Data Sheet 27627.125 ATS632LSA ZERO-SPEED, SELF-CALIBRATING, NON-ORIENTED, HALL-EFFECT GEAR-TOOTH SENSOR 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 module 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. 1 2 3 4 Pin 1 = Supply Pin 2 = Output Pin 3 = Test Point Pin 4 = Ground Dwg. AH-006-2 PRELIMINARY INFORMATION T C U D N O L R P LSB The gear sensing technology used for this sensor 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. 2 D 7 E 6 S U T N yA I T b N d e O c a C l p S e I D R (subject to change without notice) August 28, 2002 ABSOLUTE MAXIMUM RATINGS 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. Supply Voltage, VCC ......................... 24 V* Reverse Supply Voltage, VRCC ........ -24 V Output OFF Voltage, VOUT ................. 25 V Output Current, IOUT .. Internally Limited Reverse Output Current, IOUT ........ 50 mA continued next page… Package Power Dissipation, PD .................................... See Graph Operating Temperature Range, TA ............................ -40°C to +150°C Storage Temperature, TS ............ +170°C * Operation at increased supply voltages with external circuitry is described in Applications Information. Always order by complete part number, e.g., ATS632LSA . ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR FEATURES AND BENEFITS ■ ■ ■ ■ ■ ■ ALLOWABLE PACKAGE POWER DISSIPATION IN mW ■ ■ ■ 1000 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 Temperature 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 800 RθJA = 147°C/W 600 400 200 0 20 40 60 100 140 80 120 AMBIENT TEMPERATURE IN ° C FUNCTIONAL BLOCK DIAGRAM 1 SUPPLY POWER ON REG 3 TEST POINT MAGNET – + OFFSET REFERENCE GENERATOR THRESHOLD PEAK OUTPUT LOGIC GAIN X 2 OUTPUT 4 GROUND CURRENT LIMIT POSITIVE PEAK TRACK & HOLD NEGATIVE PEAK TRACK & HOLD Dwg. FH-015-2 2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1998, 2002 Allegro MicroSystems, Inc. 160 180 Dwg. GH-065-1 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless otherwise specified). Limits Characteristic Supply Voltage Symbol VCC Test Conditions Operating, TJ < 165°C Min. Typ. Max. Units 4.5 – 24 V Under-Voltage Lockout VCC(UV) IOUT = 20 mA, VCC = 0 → 5 V – 4.0 – V Low Output Voltage VOUT(L) IOUT = 20 mA, Output ON – 0.2 0.4 V Output Current Limit IOUTM VOUT = 12 V 25 45 55 mA Output Leakage Current IOFF VOUT = 24 V, Output OFF – 0.2 5.0 µA Supply Current ICC Output OFF, Target Speed = 0 RPM – 9.0 15 mA Calibration Count ncal Output falling mechanical edges after power on for startup calibration to be complete 16 16 16 Pulses Calibration Update nup Output falling mechanical edges for the threshold calibration to be complete 64 64 64 Pulses Power-On Time tpo VCC > 4.5 V – 80 500 µs Output Rise Time tr RL = 500 Ω, CL = 10 pF – 0.2 5.0 µs Output Fall Time tf RL = 500 Ω, CL = 10 pF – 0.2 5.0 µs NOTE: Typical data is at VCC = 12 V and TA = +25°C and is for design information only. www.allegromicro.com 3 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR OPERATION over operating voltage and temperature range with reference target (unless otherwise specified). Limits Characteristic Operating Air Gap Range Output Polarity Timing Accuracy Symbol AG – tθ Test Conditions Min. Typ. Max. Units Operating, Target Speed > 20 RPM 0.3 – 2.5 mm Operating, Over Tooth Low Low Low – Operating, Over Valley High High High – – ±0.25 ±0.50 ° Target Speed < 3500 RPM, 0.3 mm ≤ AG ≤ 2.0 mm TARGET DESIGN CRITERIA Limits Characteristic Symbol Description Min. Typ. Max. Units Valley Depth ht – 5.0 – mm Valley Width (PC - T) – 5.0 – mm Tooth Width T – 5.0 – mm Thickness F – 5.0 – mm Eccentricity – – – ±0.25 mm Timing accuracy may change TARGET DIMENSIONS Diameter (Do) Thickness (F) Tooth Width (T) Valley Width (PC - T) Valley Depth (ht) 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 Type NOTE: Timing accuracy data is taken by recalibrating the unit at each air gap. 