ATS622LSB
Data Sheet
27627.105
TRUE ZERO-SPEED
HALL-EFFECT GEAR-TOOTH SENSOR
The ATS622LSB 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. The sensor module
consists of a plastic shell that holds together a samarium-cobalt magnet,
a pole piece, and a Hall-effect sensor 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 the ferrous gear teeth. The circuitry
contains a sophisticated digital circuit to eliminate magnet and system
offsets and to achieve true zero-speed operation (manufactured under
U.S. Pat. 5,917,320). A-to-D and D-to-A converters are used to adjust
the device gain at power on and to allow air-gap independent switching,
which greatly reduces vibration sensitivity of the device.
This sensor system is ideal for obtaining transmission and crank
information using gear-tooth-based configurations.
FEATURES AND BENEFITS
s Tight timing accuracy over temperature
s True zero-speed operation
s Air-gap independent switch points
s High vibration immunity
s Extremely precise duty cycle signal with temperature
s Large operating air gaps
s Defined power-on state
s Wide operating voltage range
s Digital output representing gear profile
s Single-chip sensing IC for high reliability
s Small mechanical size (9 mm diameter x 7 mm length)
s Optimized magnetic circuit
s <200
s power-on time
s AGC and reference-adjust circuit
s Under-voltage lockout
Always order by complete part number: ATS622LSB .
Dwg. AH-006-6
1
2
3
4
Pin 1 = Supply
Pin 2 = Output
Pin 3 = No Connection
Pin 4 = Ground
ABSOLUTE MAXIMUM RATINGS
at T
A
= 25
C
Supply Voltage, V
CC
........................ 26.5 V*
Reverse Supply Voltage, V
RCC
............ -24 V
Continuous Output Current, I
OUT
....... 20 mA
Reverse Output Current, I
ROUT
.......... 50 mA
Package Power Dissipation,
P
D
.......................................... See Graph
Operating Temperature Range,
T
A
............................. -40
C to +150
C*
Junction Temperature,
(continuous), T
J
.......................... +165
C
(100 s), T
JM
................................ +180
C
Storage Temperature, T
S
................... +170
C
* Operation at increased supply voltages with
external circuitry is described in Applications
Information. Devices for operation at in-
creased temperatures are available on special
order.
Some restrictions may apply to certain types of sales.
Contact factory for details.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
ATS622LSB
TRUE ZERO-SPEED,
GEAR-TOOTH SENSOR
2
Copyright 2002, 2003 Allegro MicroSystems, Inc.
FUNCTIONAL BLOCK DIAGRAM
600
400
200
40
80
120
160
0
AMBIENT TEMPERATURE IN
C
ALLOWABLE PACKAGE POWER DISSIPATION IN mW
Dwg. GH-065-6
60
100
140
180
20
800
1000
R
JA
= 147
C/W
CONTINUOUS
100 HOURS MAX.
SUPPLY
1
REG
UVLO
POWER-ON
LOGIC
+
REF
NO (INTERNAL)
CONNECTION
3
E2
MAGNET
E1
X
X
+
Dwg. FH-019-3
GROUND
4
OUTPUT
2
OUTPUT
LOGIC
+
+
POSITIVE PEAK
DIGITAL PROC.
NEGATIVE PEAK
DIGITAL PROC.
32 V
THRESHOLD
COMPARATORS
REFERENCE
GENERATOR
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
ATS622LSB
TRUE ZERO-SPEED,
GEAR-TOOTH SENSOR
4
OPERATION over operating voltage and temperature range with reference target (unless oth-
erwise noted)
Limits
Characteristic
Symbol
Description
Min.
Typ.
Max.
Units
Air Gap Range
AG
Operating, target speed > 20 RPM
0.5
2.5
mm
Calibration Cycle
n
cal
Output edges before which
1
1
1
Edge
calibration is completed*
Calibration Update
n
r
Output falling edges for startup
64
64
64
Edges
calibration to be complete
Minimum Speed
n
min
0
r/s
Maximum Speed
n
max
60 teeth per second = 1 r/s
133
r/s
Timing Accuracy
t
Target speed = 1000 rpm,
0.2
0.5
0.5 mm < AG < 2.5 mm
* Non-uniform magnetic profiles may require additional output pulses before calibration is completed.
REFERENCE GEAR DIMENSIONS (60-0)
Limits
Characteristic
Symbol
Description
Min.
Typ.
Max.
Units
Diameter
D
O
120
mm
Tooth Width
T
3.0
mm
Valley Width
(p
C
T)
3.0
mm
Valley Depth
h
t
3.0
mm
Thickness
F
3.0
mm
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