0632
DISCONTINUED PRODUCT
Replaced by
ATS672LSB-LN
Always order by complete part number, e.g., ATS632LSA .
ZERO-SPEED, SELF-CALIBRATING,
NON-ORIENTED, HALL-EFFECT GEAR-TOOTH SENSOR
Data Sheet
27627.125
Dwg. AH-006-2
1
2
3
4
Pin 1 = Supply
Pin 2 = Output
Pin 3 = Test Point
Pin 4 = Ground
The ATS632LSA gear-tooth sensor is an optimized Hall-effect IC/
magnet combination that provides extremely accurate tooth edge
detection when used with large-pitch targets. The sensor module
consists of a high-temperature plastic shell that holds together a
compound samarium-cobalt magnet and a single-element self-calibrat-
ing Hall-effect IC that has been optimized to the magnetic circuit. This
small package, with its non-oriented operation, can be easily as-
sembled on a PC board for complete protection and used in conjunc-
tion with a number of gear configurations.
The gear sensing technology used for this sensor is Hall-effect
based. The sensor incorporates a single-element Hall IC that switches
in response to absolute magnetic signals created by a ferrous target.
The digital output is LOW over a tooth and HIGH over a valley. The
sophisticated processing circuitry contains self-calibrating 6-bit A/D
circuitry that adapts the thresholds to the peak-to-peak signals to
minimize the effects of variation in application air gap on switch-point
timing accuracy. The effects of system and device offsets are mini-
mized by using active offset cancellation circuitry. The digital algorithm
provides zero-speed detection capabilities without the associated
running jitter inherent in classical digital solutions.
This sensor system is ideal for use in gathering speed, position
and profile information of ferrous objects. They are particularly suited
to large tooth/valley sensing applications where accurate timing
accuracy is a desired feature. For applications requiring the sensing of
fine-pitch gears, the ATS610LSA and ATS611LSB are recommended.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
......................... 24 V*
Reverse Supply Voltage, V
RCC
........ -24 V
Output OFF Voltage, V
OUT
................. 25 V
Output Current, I
OUT
.. Internally Limited
Reverse Output Current, I
OUT
........ 50 mA
Package Power Dissipation,
P
D
.................................... See Graph
Operating Temperature Range,
T
A
............................ -40
C to +150
C
Storage Temperature, T
S
............ +170
C
* Operation at increased supply voltages with
external circuitry is described in Applications
Information.
ATS632LSA
continued next page...
PRELIMINARY INFORMATION
(subject to change without notice)
August 28, 2002
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
ATS632LSA
HALL-EFFECT
GEAR-TOOTH SENSOR
2
FEATURES AND BENEFITS
s
Non-Oriented Installation
s
Fully Optimized Gear-Tooth Sensors
s
Zero-Speed Digital Output Representing Target
Profile
s
Large Operating Air Gaps
s
Extremely Low Timing Accuracy Drift with Tempera-
ture
s
Correct First-Edge Detection
s
Self-Calibrating Circuitry
with Integrated Offset Cancellation
6-bit A/D Converters to Capture Peaks
Thresholds Proportional to Peak-to-Peak Signals
s
Optimized Magnetic Circuit
s
Single-Chip Sensing IC for High Reliability
FUNCTIONAL BLOCK DIAGRAM
600
400
200
40
80
120
160
0
AMBIENT TEMPERATURE IN
C
ALLOWABLE PACKAGE POWER DISSIPATION IN mW
Dwg. GH-065-1
60
100
140
180
20
800
1000
R
JA
= 147
C/W
TEST
POINT
3
X
REFERENCE
GENERATOR
THRESHOLD
PEAK
CURRENT
LIMIT
REG
NEGATIVE PEAK
TRACK & HOLD
POSITIVE PEAK
TRACK & HOLD
POWER ON
OUTPUT
LOGIC
OUTPUT
GROUND
SUPPLY
Dwg. FH-015-2
1
2
4
+
GAIN
OFFSET
MAGNET
Copyright 1998, 2002 Allegro MicroSystems, Inc.
