ALLEGRO ATS643LSH User Manual

查询ATS643LSH供应商
Package SH, 4-pin SIP
1
2
3
4
1. VCC
2. No connection (float or tie to VCC)
3. Test pin (float or tie to GND)
4. GND
ATS643LSH
Self-Calibrating, Zero-Speed Differential
Gear Tooth Sensor with Continuous Update
The ATS643 is an optimized combination of integrated circuit and magnet that provides a manufacturer-friendly solution for true zero-speed digital gear-tooth sensing in two-wire applications. The device consists of a single-shot molded plastic package that includes a samarium cobalt magnet, a pole piece, and a Hall-effect IC that has been optimized to the magnetic circuit and the automotive environment. 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 with signal processing circuitry that switches in response to differential magnetic signals created by rotating ferrous targets. The device contains a sophisticated compen­sating circuit to eliminate magnet and system offsets immediately at power-on. Digital tracking of the analog signal is used to achieve true zero-speed operation, while also setting the device switchpoints. The resulting switchpoints are air gap independent, greatly improving output and duty cycle accuracy. The device also uses a continuous update algorithm to fine-tune the switchpoints while in running mode, maintaining the device specifications even through large changes in air gap or temperature.
The regulated current output is configured for two-wire operation, offering inher­ent diagnostic information. This device is ideal for obtaining speed and duty cycle information in gear-tooth based applications such as transmission speed sensing.
AB SO LUTE MAX I MUM RAT INGS
Supply Voltage, VCC..................See Power Derating
Reverse-Supply Voltage, V Operating Temperature Ambient, T Maximum Junction, T Storage Temperature, T
ATS643-DS, Rev. 1
................................ –40ºC to 150ºC
A
........................–18 V
RCC
........................165ºC
J(max)
.................. –65ºC to 170ºC
S
Features and Benefits
• Fully-optimized differential digital gear tooth sensor
• Single chip-IC for high reliability
• Internal current regulator for 2-wire operation
• Small mechanical size (8 mm diameter x 5.5 mm depth)
• Switchpoints air gap independent
• Digital output representing gear profile
Use the following complete part numbers when ordering:
Part Number Package ICC Typical
ATS643LSH-I1 4-pin plastic SIP 6.0 Low to 14.0 High mA
ATS643LSH-I2 4-pin plastic SIP 7.0 Low to 14.0 High mA
• Precise duty cycle accuracy through­out temperature range
• Large operating air gaps
• <2 ms power-on time
• AGC and reference adjust circuit
• True zero-speed operation
• Undervoltage lockout
• Wide operating voltage range
• Defined power-on state
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
ATS643LSH
Self-Calibrating, Zero-Speed Differential GTS with Continuous Update
Functional Block Diagram
VCC (Pin 1)
PDAC
NDAC
Hall AMP
Offset Adjust
ThresholdP
Reference Generator and
Updates
ThresholdN
AGC
Internal
Regulator
Threshold
Logic
GND (Pin 4)
ATS643-DS, Rev. 1
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
2
ATS643LSH
Self-Calibrating, Zero-Speed Differential GTS with Continuous Update
OPERATING CHARACTERISTICS using reference target 60-0, TA and VCC within specification, unless otherwise noted
Characteristic Symbol Test Conditions Min. Typ. Max. Units
ELECTRICAL CHARACTERISTICS
Supply Voltage V
Undervoltage Lockout V
CC(UV) VCC
Supply Zener Clamp Voltage V
I
CC(Low)
Supply Current
I
CC(High)
I
Supply Current Ratio
CC(High)
I
CC(Low)
POWER-ON CHARACTERISTICS
Power-On State I
Power-On Time
1
CC(PO)
OUTPUT STAGE
Output Slew Rate
2
dI/dt R
Output State V
CC
t
on
OUT
Operating; TJ < 165 °C 4.0 24 V
0 5 V 3.5 4.0 V
ICC = 19 mA for ATS643-I1, and 19.8 mA for
Z
ATS643-I2; TA = 25°C
28 V
ATS643-I1 4.0 6 8.0 mA
ATS643-I2 5.9 7 8.4 mA
ATS643-I1 12.0 14.0 16.0 mA
ATS643-I2 11.8 14.0 16.8 mA
/
Ratio of high current to low current 1.85 3.05
t < ton; dI/dt < 5 µs High mA
Target gear speed < 100 rpm 1 2 ms
= 100 , C
LOAD
R
on high side (VCC pin); ICC = I
SENSE
R
on low side (GND pin); ICC = I
SENSE
= 10 pF 7 mA/µs
LOAD
CC(High)
CC(High)
Low mV
High mV
Continued on the next page.
