ATS651LSH

ATS651LSH Two-Wire Self-Calibrating Differential Speed and Direction Sensor with Vibration Immunity The ATS651LSH is a mechatronics component with an integrated Hall-effect sensor and magnet, providing an easy-to-use solution for speed and direction sensing applications. The solid thermoset molded plastic package contains a samarium cobalt magnet and a Hall-effect IC optimized to the magnetic circuit. This sensor module has been designed specifically for high reliability in the harsh automotive environment. The IC employs patented algorithms for the special operational requirements of transmission applications. This two-wire device communicates the speed and direction of a ferrous target via a pulse width modulation (PWM) output protocol. The innovative dual differential detector scheme uses three Hall elements and two separate signal processing channels. This provides greater reliability than conventional designs. Because only one of the channels controls switching, the same edge of each tooth is used for determining output signals, in both forward and reverse target rotation, with direction information available on the first magnetic edge after a direction change. The ATS651LSH is particularly adept at handling vibration without sacrificing maximum air gap capability or creating an erroneous “direction” pulse. Even the higher angular vibration caused by engine cranking is completely rejected by the device. The advanced vibration detection algorithms systematically calibrate the sensor on the true rotation signals from the first three and a half teeth, not on vibration, thus always guaranteeing an accurate signal in running mode. Patented running mode algorithms also protect against air gap changes, whether or not the target is in motion. Advanced signal processing and innovative algorithms make the ATS651LSH an ideal solution for a wide range of speed and direction sensing needs. The device package is lead (Pb) free, with 100% matte tin plated leadframe. Package SH 12 34 1. VCC 2. TESTA pin, Channel A 3. TESTB pin, Channel B 4. GND Features and Benefits • • • • • • • • • • • • Rotational direction detection Fully optimized digital differential gear-tooth sensor Single-chip sensing IC for high reliability Small mechanical size (8 mm diameter × 5.5 mm vertical, flat-to-flat) Internal current regulator for 2-wire operation Automatic Gain Control (AGC) and reference adjust circuit 3-bit factory trimmed for tight pulse width accuracy True zero-speed operation Wide operating voltage range Undervoltage lockout Defined power-on state ESD and reverse polarity protection Part Number ATS651LSHTN-T Packing* 13-in. reel, 800 pieces/reel ABSOLUTE MAXIMUM RATINGS Supply Voltage*, VCC ......................................... 28 V Reverse-Supply Voltage, VRCC ........................ –18 V Reverse-Output Voltage, VROUT...................... –0.5 V Temperatures Operating Ambient, TA................. –40ºC to 150ºC Junction, TJ(MAX) .......................................165ºC Storage, TS ................................. –65ºC to 170ºC *Refer to Power Derating section Use the following complete part numbers when ordering: *Contact Allegro for additional packing options. Some restrictions may apply to certain types of sales. Contact Allegro for details. 651LSH-DS, Rev. 3 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com ATS651LSH Two-Wire Self-Calibrating Differential Speed and Direction Sensor with Vibration Immunity Functional Block Diagram V+ VCC Voltage Regulator Hall Element 1 Channel A 0.01μF CBYPASS Hall Amp Hall Element 2 NDAC Offset Adjust AGC PDAC PThresh Reference Generator and Updates NThresh PThresh Threshold Logic Channel B Hall Element 3 Hall Amp Offset Adjust AGC PDAC Reference Generator and Updates NDAC NThresh Threshold Logic Speed and Direction Logic Current Output Adjust GND (Recommended) (Recommended) TESTA TESTB Typical Application Diagram ECU ICC(HIGH)/ICC(LOW) 1 2 ATS651 3 0.01 μF CBYPASS 4 Note: Pins 2 and 3 may be connected to pin 4. However, ICC is increased in that configuration. 