Allegro ATS640JCB Datasheet
Data Sheet
27627.114
continued next page…
TRUE ZERO-SPEED, SELF-CALIBRATING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR
FOR TWO-WIRE APPLICATIONS
The ATS640JSB Hall-effect gear-tooth sensor is a peak detecting device
that uses internal gain control to provide extremely stable duty cycles down to
zero speed. Each sensor subassembly consists of a high-temperature plastic
shell that holds together a samarium-cobalt magnet, a pole piece, and a true
zero-speed BiCMOS differential Hall-effect gear-tooth sensor 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 gear-sensing technology used for this sensor subassembly is Halleffect based. The sensor incorporates a dual-element Hall IC that switches in
response to differential magnetic signals created by a ferrous target. The
sophisticated self-calibrating digital-processing circuitry normalizes the
internal gain of the device to minimize the effect of air gap variations. and to
reduce vibration sensitivity. The circuit eliminates magnet and system offsets
such as those caused by tilt yet 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 timing
information using gear-tooth-based configurations. The ATS640JSB is
particularly suited to those applications that require extremely accurate duty
cycle control or accurate edge detection. The lower vibration sensitivity also
makes this device extremely useful for transmission speed sensing.
Always order by complete part number: ATS640JSB .
Supply Voltage, VCC.......................... 26.5 V*
Reverse Supply Voltage, V
RCC
.............. -24 V
Output OFF Voltage, V
OUT
................... 26.5 V
Reverse Output Current, I
ROUT
............ 50 mA
Package Power Dissipation,
P
D
.......................................... See Graph
Operating Temperature Range,
T
A
................................ -40°C to +115°C*
Storage Temperature, T
S
.................. +170°C
* Operation at increased supply voltages with
external circuitry is described in Applications
Information. Devices for operation at increased
temperatures are available on special order.
ABSOLUTE MAXIMUM RATINGS
at TA = 25°C
Dwg. AH-006-3
A
1
2
3
4
Pin 1 = Supply
Pin 2 = Current Output
Pin 3 = No Connection
Pin 4 = Ground
ATS640JSB
PRELIMINARY INFORMATION
(subject to change without notice)
October 20, 2000
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
ATS640JSB
TRUE ZERO-SPEED,
TWO-WIRE
GEAR-TOOTH SENSOR
FEATURES AND BENEFITS
■ Internal Current Regulator for 2-Wire Operation
■ True Zero-Speed Operation
■ Self Calibrating
■ Extremely Stable Duty Cycle with Temperature
■ Fully Optimized Differential Digital Gear-Tooth Sensor
■ Large Operating Air Gaps
■ Air-Gap Independent Switch Points
■ High Vibration Immunity
■ Single-Chip Sensing IC for High Reliability
■ Digital Output Representing Target Profile
■ Small Mechanical Size
■ Optimized Magnetic Circuit
■ <200 µs Typical Power-On Time
■ AGC and Reference-Adjust Circuit
■ Under-Voltage Lockout
■ Wide Operating Voltage Range
■ Defined Power-On State
Copyright © 2000, Allegro MicroSystems, Inc.
FUNCTIONAL BLOCK DIAGRAM
TYPICAL APPLICATION
NEGATIVE PEAK
ADC - DAC
TRACK & HOLD
POSITIVE PEAK
ADC - DAC
TRACK & HOLD
CURRENT
OUTPUT
SUPPLY
1 2
INTERNAL
CONNECTION
3
Dwg. FH-019
GROUND
REG
4
POWER-ON
LOGIC
E2
UVLO
MAGNET
E1
X
X
OUTPUT
LOGIC
REFERENCE
GENERATOR
–
+
GAIN
–
+
–
+
100 Ω
Dwg. EH-011-1B
0.1 µF
3
1
2
4
X
X
+
-
Vcc
NC
SUPPLY
Icc + Io
1 V
–
+
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