A3197LLT

3197 PROTECTED, HIGH-TEMPERATURE, OPEN-COLLECTOR HALL-EFFECT LATCH These open-collector Hall-effect latches are capable of sensing magnetic fields while using an unprotected power supply. The A3197LLT and A3197LU can provide position and speed information by providing a digital output for magnetic fields that exceed their predefined switch points. These devices operate down to zero speed and have switch points that are designed to be extremely stable over a wide operating temperature and voltage range. The latching characteristics make them ideal for use in pulse counting applications when used with a multi-pole ring magnet. Thermal and output short-circuit protection allow an increased wiring harness fault tolerance. The temperature compensated switch points, the wide operating voltage range, and the integrated protection make these devices ideal for use in automotive applications such as transmission speed sensors and integrated wheel bearing speed sensors. 3 Data Sheet 27609.10A X PTCT V CC 1 2 Dwg. PH-003-2 Each monolithic device contains an integrated Hall-effect transducer, a temperature-compensated comparator, a voltage regulator, and a buffered 35 mA output sink stage. Supply protection is made possible by the integration of overvoltage and undervoltage shutdown circuitry that monitor supply fault conditions and shut down the IC. Noise shutdown circuitry (patent applied for) prevents the propagation of supply transients to the logic load. Output protection circuitry includes a current limit loop that limits the maximum output sink current, and thermal protection circuitry that shuts down the device during an over-heating condition such as with a shorted load. The A3197LLT and A3197LU are rated for operation over an extended temperature range of -40°C to +150°C. They are supplied in a three-lead SIP (suffix ‘U’) or a surface-mount SOT-89 (suffix ‘LT’). GROUND ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC (100 ms) ................................... 115 V* (continuous) ............................... 28 V* Reverse Battery Voltage, VRCC (100 ms) ................................... -100 V (continuous) ............................... -35 V Magnetic Flux Density, B .......... Unlimited Output OFF Voltage, VOUT ................. 26 V Reverse Output Voltage VOUT ......... -0.5 V Continuous Output Current, IOUT .......................................... 35 mA* Reverse Output Current, IOUT ........................................ -100 mA Package Power Dissipation, PD ....................................... See Graph Junction Temperature, TJ ................. 170°C Operating Temperature Range, TA .......................................... -40°C to +150°C Storage Temperature, TS .................. 170°C *Fault condition, internal overvoltage shutdown above 28 V; output current limited above 35 mA. OUTPUT SUPPLY FEATURES I I I I I I I I I I Internal Protection For Automotive (ISO/DIN) Transients Operation From Unregulated Supply Reverse Battery Protection Undervoltage Lockout Supply Noise-Suppression Circuitry Output Short-Circuit Protection Output Zener Clamp Thermal Protection Symmetrical Latching Switch Points Operable with Multipole Ring Magnets Always order by complete part number, e.g., A3197LU . 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH FUNCTIONAL BLOCK DIAGRAM 1 VCC OVERVOLT. LOCKOUT REG. POWER UP & TRANSIENT PROTECTION 3 OUTPUT CONTROL X THERMAL SHUTDOWN CURRENT LIMIT BOP B > BOP B > BOP, IOUT = 30 mA, VCC = 16 V VOUT = 26 V B < BRP, VCC = 115 V*, IOUT = 0 B > BOP, VOUT = 12 V B < BRP, VCC = 24 V, IOUT = 0 B > BOP, VCC = 24 V, IOUT = 20 mA VCC = +115 V* VRCC = -35 V* VRCC = -100 V* CL = 20 pF, RL = 330 Ω, VBB = 12 V CL = 20 pF, RL = 330 Ω, VBB = 12 V Min. VCC(UV) 28 3.7 — — 28 35 — — — — — — — 165 “LT” Package “U” Package — — Typ. 12 — — 0.2 — 32 50 5.2 7.8 8.0 -0.5 -2.0 0.05 0.30 — 258 183 Max. 26 55 4.5 0.5 5.0 40 70 9.0 12 17 -5.0 -10 2.0 5.0 190 — — Units V V V V µA V mA mA mA mA mA mA µs µs °C °C/W °C/W Reverse Battery Current* Output Rise Time Output Fall Time Thermal Shutdown Temp.