obtaining speed and
duty cycle in ABS and transmission application gear-tooth-based
configurations.
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
s
s
Fully optimized differential digital gear tooth sensor
Single chip sensing IC for high reliability
Internal current regulator for 2 wire operation
Small mechanical size (8 mm dia x 5.5 mm length)
Air gap independent switch points
Digital output representing gear profile
Precise duty cycle signal with temperature
Large operating air gaps
Automatic Gain Control (AGC)
Automatic Offset Adjustment circuit
True zero speed operation
Under-voltage lockout
Wide operating voltage range
Defined power-on state
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
CHARACTERISTICS
Valid over operating temperature range and Supply Voltage within specification unless otherwise noted.
Characteristics
Symbol
Limits
Test Conditions
Min.
Typ.
Max.
Units
24
V
ELECTRICAL CHARACTERISTICS
Supply Voltage
VCC
Operating, TJ < 165°C
4.0
VCC(UV)
VCC 0 → 5 V
-
-
<Vcc Min
V
VZ
IZT = 1 mA
28
32
-
V
Max Zener Pulse Current
IZ
t=20mS Pulse Mode
-
-
50
mA
Supply Zener Resistance
RZ
-
50
-
Ω
Supply Current
ATS645LSH – I1
ICC
Low Current State: IccLow
4.0
6
8.0
mA
High Current State: IccHigh
12.0
14.0
16.0
mA
Supply Current
ATS645LSH – I2
ICC
Low Current State: IccLow
5.9
7
8.4
mA
High Current State: IccHigh
11.8
14.0
16.8
mA
SPO
VCC 0 → 5 V
-
IccHigh
-
-
ton
Gear speed < 100 rpm
-
1
2
ms
IR
IccHigh à IccLow, IccLow à IccHigh,
RS = 100 Ω, CS = 10 pF, 10 to 90%
Under Voltage Lockout
1
Supply Zener Clamp Voltage
POWER-ON STATE CHARACTERISTICS
Power-On State
2
Power-On Time
OUTPUT STAGE
Output Current Slew Rate
10
1
mA/µs
The zener is tested using a pulse method and is designed for transient protection, continuous operation may destroy the device.
Power On Time is the time required to complete internal offset adjust. It does not include automatic gain control, which requires
three tooth valley transitions to complete and is therefore RPM dependent.
2
Revision 1.2; MHN; 07.Aug.02
Page 2 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Operating Characteristics: Valid with Reference Target unless otherwise specified
Characteristics
Symbol
Limits
Test Conditions
Min.
Typ.
Max.
Units
8K
RPM
SWITCH POINT CHARACTERISTICS
Rotation Speed
Smax
Using Reference Target over Operating
Air Gap Range
0
Analog Signal Bandwidth
f-3db
-3dB Point
20
40
1
Bop
-
100
150
mV
1
Brp
-
100
150
mV
3
Edges
60
G
Operate Point
Release Point
IccHigh à IccLow
Positive Peak referenced, AG < AGmax
IccLow à IccHigh
Negative Peak referenced, AG < AGmax
KHz
Calibration
Initial Calibration
CI
Number of Rising Mechanical Edges for
Accurate Edge Detection
DAC Characteristics
Output switching only; may not meet
data sheet specifications
Allowable User Induced
Differential Offset
-60
SWITCH POINT DETAIL
Bop
Input
Differential
Signal
Brp
Device
Output
Current
Pin 3 Differential Signal (not magnetic signal)
1
Bop and Brp should be adjustable with metal mask changes, limits max air gap but improves vibration immunity.
Revision 1.2; MHN; 07.Aug.02
Page 3 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Operating Characteristics:
Valid only if magnetic offset is within the Dynamic Offset Compensation DAC Range as specified above
Characteristics
Symbol
Limits
Test Conditions
Min.
Typ.
Max.
Units
OPERATING CHARACTERISTICS: Using Reference Target and Valid Over Operating Temperature Range
1
Operational Air Gap Range
Switching Air Gap Range
OpAG
OpMaxAG
Duty Cycle Variation
DC
2
Sig
3
SigMin
Operating Signal Range
Minimum Operating Signal
Duty cycle within specification
Output Switching: Duty cycle Not in
Specification
Wobble < 0.5mm
Typical value at 1.5mm air gap
Valid over operating air gap range
Duty cycle within Specification
Wobble < 0.5mm
Output Switching: Duty Cycle Not in
Specification
0.5
2.75
mm
3
-
-
mm
37
53
57
%
30
-
1000
G
20
-
-
G
1
Operating air gap is dependent on the available magnetic field. The available field is target geometry and materiel
dependent and should be independently characterized. The field available from the reference target is given in the
reference gear parameter section of the datasheet
2
In order to remain in specification the magnetic signal must be larger than the minimum value specified, this includes the
effect of target wobble.
