ALLEGRO ATS645LSH User Manual

Download

True Zero Speed

a Hall effect IC that has been optimized to the magnetic circuit.

查询ATS645LSH供应商

ATS645LSH

Preliminary – Subject to Change

PRELIMINARY DATASHEET

(subject to change without notice)

Pin 1: Supply Pin 2: No connection Pin 3: Test pin Pin 4: Ground

Miniature Gear Tooth Sensor

The ATS645LSH 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 in two-wire applications. The sensor consists of a single-shot molded plastic package that includes a samarium cobalt magnet, a pole piece, and

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 ferrous gear teeth. The circuitry contains a sophisticated digital circuit to eliminate magnet and system offsets and to achieve true zero speed operation (ref U.S. Patent 5,917,320). A-D and D-A converters are used to adjust the device gain at power up and to allow air gap independent switching.

The regulated current output is configured for two wire applications and the sensor is ideally suited for obtaining speed and duty cycle in ABS and transmission application gear-tooth-based configurations.

ABSOLUTE MAXIMUM RATINGS

Supply Voltage,

VCC . . . . . . . . . . . . . . . . . . . . . . . . . 26.5 V*

Reverse Supply Voltage,

VR . . . . . . . . . . . . . . . . . . . . . . . . . . . . –18 V

Operating Temperature Range,

TA . . . . . . . . . . . . . . . . . –40 °C to 150 °C*

Storage Temperature,

TS . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 °C

Package Power Rating,

ϑJA . . . . . . . . . . . . . . . . . . . . . . . . 126 °C/W

Maximum Junction Temperature, T

* Operation at increased supply voltages with external

circuitry is described in the Applications Information.

. . . . . . . . . . . . . . . . . . . . . 165 °C

Jmax

FEATURES

s Fully optimized differential digital gear tooth sensor s Single chip sensing IC for high reliability s Internal current regulator for 2 wire operation s Small mechanical size (8 mm dia x 5.5 mm length) s Air gap independent switch points s Digital output representing gear profile s Precise duty cycle signal with temperature s Large operating air gaps s Automatic Gain Control (AGC) s Automatic Offset Adjustment circuit s True zero speed operation s Under-voltage lockout s Wide operating voltage range s Defined power-on state

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

CHARACTERISTICS

Valid over operating temperature range and Supply Voltage within specification unless otherwise noted.

Limits

Characteristics Symbol Test Conditions

Min. Typ. Max. Units

ELECTRICAL CHARACTERISTICS

Supply Voltage VCC Operating, TJ < 165°C 4.0 24 V Under Voltage Lockout V

Supply Zener Clamp Voltage VZ IZT = 1 mA 28 32 - V

VCC 0 → 5 V - - <Vcc

CC(UV)

Min

Max Zener Pulse Current IZ t=20mS Pulse Mode - - 50 mA Supply Zener Resistance RZ - 50 - Ω

Supply Current ATS645LSH – I1

Supply Current ATS645LSH – I2

ICC

Low Current State: Icc

High Current State: Icc

Low Current State: Icc

ICC

High Current State: Icc

4.0 6 8.0 mA

Low

12.0 14.0 16.0 mA

High

5.9 7 8.4 mA

Low

11.8 14.0 16.8 mA

High

POWER-ON STATE CHARACTERISTICS

Power-On State SPO VCC 0 → 5 V - Icc

Power-On Time t

Gear speed < 100 rpm - 1 2 ms

- -

High

OUTPUT STAGE

Icc

Output Current Slew Rate IR

à Icc

High

RS = 100 Ω, CS = 10 pF, 10 to 90%

Low

, Icc

Low

à Icc

High

mA/µs

The zener is tested using a pulse method and is designed for transient protection, continuous operation may destroy the device.

Power On Time is the time required to complete internal offset adjust. It does not include automatic gain control, which requires

three tooth valley transitions to complete and is therefore RPM dependent.

Revision 1.2; MHN; 07.Aug.02

Page 2 of 12

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Operating Characteristics: Valid with Reference Target unless otherwise specified

Characteristics Symbol Test Conditions

Min. Typ. Max. Units

SWITCH POINT CHARACTERISTICS

Rotation Speed S

max

Using Reference Target over Operating Air Gap Range

Analog Signal Bandwidth f-3db -3dB Point 20 40 KHz

Operate Point Bop

Release Point Brp

Icc

High

à Icc

Low

Positive Peak referenced, AG < AG Icc

Low

à Icc

High

Negative Peak referenced, AG < AG

max

Calibration

Initial Calibration CI

Number of Rising Mechanical Edges for

Accurate Edge Detection

DAC Characteristics Allowable User Induced

Differential Offset

Output switching only; may not meet data sheet specifications

-60 60 G

Limits

0 8K RPM

- 100 150 mV

3 Edges

SWITCH POINT DETAIL

Bop

Input

Differential

Signal

Device Output

Current

Pin 3 Differential Signal (not magnetic signal)

Bop and Brp should be adjustable with metal mask changes, limits max air gap but improves vibration immunity.