* Package Thermal Resist. IRCC tr tf TJ RθJA MAGNETIC CHARACTERISTICS over operating voltage range (unless otherwise specified). Limits Characteristic Operate Point Symbol BOP Test Conditions TA = -40°C TA = +25°C TA = +150°C TA = -40°C TA = +25°C TA = +150°C TA = -40°C TA = +25°C TA = +150°C Min. 60 50 40 -200 -160 -150 150 130 110 Typ. 130 110 105 -140 -120 -100 270 230 205 Max. 200 160 150 -60 -50 -40 — — — Units G G G G G G G G G Release Point BRP Hysteresis (BOP - BRP) Bhys NOTES: BOP = magnetic operate point (output turns ON); BRP = magnetic release point (output turns OFF). As used here, negative flux densities are defined as less than zero (algebraic convention). Typical values are at TA = +25°C and VCC = 12 V (unless otherwise specified). * Fault condition. Device is shut down and operation is not possible. www.allegromicro.com 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH TYPICAL OPERATING CHARACTERISTICS Switch Points 200 Output Saturation Voltage 500 OPERATE POINT 400 SATURATION VOLTAGE IN mV VCC = 12 V B ≥ BOP 100 SWITCH POINTS IN GAUSS 300 0 VCC = 5 V–24 V 200 IOUT = 30 mA -100 RELEASE POINT 100 I OUT = 5 mA -200 -50 -25 0 25 50 75 100 125 150 0 -50 -25 0 25 50 75 100 125 150 AMBIENT TEMPERATURE IN °C Dwg. GH-052-2 AMBIENT TEMPERATURE IN °C Dwg. GH-040-3 Supply Current 8.0 B ≥ B OP SUPPLY CURRENT IN mA VCC = 24 V 7.0 V CC= 5 V 6.0 VCC = 24 V 5.0 B ≤ B RP VCC = 5 V 4.0 -50 -25 0 25 50 75 100 125 150 AMBIENT TEMPERATURE IN °C Dwg. GH-028-3 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH OPERATION In operation, the output transistor is OFF until the strength of the magnetic field perpendicular to the surface of the chip exceeds the threshold or operate point (BOP). When the field strength exceeds BOP, the output transistor switches ON (a logic low) and is capable of sinking 35 mA of current. The output transistor switches OFF (a logic high) when magnetic field reversal results in a magnetic flux density below the OFF threshold (BRP). This is illustrated in the transfer characteristics graph. Note that the device latches; that is, a south pole of sufficient strength will turn the device ON. Removal of the south pole will leave the device ON. The presence of a north pole of sufficient strength is required to turn the device OFF. The switch points increase in sensitivity with increasing temperature to compensate for the typical ferrite magnet temperature characteristic. The simplest form of magnet that will operate these devices is a ring magnet. Other methods of operation are possible. TEST CIRCUIT AND TYPICAL APPLICATION VCC(UV) TO 26 V WITH TRANSIENTS VCC 1 REGULATED < 26 V VBB RL 3 TO µP CBYPASS X CL 2 Dwg. EH-006A 26 V MAX VBB OUTPUT VOLTAGE IN VOLTS B RP B OP VOUT(SAT) 0 -B 0 FLUX DENSITY +B Dwg. GH-034-2A www.allegromicro.com 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH Power Up Reset. These devices are designed to power up with the output OFF without regard to any magnetic field applied. The output will remain OFF until the flux is reduced to below BRP (S-N transition) and then BOP is exceeded, depending on the turn-on state of the internal latches. +B 0 -B VCC 0 FIRST BOP AFTER POWER UP VOUT VOUT(SAT) Dwg. WH-006 BOP BRP Power Supply Transients (Noise); Overvoltage and Undervoltage Lockout. Even in protected