Allegro ATS632LSA Datasheet

ATS632LSA

HALL-EFFECT
GEAR-TOOTH SENSOR
SUBASSEMBLY

NON-ORIENTED, HALL-EFFECT GEAR-TOOTH SENSOR

1

2

3

4

Pin 1 = Supply
Pin 2 = Output
Pin 3 = Test Point
Pin 4 = Ground

PRELIMINARY INFORMATION

(subject to change without notice)

December 2, 1998

Dwg. AH-006-2

ATS632LSA

ZERO-SPEED, SELF-CALIBRATING,

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 subassembly
consists of a high-temperature plastic shell that holds together a
compound samarium-cobalt magnet and a single-element self-calibrat­ing Hall-effect IC that has been optimized to the magnetic circuit. This
small package, with its non-oriented operation, can be easily as­sembled on a PC board for complete protection and used in conjunc­tion with a number of gear configurations.

The gear sensing technology used for this sensor subassembly 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 minimized by using active offset cancellation circuitry. The digital
algorithm provides zero-speed detection capabilities without the
associated running jitter inherent in classical digital solutions.

Data Sheet

27627.125

ABSOLUTE MAXIMUM RATINGS

Supply Voltage, VCC.........................24 V*

Reverse Supply Voltage, V
Output OFF Voltage, V
Output Current, I
Reverse Output Current, I
Package Power Dissipation,

.................................... See Graph

P

D

Operating Temperature Range,

............................ -40°C to +150°C

T

A

Storage Temperature, TS............ +170°C

* Operation at increased supply voltages with
external circuitry is described in Applications
Information.

OUT

.. Internally Limited

OUT

........ -24 V

RCC

................. 25 V

........ 50 mA

OUT

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.

continued next page…

Always order by complete part number, e.g., ATS632LSA .

ATS632LSA

ALLOWABLE PACKAGE POWER DISSIPATION IN mW

HALL-EFFECT
GEAR-TOOTH SENSOR
SUBASSEMBLY

FEATURES AND BENEFITS

■ Non-Oriented Installation

■ Fully Optimized Gear-Tooth Sensors

■ Zero-Speed Digital Output Representing Target

Profile

■ Large Operating Air Gaps

■ Extremely Low Timing Accuracy Drift with Tempera-

ture

■ Correct First-Edge Detection

■ Self-Calibrating Circuitry

with Integrated Offset Cancellation
6-bit A/D Converters to Capture Peaks
Thresholds Proportional to Peak-to-Peak Signals

■ Optimized Magnetic Circuit

■ Single-Chip Sensing IC for High Reliability

1000

800

600

400

200

RθJA = 147°C/W

0

40 80 120

60 100 140 18020

AMBIENT TEMPERATURE IN °C

160

Dwg. GH-065-1

MAGNET

X

FUNCTIONAL BLOCK DIAGRAM

SUPPLY

1

POWER ON

REG

TEST

3

POINT

GAIN

–

+

OFFSET

REFERENCE

GENERATOR

THRESHOLD

PEAK

LOGIC

OUTPUT

POSITIVE PEAK
TRACK & HOLD

NEGATIVE PEAK

TRACK & HOLD

CURRENT

LIMIT

2

OUTPUT

4

GROUND

Dwg. FH-015-2

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]

W
Copyright © 1998, Allegro MicroSystems, Inc.

ATS632LSA

HALL-EFFECT
GEAR-TOOTH SENSOR
SUBASSEMBLY

ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless
otherwise specified).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Supply Voltage V
Under-Voltage Lockout V
Low Output Voltage V
Output Current Limit I
Output Leakage Current I
Supply Current I
Calibration Count n

CC

CC(UV)

OUT(L)

OUTM

OFF

CC

cal

Operating, TJ < 165°C 4.5 – 24 V
I

= 20 mA, VCC = 0 → 5 V – 4.0 – V

OUT

I

= 20 mA, Output ON – 0.2 0.4 V

OUT

V

= 12 V 25 45 55 mA

OUT

V

= 24 V, Output OFF – 0.2 5.0 µA

OUT

Output OFF, Target Speed = 0 RPM – 9.0 15 mA
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
Output Rise Time t
Output Fall Time t

NOTE: Typical data is at VCC = 12 V and TA = +25°C and is for design information only.

po

r

f

VCC > 4.5 V – 80 500 µs

RL = 500 Ω, CL = 10 pF – 0.2 5.0 µs

RL = 500 Ω, CL = 10 pF – 0.2 5.0 µs

ATS632LSA

HALL-EFFECT
GEAR-TOOTH SENSOR
SUBASSEMBLY

OPERATION over operating voltage and temperature range with reference target (unless oth­erwise specified).

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

θ

Target Speed < 3500 RPM, – ±0.25 ±0.50 °

0.3 mm ≤ AG ≤ 2.0 mm

TARGET DESIGN CRITERIA

Limits

Characteristic Symbol Description Min. Typ. Max. Units

Valley Depth h
Valley Width (P
Tooth Width T – 5.0 – mm
Thickness F – 5.0 – mm
Eccentricity – Timing accuracy may change ––±0.25 mm

t

- T) – 5.0 – mm

C

– 5.0 – mm

TARGET DIMENSIONS

Diameter Thickness Tooth Width Valley Width Valley Depth

Type (D

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

NOTE: Timing accuracy data is taken by recalibrating the unit at each air gap.

) (F) (T) (PC - T) (ht)

o

115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]