3
Duty cycle is not guaranteed to be in specification. Reference the Duty Cycle vs. Air Gap Over Temperature graph in
the typical operating characteristics section of this document.
Revision 1.2; MHN; 07.Aug.02
Page 4 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Reference Gear Parameters
REFERENCE GEAR DIMENSIONS (60-0)
Diameter
Gd
-
120
-
mm
Thickness
Gt
-
6
-
mm
Tooth Width
Tw
-
3
-
mm
Valley Width
Vw
-
3
-
mm
Valley Depth
Vd
-
3
-
mm
Materiel
Low Carbon Steel
Target Description:
Tooth Width: 3.25mm
Diameter: 120mm
Valley Width: 3.10mm
Tooth Thickness: 6mm
Valley Depth: 3mm
Flux Density vs. Position
Reference Target
300
250
200
Flux Density (Gauss)
150
100
50
0.94mm
1.19mm
1.44mm
1.69mm
1.94mm
2.19mm
2.44mm
2.69mm
2.94mm
3.19mm
3.44mm
3.69mm
0
-50
-100
-150
-200
-250
-300
244
246
248
250
252
254
Position (º)
256
258
260
262
Reference Target Peak to Peak vs. Air Gap
500
450
400
P-P [Gauss]
350
300
250
200
150
100
50
0
0.75
Revision 1.2; MHN; 07.Aug.02
Page 5 of 12
1
1.25
1.5
1.75
2
2.25
2.5
Air Gap [mm]
2.75
3
3.25
3.5
3.75
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Typical Operating Characteristics: Duty Cycle vs. Air Gap Over Temperature
Duty Cycle vs. Air Gap
Allegro MicroSystems, Inc. Standard Production 60-0 Target
ATS645LSH @ 1000RPM
65
Typical @ 25ºC
Typical @ 150ºC
Typical @ -40ºC
Duty Cycle (%)
60
55
50
45
40
35
0.5
0.75
1
1.25
1.5
1.75
2
2.25
2.5
2.75
3
3.25
Air Gap (mm)
Figure #1: Duty Cycle vs. Air Gap Over Temperature with Reference Target and Orientation Given in Figure #2
ROTATION RIGHT is CW from pin 4 to pin 1
Figure #2: Sensor Orientation and Direction of Rotation of Reference Target for Duty Cycle
Graph in Figure #1
Revision 1.2; MHN; 07.Aug.02
Page 6 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
SENSOR DESCRIPTION
Assembly Description:
The ATS645LSH true zero speed gear tooth sensor is a Hall IC/magnet configuration that is fully optimized to provide
digital detection of gear tooth edges. This sensor is integrally molded into a plastic body that has been optimized for size,
ease of assembly, and manufacturability. High operating temperature materials are used in all aspects of construction.
Sensing Technology:
The gear tooth sensor sub-assembly contains a single-chip differential Hall effect sensor IC, a Samarium Cobalt magnet,
and a flat ferrous pole piece. The Hall IC consists of 2 Hall elements spaced 1.5 mm apart that measure the magnetic
gradient created by the passing of a ferrous object. The two elements measure the magnetic gradient and convert it to an
analog voltage that is then processed to provide a digital output signal.
Revision 1.2; MHN; 07.Aug.02
Page 7 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Transient Performance per ISO 7637-1
at TA = 23 ±5°C
(Tested at Allegro test facility – for engineering reference only)
Pulse No.
Test
I
1
2
3a
3b
4
5
6
7
Inductive turn off (negative)
Inductive turn off (positive)
Capacitive/inductive coupling (neg)
Capacitive/inductive coupling (pos)
Reverse battery
Load dumb
Ignition coil disconnect
Field decay (negative)
A
-
Performance Class at Test Level
II
III
C
-
C
C
-
IV
C
A
A
A
A
E
E
C
UA = 13.5V for pulses 1, 2, 3a, 3b, 5, 6, 7 and 12V for pulse 4.
Test Circuit #1
Performance Class Definitions
PCB Ouline by Dashed Line
(for transient performance and EMC performance)
Icc
A – All functions of a device perform as designed during and
after the exposure.
Pin #1
Pin #2
VEMC
645
Pin #3
0.01uF
Pin #4
100Ohm
Pins #2 and #3 Floating
ECU
Transient & EMC test circuit
Power supply voltage transients, or device output short circuits,
may be caused by faulty connectors, crimped wiring
harnesses, or service errors. The prevent catastrophic failure,
internal protection against over-voltage, reverse voltage, and
output overloads have been incorporated to meet the
automotive 12 volt system protection requirements of ISO
DP7637/1. A series-blocking diode or current-limiting resistor
is required in order to survive pulse number six.