devices, positive and negative power supply transients that would not normally cause physical damage can cause logic errors in control systems. The A3197LT and A3197LU include noise suppression features to prevent this. In a typical application, where the output is externally pulled up to a regulated voltage 16 kV Test to failure MM > 800 V 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH (±0.005" [0.13 mm] die placement) SENSOR LOCATIONS SUFFIX “LT” APPLICATIONS INFORMATION The A3197LLT and A3197LU latches have been optimized for use in automotive ring magnet sensing applications. Such applications include transmission speed sensors, motor position encoders, and wheel bearing speed sensors. Special care has been taken to optimize the operation of these devices in automotive subsystems that require ISO DP9637 protection but NOT operation. Undervoltage lockout is included to prevent propagation of false logic pulses during low battery, cold-start conditions. Noise suppression is included to prevent false switching of the device when subjected to ISO transients. Short-circuit protection is included to prevent damage caused by pinched wiring harnesses. A typical application consists of a ferrite ring magnet located on a rotating shaft. Typically, this shaft is attached to the transmission, the sensor is mounted on a board, with care being taken to keep a tight tolerance on the air gap between the package face and the magnet. The device will provide a change in digital state at the transition of every magnetic pole and, thus, give an indication of the transmission speed. The high magnetic hysteresis allows the device to be immune to vibration of the magnet shaft and relatively good duty cycles can be obtained. Hall effect applications information is available in the “Hall-Effect IC Applications Guide”, which can be found in the Allegro MicroSystems Electronic Data Book, AMS-702, or Application Note 2770, or at ACTIVE AREA DEPTH 0.030" 0.76 mm NOM 0.092" 2.35 mm 0.051" 1.30 mm A 1 2 3 Dwg. MH-008-5A SUFFIX “U” ACTIVE AREA DEPTH 0.015" 0.38 mm NOM 0.094" 2.40 mm 0.073" 1.85 mm www.allegromicro.com. A BRANDED SURFACE 1 2 3 Dwg. MH-002-12A www.allegromicro.com 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH A3197ELT and A3197LLT Dimensions in Inches (for reference only) 0.181 0.173 0.072 0.064 0.167 0.155 0.102 0.090 0.063 0.055 0.0173 0.0138 1 2 3 0.090 0.084 0.047 0.035 0.059 BSC 0.0189 0.0142 0.0221 0.0173 0.118 BSC Dwg. MA-009-3A in Dimensions in Millimeters (controlling dimensions) 4.60 4.40 1.83 1.62 4.25 3.94 2.60 2.29 1.60 1.40 0.44 0.35 1 2 3 2.29 2.13 1.20 0.89 1.50 BSC 0.48 0.36 0.56 0.44 3.00 BSC Dwg. MA-009-3A mm NOTE — Exact body and lead configuration at vendor’s option within limits shown. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH A3197EU and A3197LU Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) 0.183 0.178 0.063 0.059 4.65 4.52 1.60 1.50 0.181 0.176 45° 0.086 MAX 1 2 3 4.60 4.47 45° 2.18 MAX 1 2 3 0.018 0.46 0.600 0.560 0.0189 0.0142 SEE NOTE 0.0173 0.0138 15.24 14.23 0.48 0.36 SEE NOTE 0.44 0.35 0.050 0.100 Dwg. MH-003E in 1.27 2.54 Dwg. MH-003E mm NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are measured at the widest point (parting line). 2. Exact body and lead configuration at vendor’s option within limits shown. 3. Height does not include mold gate flash. 4. Recommended minimum PWB hole diameter to clear transition area is 0.035" (0.89 mm). 5. Where no tolerance is specified, dimension is nominal. www.allegromicro.com 3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH 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. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000