Revision 1.2; MHN; 07.Aug.02

Page 3 of 12

Brp

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Operating Characteristics: Valid only if magnetic offset is within the Dynamic Offset Compensation DAC Range as specified above

Characteristics Symbol Test Conditions

Min. Typ. Max. Units

OPERATING CHARACTERISTICS: Using Reference Target and Valid Over Operating Temperature Range

Operational Air Gap Range Op

Switching Air Gap Range Op

MaxAG

Duty cycle within specification 0.5 2.75 mm

Output Switching: Duty cycle Not in Specification Wobble < 0.5mm

Duty Cycle Variation DC

Typical value at 1.5mm air gap

37 53 57 %

Valid over operating air gap range

Operating Signal Range Sig

Minimum Operating Signal

Sig

Duty cycle within Specification Wobble < 0.5mm Output Switching: Duty Cycle Not in

Min

Specification

30 - 1000 G 20 - - G

Limits

3 - - mm

Operating air gap is dependent on the available magnetic field. The available field is target geometry and materiel dependent and should be independently characterized. The field available from the reference target is given in the reference gear parameter section of the datasheet

In order to remain in specification the magnetic signal must be larger than the minimum value specified, this includes the effect of target wobble.

Duty cycle is not guaranteed to be in specification. Reference the Duty Cycle vs. Air Gap Over Temperature graph in the typical operating characteristics section of this document.

Revision 1.2; MHN; 07.Aug.02

Page 4 of 12

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Reference Gear Parameters

REFERENCE GEAR DIMENSIONS (60-0)

Diameter G

- 120 - mm Thickness Gt - 6 - mm Tooth Width Tw - 3 - mm Valley Width V

- 3 - mm Valley Depth Vd - 3 - mm Materiel Low Carbon Steel

300

0.94mm

250

1.19mm

1.44mm

1.69mm

200

1.94mm

2.19mm

150

2.44mm

2.69mm

2.94mm

100

3.19mm

3.44mm

3.69mm

-50

Flux Density (Gauss)

-100

-150

-200

-250

-300 244 246 248 250 252 254 256 258 260 262

Flux Density vs. Position

Reference Target

Position (º)

Target Description:

Tooth Width: 3.25mm Diameter: 120mm Valley Width: 3.10mm Tooth Thickness: 6mm Valley Depth: 3mm

Revision 1.2; MHN; 07.Aug.02

Page 5 of 12

500

450

400

350

300

250

P-P [Gauss]

200

150

100

0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75

Reference Target Peak to Peak vs. Air Gap

Air Gap [mm]

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Typical Operating Characteristics: Duty Cycle vs. Air Gap Over Temperature

Allegro MicroSystems, Inc. Standard Production 60-0 Target

Typical @ 25ºC Typical @ 150ºC Typical @ -40ºC

Duty Cycle (%)

0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25

Figure #1: Duty Cycle vs. Air Gap Over Tem perature with Reference Target and Orientation Given in Figure #2

Duty Cycle vs. Air Gap

ATS645LSH @ 1000RPM

Air Gap (mm)

ROTATION RIGHT is CW from pin 4 to pin 1

Figure #2: Sensor Orientation and Direction of Rotation of Reference Target for Duty Cycle Graph in Figure #1

Revision 1.2; MHN; 07.Aug.02

Page 6 of 12

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

SENSOR DESCRIPTION

Assembly Description:

The ATS645LSH true zero speed gear tooth sensor is a Hall IC/magnet configuration that is fully optimized to provide digital detection of gear tooth edges. This sensor is integrally molded into a plastic body that has been optimized for size, ease of assembly, and manufacturability. High operating temperature materials are used in all aspects of construction.

Sensing Technology: The gear tooth sensor sub-assembly contains a single-chip differential Hall effect sensor IC, a Samarium Cobalt magnet, and a flat ferrous pole piece. The Hall IC consists of 2 Hall elements spaced 1.5 mm apart that measure the magnetic gradient created by the passing of a ferrous object. The two elements measure the magnetic gradient and convert it to an analog voltage that is then processed to provide a digital output signal.

Revision 1.2; MHN; 07.Aug.02

Page 7 of 12

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Transient Performance per ISO 7637-1

at TA = 23 ±5°C

(Tested at Allegro test facility – for engineering reference only)

Performance Class at Test Level

Pulse No. Test

1 Inductive turn off (negative) - - - C 2 Inductive turn off (positive) - - - A 3a Capacitive/inductive coupling (neg) - - - A 3b Capacitive/inductive coupling (pos) - - - A 4 Reverse battery - - - A 5 Load dumb A C C E

6 Ignition coil disconnect - - C E 7 Field decay (negative) - - - C

UA = 13.5V for pulses 1, 2, 3a, 3b, 5, 6, 7 and 12V for pulse 4.