ATS643-DS, Rev. 1
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
3
ATS643LSH
Self-Calibrating, Zero-Speed Differential GTS with Continuous Update
OPERATING CHARACTERISTICS (continued) using reference target 60-0, TA and VCC within specification, unless otherwise noted
Characteristic Symbol Test Conditions Min. Typ. Max. Units
SWITCHPOINT CHARACTERISTICS
Rotation Speed S
ROT
Reference Target 60-0 0 12,000 rpm
Bandwidth BW Equivalent to f – 3dB 25 40 kHz
Operate Point B
Release Point B
CALIBRATION
3
Initial Calibration Period C
AGC Calibration Disable C
Start Mode Hysteresis PO
OP
RP
I
f
HYS
% of peak to peak referenced from PDAC to NDAC, AG < AG
MAX
% of peak to peak referenced from PDAC to NDAC, AG < AG
MAX
Quantity of rising output (current) edges required for accurate edge detection
Quantity of rising output (current) edges used for calibrating AGC
–65– %
–35– %
3 Edge
3 Edge
175 mV
DAC CHARACTERISTICS
Dynamic Offset Cancellation ±60 G
Tracking Data Resolution
Quantity of bits available for PDAC/NDAC tracking of both positive and negative signal peaks
–9–Bit
FUNCTIONAL CHARACTERISTICS
Air Gap Range
Maximum Operable Air Gap AG
4
AG DC within specification 0.5 2.5 mm
(opmax)
Output switching (no missed edges); DC not guaranteed
2.75 mm
Duty Cycle Variation DC Wobble < 0.5 mm, AG within specification ±10 %
Input Signal Range Sig DC within specification 40 1400 G
Minimum Operable Input Signal Sig
1
Power-On Time includes the time required to complete the internal automatic offset adjust. The DACs are then ready for peak acquisition.
2
dI is the difference between 10% of I
of the bypass capacitor, if one is used.
3
Continuous Update (calibration) functions continuously during Running mode operation.
4
AG is dependent on the available magnetic field. The available field is dependent on target geometry and material, and should be independently
characterized. The field available from the reference target is given in the reference target parameter section of the datasheet.
ATS643-DS, Rev. 1
CC(Low)
(opmin)
and 90% of I
Output switching (no missed edges); DC not guaranteed
, and dt is time period between those two points. Note: dI/dt is dependent upon the value
CC(High)
30 G
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
4
ATS643LSH
Reference Gear Magnetic P rofile Two Tooth-to-Valley Transitions
-700
-600
-500
-400
-300
-200
-100
0
100
200
300
400
500
600
700
0123456789101112
AG (mm)
Self-Calibrating, Zero-Speed Differential GTS with Continuous Update
REFERENCE TARGET, 60-0 (60 Tooth Target)
Characteristics Symbol Test Conditions Typ. Units Symbol Key
Outside Diameter D
Face Width F
Circular Tooth Length t
Circular Valley Length t
Tooth Whole Depth h
Outside diameter of target
o
Breadth of tooth, with respect to sensor
Length of tooth, with respect to sensor; measured at D
Length of valley, with respect
v
to sensor; measured at D
t
120 mm
6mm
3mm
o
3mm
o
3mm
Material Low Carbon Steel
Peak-to-Peak Differential B* (G)
Reference Gear Magnetic Gradient Amplitude
1800
1600
1400
1200
1000
800
600
400
200
0
0.5 1 1.5 2 2.5
with Reference to Air Gap
Branded Face
of Sensor
Reference Target
60-0
Differential B* (G)
Gear Rotation (°)
*Differential B corresponds to the calculated difference in the magnetic fi eld as
sensed simultaneously at the two Hall elements in the device (B
= BE1 – BE2).
DIFF
ATS643-DS, Rev. 1
2.00 mm AG
0.50 mm AG
AG (mm)
0.50
0.75
1.00
1.25
1.50
1.75
2.00
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
5
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