4 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR TYPICAL OPERATING CHARACTERISTICS 3.0 TARGET #1 TARGET #1 2.0 RELATIVE TIMING ACCURACY IN DEGREES RELATIVE TIMING ACCURACY IN DEGREES 3.0 -40°C +25°C +150°C 1.0 RISING EDGE 0 -1.0 -2.0 -3.0 1.0 0 FALLING EDGE -1.0 -2.0 -3.0 0.5 0.75 1.0 1.25 1.5 1.75 2.0 AIR GAP IN MILLIMETERS 2.25 0.5 0.75 1.0 1.25 1.5 1.75 Dwg. GH-063 2.25 2.0 AIR GAP IN MILLIMETERS Dwg. GH-063-1 3.0 3.0 TARGET #2 2.0 RELATIVE TIMING ACCURACY IN DEGREES TARGET #2 RELATIVE TIMING ACCURACY IN DEGREES -40°C +25°C +150°C 2.0 -40°C +25°C +150°C 1.0 0 RISING EDGE -1.0 -2.0 -40°C +25°C +150°C 2.0 1.0 0 FALLING EDGE -1.0 -2.0 -3.0 -3.0 0.5 0.75 1.0 1.25 1.5 AIR GAP IN MILLIMETERS 1.75 2.0 2.25 0.5 0.75 1.0 1.25 1.5 AIR GAP IN MILLIMETERS Dwg. GH-063-2 1.75 2.0 2.25 Dwg. GH-063-3 continued next page… www.allegromicro.com 5 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR TYPICAL OPERATING CHARACTERISTICS — Continued 51.0 51.0 TARGET #2 TARGET #1 50.0 49.5 49.0 50.0 49.5 49.0 48.5 48.5 48.0 48.0 0.5 0.75 1.0 1.25 1.5 1.75 2.0 0.5 2.25 1.25 1.5 1.75 2.0 2.25 Dwg. GH-008-4 Dwg. GH-008-3 +3 +3 RELATIVE TIMING ACCURACY IN DEGREES RELATIVE TIMING ACCURACY IN DEGREES 1.0 0.75 AIR GAP IN MILLIMETERS AIR GAP IN MILLIMETERS +2 +1 0 RISING EDGE -1 AIR GAPS 0.5 mm 1.0 mm 1.5 mm 2.0 mm 2.5 mm -2 -3 +2 +1 0 FALLING EDGE -1 AIR GAPS 0.5 mm 1.0 mm 1.5 mm 2.0 mm 2.5 mm -2 -3 0 1000 2000 3000 4000 5000 REFERENCE TARGET SPEED IN RPM 6 -40°C +25°C +150°C 50.5 -40°C +25°C +150°C DUTY CYCLE IN PER CENT DUTY CYCLE IN PER CENT 50.5 6000 7000 Dwg. GH-064-1 0 1000 2000 3000 4000 5000 REFERENCE TARGET SPEED IN RPM 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 6000 7000 Dwg. GH-064-2 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR CRITERIA FOR DEVICE QUALIFICATION All Allegro sensors are subjected to stringent qualification requirements prior to being released to production. To become qualified, except for the destructive ESD tests, no failures are permitted. Qualification Test Test Method and Test Conditions Test Length Samples Per Lot Temperature Humidity Bias Life JESD22-A101, TA = 85°C, RH = 85% 1000 hrs 48 Bias Life JESD22-A108, TA = 150°C, TJ = 165°C 1000 hrs 48 (Surge Operating Life) JESD22-A108, TA = 175°C, TJ = 190°C 168 hrs 48 Autoclave, Unbiased JESD22-A102, TA = 121°C, 15 psig 96 hrs 48 High-Temperature (Bake) Storage Life JESD22-A103, TA = 170°C 1000 hrs 48 Temperature Cycle JESD22-A104 1000 cycles 48 -55°C to +150°C ESD, Human Body Model CDF-AEC-Q100-002 Pre/Post Reading 3 per test Test to failure Pin 3 > 1.5 kV All leads > 8 kV Comments Device biased for minimum power APPLICATIONS INFORMATION Recommended Evaluation Technique. The selfcalibrating feature of the ATS632LSA requires that a special evaluation technique be used to measure its highaccuracy performance capabilities. Installation inaccuracies are calibrated out at power on; hence, it is extremely important that the device be re-powered at each air gap when gathering timing accuracy data. Self-Calibrating Functions. These sensors are designed to minimize performance variation caused by the large air gap variations resulting from installation by selfcalibrating at power-on. They are also designed to minimize performance variation caused by the smaller, slower air gap changes resulting from temperature change and gear run-out during continuous operation by www.allegromicro.com updating the self-calibration periodically (after every 64 output pulses) if necessary. These two functions should be tested using the following procedure. 1. Set the air gap to the desired value. 2. Power down and then power on the device. 3. Rotate the target at the desired speed. 4. Wait for calibration to complete (16 output pulses to occur). 5. Monitor output for correct switching and measure accuracy. 6. Repeat the above for multiple air gaps within the operating range of the device. 7. This can be repeated over the entire temperature range. 7 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR APPLICATIONS INFORMATION — Continued Measurement of the effect of changing air gap after power on: 1. Set the air gap to the desired value (nominal, for example). Rotate the target at the desired speed. Apply power to the module. Wait for 16 output pulses to occur. Monitor output for correct switching and measure accuracy. 2. Change the air gap by ± 0.25 mm. Do not re-power module. Wait for 64 output pulses to occur. Monitor the output for correct switching and measure accuracy. Operation with Fine-Pitch Gears. The self-calibration routines allow the detection of fine-pitch gears once the target is rotating. The major issue in these applications is the impact of gear run-out on the baseline of the magnetic field. Excessive run-out may result in tooth edges not being detected. Device Switch Points. The device switch points are referenced to the peak-to-peak values of the gain-adjusted signal. The comparator thresholds have been chosen to provide timing accuracy, as well as limited immunity from mis-detection caused by short valley conditions or by gear run-out. Output. The output of the sensor is a short-circuitprotected open-collector stage capable of sinking 20 mA. An external pull-up (resistor) to a supply voltage of not more than 24 V must be supplied. Gear Design Criteria.* The system was designed to work correctly with minimum valley depths of 5 mm and minimum valley widths of 13 mm. As the valley depth decreases, the valley field rises above the open-circuit value of the magnetic circuit when the sensor is at minimum air gap. The same is true when the valley width decreases. In both cases, the metal mass from the valley bottom or side walls provides an interference at minimum air gap and will provide a signal that may be interpreted as a tooth upon power on. It is important to note that this anomaly will normally only affect the power-on state of the device and the self-calibration circuitry will null this baseline shift when the device is in running mode. * In application, the terms “gear” and “target” are often interchanged. However, “gear” is preferred when motion is transferred. Signal Duty Cycle. For regular tooth geometries, precise duty cycle is maintained over the operating air gap and temperature range due to the good symmetry of the magnetic switch points of the device. Output Polarity. The switching of the output is independent of the direction of gear rotation. Power Supply Protection. The device contains an onchip regulator and can operate over a wide supply voltage range (4.5 V to 24 V). For devices that need to operate from an unregulated power supply, transient protection must be added externally. For applications being run off a regulated line, EMI/RFI protection is still required. Incorrect protection can result in unexplained pulses on the output line, providing inaccurate sensing information to the user. Signal-Timing Accuracy. Timing accuracy is improved with larger gear diameters. The magnetic field profile has a defined spread that narrows in degrees as the target diameter increases. The slope of this magnetic profile also changes with air gap. For highest accuracy, targets greater than 100 mm diameter should be used. 8 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 continued next page… ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR APPLICATIONS INFORMATION — Continued The protection circuitry can easily be added to a PC board for use with this device. Provisions have been made for easy mounting of a PC board on the back of the unit. PC board installation parallel to the device axis is also possible. Operation From a Regulated Power Supply. These devices require minimal protection circuitry during operation from a low-voltage regulated line. The on-chip voltage regulator provides immunity to power supply