ATS632LSA
HALL-EFFECT
GEAR-TOOTH SENSOR
www.allegromicro.com
3
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Supply Voltage
V
CC
Operating, T
J
< 165
C
4.5
24
V
Under-Voltage Lockout
V
CC(UV)
I
OUT
= 20 mA, V
CC
= 0
5 V
4.0
V
Low Output Voltage
V
OUT(L)
I
OUT
= 20 mA, Output ON
0.2
0.4
V
Output Current Limit
I
OUTM
V
OUT
= 12 V
25
45
55
mA
Output Leakage Current
I
OFF
V
OUT
= 24 V, Output OFF
0.2
5.0
A
Supply Current
I
CC
Output OFF, Target Speed = 0 RPM
9.0
15
mA
Calibration Count
n
cal
Output falling mechanical edges
16
16
16
Pulses
after power on for startup calibration
to be complete
Calibration Update
n
up
Output falling mechanical edges
64
64
64
Pulses
for the threshold calibration to be
complete
Power-On Time
t
po
V
CC
> 4.5 V
80
500
s
Output Rise Time
t
r
R
L
= 500
, C
L
= 10 pF
0.2
5.0
s
Output Fall Time
t
f
R
L
= 500
, C
L
= 10 pF
0.2
5.0
s
ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless
otherwise specified).
NOTE: Typical data is at V
CC
= 12 V and T
A
= +25
C and is for design information only.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
ATS632LSA
HALL-EFFECT
GEAR-TOOTH SENSOR
4
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Operating Air Gap Range
AG
Operating,
0.3
2.5
mm
Target Speed > 20 RPM
Output Polarity
Operating, Over Tooth
Low
Low
Low
Operating, Over Valley
High
High
High
Timing Accuracy
t
Target Speed < 3500 RPM,
0.25
0.50
0.3 mm
AG
2.0 mm
OPERATION over operating voltage and temperature range with reference target (unless oth-
erwise specified).
Limits
Characteristic
Symbol
Description
Min.
Typ.
Max.
Units
Valley Depth
h
t
5.0
mm
Valley Width
(P
C
- T)
5.0
mm
Tooth Width
T
5.0
mm
Thickness
F
5.0
mm
Eccentricity
Timing accuracy may change
0.25
mm
TARGET DESIGN CRITERIA
Diameter
Thickness
Tooth Width
Valley Width
Valley Depth
Type
(D
o
)
(F)
(T)
(P
C
- T)
(h
t
)
Reference Target
84 mm
16 mm
9 mm
13 mm
5 mm
Characterization Target #1
84 mm
16 mm
1 tooth, 180
5 mm
Characterization Target #2
35 mm
7 mm
1 tooth, 180
6 mm
TARGET DIMENSIONS
NOTE: Timing accuracy data is taken by recalibrating the unit at each air gap.
ATS632LSA
HALL-EFFECT
GEAR-TOOTH SENSOR
www.allegromicro.com
5
continued next page...
3.0
0
0.5
1.5
2.25
AIR GAP IN MILLIMETERS
RELATIVE TIMING ACCURACY IN DEGREES
Dwg. GH-063
1.0
2.0
2.0
1.0
-2.0
-3.0
-1.0
0.75
1.25
1.75
RISING EDGE
-40
C
+25
C
+150
C
TARGET #1
3.0
0
0.5
1.5
2.25
AIR GAP IN MILLIMETERS
Dwg. GH-063-1
1.0
2.0
2.0
1.0
-2.0
-3.0
-1.0
0.75
1.25
1.75
FALLING EDGE
-40
C
+25
C
+150
C
TARGET #1
RELATIVE TIMING ACCURACY IN DEGREES
3.0
0
0.5
1.5
2.25
AIR GAP IN MILLIMETERS
Dwg. GH-063-2
1.0
2.0
2.0
1.0
-2.0
-3.0
-1.0
0.75
1.25
1.75
RISING EDGE
-40
C
+25
C
+150
C
TARGET #2
RELATIVE TIMING ACCURACY IN DEGREES
3.0
0
0.5
1.5
2.25
AIR GAP IN MILLIMETERS
Dwg. GH-063-3
1.0
2.0
2.0
1.0
-2.0
-3.0
-1.0
0.75
1.25
1.75
FALLING EDGE
-40
C
+25
C
+150
C
TARGET #2
RELATIVE TIMING ACCURACY IN DEGREES
TYPICAL OPERATING CHARACTERISTICS
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