100 Ω RSENSE CSENSE 651LSH-DS, Rev. 3 Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 2 ATS651LSH Two-Wire Self-Calibrating Differential Speed and Direction Sensor with Vibration Immunity Device Characteristics Tables ELECTRICAL CHARACTERISTICS Valid for –40°C ≤ TA ≤ 150°C, TJ ≤ 165°C, unless otherwise noted Characteristics Supply Voltage Undervoltage Lockout Reverse Supply Current Supply Zener Clamp Voltage Supply Zener Resistance Output Current Slew Rate Power-On State Power-On Time1 Supply Current Supply Current Difference Symbol VCC VCC(UV) IRCC VZ RZ SRI POS tPO ICC(Low) ICC(High) ΔICC I(High) → I(Low) , I(Low) → I(High) RSENSE = 100 Ω, CSENSE = 10 pF, 10 to 90% points ION state Gear speed < 100 rpm Low-current state High-current state ICC(High) - ICC(Low); difference between high-current state level and low-current state level First output transition First output transition Running mode direction change Over four edges Running, TJ ≤ 165°C VCC = 5 → 0 V VCC = –18 V ICC(Low)max + 3 mA Test Conditions Min. 4.3 – – 28 – 2 – – 4 12 5.3 Typ. – – – – 20 16 ICC(Low) – 7 14.5 – Max. 24 4.3 –10 40 – – – 1 9 17 – Units V V mA V Ω mA/μs mA ms mA mA mA CALIBRATION Direction Information2 Speed Information2 Direction Change Signal Variation4 (At calibration) Detection3 NDir NSpd NCD ECAL – – – – – – – – 8 8 1 ±0.3 Edge Edge Edge mm DAC CHARACTERISTICS Dynamic Offset Cancellation5 1Power-On 2Edge As shipped – ±60 – G Time is the time required to complete the internal automatic offset adjust; the DACs are then ready for peak acquisition. count is based on mechanical edges. First output edge is available on or before NDir or NSpd edges. 3Edge count is based on mechanical edges. On the N CD edge, direction and speed information is valid. 4If the peak-to-peak amplitude of the signal varies more than the specified amount during the direction verification process, then additional edges may be required for calibration. 5The device will compensate for magnetic and installation offsets up to ±60 gauss. Offsets greater than ±60 gauss may cause inaccuracies in the output. OPERATING CHARACTERISTICS Using Reference Target 60-0 and valid over operating temperature range Characteristics Operational Air Gap Range* Operating Signal Range *Operational Air Symbol AGOP Sig Within specification Within specification Test Conditions Min. 0.5 30 Typ. – – Max. 2.8 1200 Units mm G Gap Range is dependent on the available differential 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 Parameters section of this datasheet. Continued on the next page... Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com 3 651LSH-DS, Rev. 3 ATS651LSH Two-Wire Self-Calibrating Differential Speed and Direction Sensor with Vibration Immunity Device Characteristics Tables (Continued) SWITCHING CHARACTERISTICS Valid for –40°C ≤ TA ≤ 150°C, TJ ≤ 165°C, unless otherwise noted Characteristics Operate Point Release Point Axial/Radial Runout1 (Multiple teeth) Sudden Air Gap (Single tooth) Incremental Air Gap (Consecutive edges) Vibration Immunity (At power-on) Vibration Immunity2 (Running) Maximum Operating Frequency3 1Inclusive 2Device Symbol BOP BRP ROA/R ΔAGSAG ΔAGIR+ ΔAGIRROTVIBS ROTVIBR ffwd frev Test Conditions % of peak-to-peak referenced from PDAC to NDAC, AGOP < AGOP(max) % of peak-to-peak referenced from PDAC to NDAC, AGOP < AGOP(max) Min. – – – Typ. 58 42 – – – – – – – – Max. – – ±1.75 ±0.4 ±0.1 ±0.15 ±0.2 ±0.75 ±0.35 – – Units % % mm mm mm mm mm (°) (°) kHz kHz Instantaneous air gap change (8 kHz Air gap change between edges @ 8-4 kHz Air gap change between edges @