variations between 4.5 V and 24 V. However, even while operating from a regulated line, some supply and output filtering is required to provide immunity to coupled and injected noise on the supply line. A basic RC low-pass filter circuit (R1C1) on the supply line and an optional output capacitor (C2) is recommended for operation in noisy environments. In extremely noisy environments, a filter capacitor at pin 3 may also be required. Because the device has an open collector output, an output pull-up resistor must be added either at the sensor module or at the controller. SUPPLY OUTPUT C2 100 pF RL 4 3 2 1 Dwg. AH-007 20 Ω R1 C1 0.033 µF 100 pF C3 1 2 3 4 Vcc X Dwg. EH-008-3A continued next page… www.allegromicro.com 9 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR APPLICATIONS INFORMATION — Continued Operation from an Unregulated Power Supply. In applications where the device gets its power from an unregulated supply such as an automotive battery, full protection is generally required. In addition to supply regulation, such applications require the device to withstand various supply side transients. Specifications for such transients vary between car manufacturers and protection circuit design should be optimized for each application. In the circuit shown below, a simple Zenercontrolled regulator is constructed using discrete components. The RC low-pass filter on the supply line (R1C1) and a low-value supply bypass capacitor (CS) can be included, if necessary, so as to minimize the susceptibility to EMI/RFI. The NPN should be chosen with sufficiently high forward breakdown voltage so as to hold off supplyside transients. The series diode should be chosen with sufficiently high reverse breakdown capabilities so as to withstand the most negative transient. The current-limiting resistor (RZ) and the Zener diode should be sized for power dissipation requirements. OUTPUT SUPPLY C2 100 pF RL 20 Ω R1 2.5 kΩ RZ 0.1 µF CS C1 0.033 µF 100 pF C3 6.8 V 1 2 3 4 Vcc X Dwg. EH-008-2A Additional applications Information on gear-tooth and other Hall-effect sensors is provided in the Allegro Integrated and Discrete Semiconductors Data Book or Application Note 27701. 10 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR MECHANICAL INFORMATION Component Material Function Units Sensor Face Thermoset epoxy Maximum temperature 170°C* Plastic Housing Polyamide, 33% glass filled 264 psi deflection temp. (DTUL) 225°C (Nylon 6, 6) Approximate melting temperature 260°C Leads Copper – – Lead Pull – – 8N Lead Finish 90/10 tin/lead solder plate – † Flame Class Rating – – UL94V-0 *Temperature excursions to 225 °C for 2 minutes or less are permitted. †All industry-accepted soldering techniques are permitted for these modules provided the indicated maximum temperature for each component (e.g., sensor face, plastic housing) is not exceeded. Reasonable dwell times, which do not cause melting of the plastic housing, should be used. Sensor Location (in millimeters) Lead Cross-Section (in millimeters) (sensor location relative to package center is the design objective) 0.48 0.36 0.41 NOM. 0.1 0.44 0.35 0.38 NOM. A Dwg. MH-018-2 mm 0.0076 MIN. PLATING THICKNESS Dwg. MH-019A mm continued next page… www.allegromicro.com 11 ATS632LSA HALL-EFFECT GEAR-TOOTH SENSOR DIMENSIONS IN MILLIMETERS 1.27 7.25 5.00 TYP 1 2 3 9.0 4 0.41 0.38 3.9 3.0 NOM 0.9 DIA A 8.3 8.0 2.0 9.0 SEE NOTE Dwg. MH-017A mm Tolerances unless otherwise specified:1 place ±0.1 mm, 2 places ±0.05 mm. NOTE — Nominal dimension and tolerances dependent on package material. Contact factory. The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro products are not authorized for use as critical components in life-support appliances, devices, or systems without express written approval. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties that may result from its use. 12 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000