Test Circuit #1

PCB Ouline by Dashed Line

Icc

Pin #1

Pin #2 Pin #3

Pins #2 and #3 Floating

Power supply voltage transients, or device output short circuits, may be caused by faulty connectors, crimped wiring harnesses, or service errors. The prevent catastrophic failure, internal protection against over-voltage, reverse voltage, and output overloads have been incorporated to meet the automotive 12 volt system protection requirements of ISO DP7637/1. A series-blocking diode or current -limiting resistor is required in order to survive pulse number six.

645

Pin #4

Transient & EMC test circuit

0.01uF

ECU

100Ohm

EMC

A – All functions of a device perform as designed during and after the exposure.

B – All functions of a device perform as designed during exposure; however, one or more of them may go beyond the specified limit tolerance. All functions return automatically to within normal limits after exposure is removed. Memory must remain Class A.

C – One or more functions of the device do not perform as designed during exposure but return automatically to normal operation after exposure is removed.

D – One or more functions of the device do not perform as designed during exposure and do not return to normal operation until exposure is removed and the device is reset by simple “ operator” action.

E – One or more functions of the device do not perform as designed during and after the exposure and cannot be returned to proper operation without repairing or replacing the device.

Revision 1.2; MHN; 07.Aug.02

Page 8 of 12

I II III IV

Performance Class Definitions

(for transient performance and EMC performance)

Performance Class at Test Level

Frequency Band

Performance Class at Test Level

Frequency Band

Performance Class at Test Level

Frequency Band

Test severity level

I = 50 V/m

II = 100 V/m III = 150 V/m IV = 200 V/m

Test severity level

I = 25 mA

II = 50 mA

III = 75 mA

IV = 100 mA

Test severity level

I = 100 mW

II = 200 mW

III = 300 mW

IV = 400 mW

V = 500 mW

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

ELECTROMAGNETIC COMPATIBILITY (EMC) PERFORMANCE

at TA = 23 ±5°C

(Tested at Allegro test facility – for engineering reference only)

TEM Cell Performance per ISO 11452-3

(MHz) I II III IV

F1 (0.01 to 10)

F2 (0 to 30)

F3 (30 to 80)

F4 (80 to 200)

(MHz) I II III IV

F1 (1 to 10) F2 (10 to 30) F3 (30 to 80)

F4 (80 to 200)

F5 (200 to 400)

(MHz)

F1 (1 to 10) F2 (10 to 30) F3 (30 to 80)

F4 (80 to 200)

F5 (200 to 400)

– – – – – – – – – –

A B B

BCI per ISO 11452-4

– – – – – – – – – – – – – – –

Direct RF per ISO 11452-7

I II III IV V

A A A

A A A A A

Revision 1.2; MHN; 07.Aug.02

Page 9 of 12

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

MECHANICAL INFORMATION

Component Material Function Value

Sensor Package

Material

Leads Copper, 0.016” dia, 0.050” spacing

Lead Coating Solder, Tin / Lead 90/102

Temperature excursions of up to 225°C for 2 minutes or less are permitted.

Industry accepted soldering techniques are acceptable for this sub-assembly as long as the indicated maximum

temperatures for each component are not exceeded.

Thermoset Epoxy Max. Temperature 170°C1

DEVICE QUALIFICATION PROGRAM

Test Name Test Conditions Test Length # of Lots Sample / lot

High Temperature Operating Life

High Temperature Bake Temperature Humidity

Bias Autoclave AEC-Q100 #6 (JA102) 96 hrs 1 77

Temperature Cycling AEC-Q100 #7(JA104) 500 cycles 1 77

ESD

Early Life Failure Rate

AEC-Q100 #2 (JA108) Ta = 150°C, Tj = 165°C AEC-Q100 #3 (JA103) Ta = 170°C AEC-Q100 #5 (JA101) 85°C/85%RH

AEC-Q100 #20 (AEC-Q100002, AEC-Q100-003)

AEC-Q100 #25 (AEC-Q100-

008)

408 hrs 1 77 1000 hrs 1 77 1008 hrs 1 77

- 1 3/model/step

150°C/24 hrs 1 800

-65°C to +160°C, 30 sec. transition, 30 minute dwell Passes ±6kV all pin combinations: Human Body Model

Comments

Revision 1.2; MHN; 07.Aug.02

Page 10 of 12

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

Functional block diagram

ATS645LSH – Preliminary – Allegro Confidential

Vcc/Output

Auto Offset

Control

Track DAC

Hall AMP AGC

Offset DAC

AGC DAC

Peak Hold

Typical Application Circuit

INTERNAL

REGURATOR

Test signals

Neg

Test Pin

Revision 1.2; MHN; 07.Aug.02

Page 11 of 12

PCB Ouline by Dashed Line

Pin #1

Pin #2

Pin #3

645

Pin #4

Pins #2 and #3 Floating

0.01uF

Icc

ECU

100Ohm

Supply

ATS645LSH – Preliminary – Allegro Confidential

TRUE ZERO SPEED DIFFERENTIAL PEAK DETECTOR

SENSOR PACKAGE

LSH PACKAGE

REFERENCE DIMENSIONS ONLY

Revision 1.2; MHN; 07.Aug.02

Page 12 of 12

ALLEGRO ATS645LSH User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual