Allegro ATS612JSB Datasheet

ATS612JSB

DYNAMIC, SELF-CALIBRATING, PEAK-DETECTING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR

ATS612JSB

Data Sheet

27627.109

PRELIMINARY INFORMATION

(subject to change without notice)

November 20, 1998

1

2

3

4

Pin 1 = Supply
Pin 2 = Output
Pin 3 = Capacitor
Pin 4 = Ground

Dwg. AH-006

DYNAMIC, SELF-CALIBRATING,

PEAK-DETECTING, DIFFERENTIAL

HALL-EFFECT GEAR-TOOTH SENSOR

The ATS612JSB dynamically-coupled gear tooth sensor is a peak
detecting device that uses gain control to provide extremely accurate
gear edge detection down to low operating speeds. Each sensor
subassembly consists of a high-temperature plastic shell that holds
together a samarium-cobalt magnet, a pole piece, and a dynamically­coupled differential open-collector Hall 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
Hall-effect based. The sensor incorporates a dual-element Hall IC that
switches in response to differential magnetic signals created by ferrous
targets. The sophisticated processing circuitry contains a self-calibrat­ing 5-bit A/D converter that normalizes the internal gain of the device to
minimize the effect of air gap variations. The patented peak-detecting
filter circuit eliminates magnet and system offsets and has the ability to
discriminate relatively fast changes such as those caused by tilt, gear
wobble, and eccentricities yet provides stable operation to extremely
low RPMs.

ABSOLUTE MAXIMUM RATINGS

over operating temperature range

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

Reverse Supply Voltage, V
Output OFF Voltage, V
Continuous Output Current,

............................ Internally Limited

I

OUT

Reverse Output Current, I
Package Power Dissipation,

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

P

D

Operating Temperature Range,

................................. -40°C to +115°C*

T

A

Storage Temperature, TS.................. +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.

OUT

.............. -16 V

RCC

....................... 24 V

............ 50 mA

ROUT

These sensor systems are ideal for use in gathering speed, posi­tion, and timing information using gear-tooth-based configurations. The
ATS612JSB is particularly suited to those applications that require
extremely accurate duty cycle control or accurate edge detection similar
to crank shaft applications. The lower vibration sensitivity also makes
this device extremely useful for transmission speed sensing.

ATS612JSB: Large- or small-tooth gear-position sensing —
crank angle, transmission speed, cam angle.

continued next page…

Always order by complete part number: ATS612JSB .

ATS612JSB

DYNAMIC, SELF-CALIBRATING, PEAK-DETECTING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR

FEATURES AND BENEFITS

■ Fully Optimized Differential Digital Gear-Tooth Sensor

■ Single-Chip Sensing IC for High Reliability

■ Digital Output Representing Target Profile

■ Extremely Low Timing Accuracy Drift with Temperature

■ Large Operating Air Gaps

■ Small Mechanical Size

■ Optimized Magnetic Circuit

■ Patented Peak-Detecting Filter:

80 µs Typical Power-On Time
<10 RPM Operation (single-tooth target)
Correct First-Edge Detection
Uses Small Value Ceramic Capacitors

■ Under-Voltage Lockout

■ Wide Operating Voltage Range

■ Defined Power-On State

1000

800

R

θJA

600

400

200

0

ALLOWABLE PACKAGE POWER DISSIPATION IN mW

40 80 120

60 100 140 18020

AMBIENT TEMPERATURE IN °C

= 150°C/W

160

Dwg. GH-065-3

1

REG

MAGNET

Dwg. FH-014-1

SUPPLY

X

X

E1

E2

FUNCTIONAL BLOCK DIAGRAM

UVLO

GAIN

+
–

REFERENCE

POWER-ON

LOGIC

TRACK &

GENERATOR

HOLD

3

CAPACITOR

+
–

OUTPUT

2

CURRENT

LIMIT

GROUND

4

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

W
Copyright © 1998, Allegro MicroSystems, Inc.

ATS612JSB

DYNAMIC, SELF-CALIBRATING, PEAK-DETECTING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR

ELECTRICAL CHARACTERISTICS over operating voltage and temperature range,
C3 = 0.1

Characteristic Symbol Test Conditions Min. Typ. Max. Units

µF to 0.47 µF.

Limits

Supply Voltage V
Power-On State POS VCC = 0 → 5 V HIGH HIGH HIGH –
Under-Voltage Lockout V
Under-Voltage Hysteresis V
Low Output Voltage V
Output Current Limit I
Output Leakage Current I
Supply Current I

Power-On Delay t
Output Rise Time t

Output Fall Time t

NOTE: Typical data is at VCC = 8 V and TA = +25°C and is for design information only.

CC

CC(UV)
CC(hys)

OUT(SAT)

OUTM

OFF

CC

on

r

f

Operating, TJ < 165°C 3.6 – 24 V

I

= 20 mA, VCC = 0 → 5 V 2.5 – 3.6 V

OUT

Lockout (V
I

OUT

V

OUT

V

OUT

Output OFF 6.0 8.2 12 mA
Output ON 8.0 10 14 mA

VCC > 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

CC(UV)

= 20 mA – 190 400 mV

= 12 V 25 45 55 mA
= 24 V – 0.2 15 µA

) – Shutdown – 0.2 – V

ATS612JSB

DYNAMIC, SELF-CALIBRATING, PEAK-DETECTING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR

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

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Air Gap Range AG Operating, 0.4 – 2.5 mm

Target Speed > 20 RPM

Calibration Cycle n

cal

Output edges before which 1 1 1 Edge
calibration is completed*

Calibration Mode n

dis

Output falling edges for startup 64 64 64 Edges

Disable calibration to be complete
Timing Accuracy t

θ

Target Speed = 1000 RPM, – ±0.5 ±0.75 °

0.4 mm ≤ AG ≤ 2 mm

* Non-uniform magnetic profiles may require additional output pulses before calibration is completed.

REFERENCE TARGET

3 mm

t

h = 5 mm

TARGET

F (THICKNESS) ≥ 3 mm

D = 115 mm

o

T = 3 mm

E1 E2
SENSOR

POLE PIECE

SOUTH

PERMANENT

MAGNET

NORTH

1 2 3 4

AIR GAP

SIGNATURE

TOOTH (1)

Dwg. MH-016-2 mm

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

ATS612JSB

DYNAMIC, SELF-CALIBRATING, PEAK-DETECTING,
DIFFERENTIAL HALL-EFFECT GEAR-TOOTH SENSOR

TYPICAL ELECTRICAL CHARACTERISTICS

14

12

11

10

9.0

8.0

7.0

SUPPLY CURRENT IN mA

6.0

4.0

-40

0 40 80 120

AMBIENT TEMPERATURE IN °C

OUTPUT ON

OUTPUT OFF

275

V = 8 V

CC

160

Dwg. GH-014-2

200

13

12

11

10

9.0

8.0

7.0

SUPPLY CURRENT IN mA

6.0

5.0

OUTPUT ON

OUTPUT OFF

T = 25°C

A

2.0 6.0 10 14 18

SUPPLY VOLTAGE IN VOLTS

Dwg. GH-058-1

250

225

200

175

I = 20 mA

OUT

OUTPUT SATURATION VOLTAGE IN mV

150

-40

0 40 80 120

AMBIENT TEMPERATURE IN °C

160

200

Dwg. GH-013-2