Revision 1.2; MHN; 07.Aug.02
Page 8 of 12
B – All functions of a device perform as designed during
exposure; however, one or more of them may go beyond the
specified limit tolerance. All functions return automatically to
within normal limits after exposure is removed. Memory must
remain Class A.
C – One or more functions of the device do not perform as
designed during exposure but return automatically to normal
operation after exposure is removed.
D – One or more functions of the device do not perform as
designed during exposure and do not return to normal
operation until exposure is removed and the device is reset by
simple “ operator” action.
E – One or more functions of the device do not perform as
designed during and after the exposure and cannot be
returned to proper operation without repairing or replacing the
device.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
ELECTROMAGNETIC COMPATIBILITY (EMC) PERFORMANCE
at TA = 23 ±5°C
(Tested at Allegro test facility – for engineering reference only)
TEM Cell Performance per ISO 11452-3
Test severity level
I = 50 V/m
II = 100 V/m
III = 150 V/m
IV = 200 V/m
Frequency Band
(MHz)
F1 (0.01 to 10)
F2 (0 to 30)
F3 (30 to 80)
F4 (80 to 200)
Performance Class at Test Level
II
III
I
–
–
–
–
–
–
–
–
–
–
A
B
IV
A
A
A
B
BCI per ISO 11452-4
Test severity level
I = 25 mA
II = 50 mA
III = 75 mA
IV = 100 mA
Frequency Band
(MHz)
F1 (1 to 10)
F2 (10 to 30)
F3 (30 to 80)
F4 (80 to 200)
F5 (200 to 400)
Performance Class at Test Level
II
III
I
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
IV
A
A
A
A
A
Direct RF per ISO 11452-7
Test severity level
I = 100 mW
II = 200 mW
III = 300 mW
IV = 400 mW
V = 500 mW
Frequency Band
(MHz)
F1 (1 to 10)
F2 (10 to 30)
F3 (30 to 80)
F4 (80 to 200)
F5 (200 to 400)
Revision 1.2; MHN; 07.Aug.02
Page 9 of 12
I
II
Performance Class at Test Level
III
IV
V
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
MECHANICAL INFORMATION
1
2
Component
Material
Function
Value
Sensor Package
Material
Thermoset Epoxy
Max. Temperature
170°C
Leads
Copper, 0.016” dia, 0.050” spacing
Lead Coating
Solder, Tin / Lead 90/10
1
2
Temperature excursions of up to 225°C for 2 minutes or less are permitted.
Industry accepted soldering techniques are acceptable for this sub-assembly as long as the indicated maximum
temperatures for each component are not exceeded.
DEVICE QUALIFICATION PROGRAM
Test Name
High Temperature
Operating Life
Test Conditions
AEC-Q100 #2 (JA108)
Ta = 150°C, Tj = 165°C
AEC-Q100 #3 (JA103)
High Temperature Bake
Ta = 170°C
Temperature Humidity
AEC-Q100 #5 (JA101)
Bias
85°C/85%RH
Autoclave
AEC-Q100 #6 (JA102)
Test Length # of Lots Sample / lot
408 hrs
1
77
1000 hrs
1
77
1008 hrs
1
77
96 hrs
1
77
500 cycles
1
Temperature Cycling
AEC-Q100 #7(JA104)
ESD
AEC-Q100 #20 (AEC-Q100002, AEC-Q100-003)
-
1
Early Life Failure Rate
AEC-Q100 #25 (AEC-Q100008)
150°C/24 hrs
1
Revision 1.2; MHN; 07.Aug.02
Page 10 of 12
Comments
-65°C to +160°C, 30 sec.
transition, 30 minute dwell
Passes ±6kV all pin
3/model/step combinations: Human
Body Model
77
800
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
Functional block diagram
Vcc/Output
Hall AMP
+
AGC
INTERNAL
REGURATOR
Auto Offset
Control
Offset DAC
Track DAC
AGC DAC
Peak Hold
V Neg
Test Pin
Test signals
Typical Application Circuit
PCB Ouline by Dashed Line
Icc
Pin #1
Pin #2
Pin #3
VSupply
645
0.01uF
Pins #2 and #3 Floating
Revision 1.2; MHN; 07.Aug.02
Page 11 of 12
ECU
100Ohm
Pin #4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.
ATS645LSH – Preliminary – Allegro Confidential
TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR
SENSOR PACKAGE
LSH PACKAGE
REFERENCE DIMENSIONS ONLY
Revision 1.2; MHN; 07.Aug.02
Page 12 of 12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1993, 1995 Allegro MicroSystems, Inc.