3195

3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH 3195 These Hall-effect latches are capable of sensing magnetic fields while using an unprotected power supply. The A3195– 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. A 25 mA high-side driver combined with an active pull-down is especially useful for driving capacitive loads. Output short-circuit protection allows for 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. Each monolithic device contains an integrated Hall-effect transducer, a temperature-compensated comparator, a voltage regulator, and a buffered high-side driver with an active pull-down. Supply protection is made possible by the integration of overvoltage shutdown circuitry that monitors supply fault conditions. Output protection circuitry includes source and sink current current limiting for short circuits to supply or ground. The A3195E– is rated for operation over a temperature range of -40°C to +85°C; the A3195L– is rated for operation over an extended temperature range of -40°C to +150°C. They are supplied in a threelead SIP (suffix –U) or a surface-mount SOT-89 (suffix –LT). Data Sheet 27609.15* PROTECTED, HIGH-TEMPERATURE, HALL-EFFECT LATCH WITH ACTIVE PULL-DOWN X LATCH VCC 1 2 3 GROUND Dwg. PH-013 Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC (100 ms) .......... 115 V* (continuous) ................................... 26 V Reverse Battery Voltage, VRCC (100 ms) ............................ -100 V (continuous) ................................. -30 V Magnetic Flux Density, B ........... Unlimited Reverse Output Voltage, VOUT ......... -0.5 V Continuous Output Current, IOUT ........................... Internally Limited Package Power Dissipation, PD ........................................ See Graph Junction Temperature, TJ ................. 170 °C Operating Temperature Range, TA Suffix “E–” .................... -40 °C to +85°C Suffix “L–” .................. -40°C to +150°C Storage Temperature, TS ................. 170 °C *Fault condition, internal overvoltage shutdown above 28 V. OUTPUT SUPPLY FEATURES s s s s s s s s s s 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., A3195LU . 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH FUNCTIONAL BLOCK DIAGRAM 1 VCC OVERVOLT. LOCKOUT REG. LATCH X 3 OUTPUT CURRENT LIMIT Dwg. FH-013 15kΩ 2 GROUND TRANSFER CHARACTERISTICS 800 ALLOWABLE PACKAGE POWER DISSIPATION IN mW 700 600 500 400 300 200 100 VOUT(L) 26 V MAX VOUT(H) "U" PACKAGE RθJA = 183°C/W "LT" PACKAGE RθJA = 258°C/W OUTPUT VOLTAGE IN VOLTS B RP B OP 0 0 20 40 60 100 140 80 120 AMBIENT TEMPERATURE IN °C 160 180 -B 0 FLUX DENSITY +B Dwg. GH-034-3 Dwg. GH-054A 115 Northeast Cutoff, Box 15036 W Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1995, 1997, Allegro MicroSystems, Inc. 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless otherwise specified). Limits Characteristic Supply Voltage Overvoltage Shutdown* Output Voltage, High (Source Voltage) Output Voltage, Low (Sink Voltage) Output Clamp Voltage Output Current Limit Supply Current Symbol VCC VCC(OV) VOUT(H) VOUT(L) V OUT(CLMP) IOUTMAX ICC Test Conditions Operating (but VCC x ICC B > BOP B < BRP, IOUT = -20 mA B > BOP, IOUT BOP, IOUT = 5 mA B < BRP, VCC > 26 V, IOUT = 0 B < BRP, VCC = 12 V B > BOP , VOUT < 14 V B < BRP, VCC = 18 V, IOUT = 0 B > BOP , VCC = 18 V, IOUT = 0 VCC= +115 V* VRCC = -35 V* VRCC = -100 V* CL = 20 pF, RL = 330 Ω CL = 20 pF, RL = 330 Ω “LT” Package “U” Package VS Min. TA limited) 3.8 28 VCC -2 — — 15 -26 8.0 — — — — — — — — — Typ. 12 — — 0.1 0.25 18 — — 6.0 8.0 8.0 -0.1 -0.1 0.12 0.30 258 183 Max. 26 55 V CC -0.3 0.2 0.5 21 -70 25 9.0 12 17 -5.0 -10 2.0 5.0 — — Units V V V V V V mA mA mA mA mA mA mA µs µs °C/W °C/W Reverse Battery Current* Output Rise Time Output Fall Time Package Thermal Resist. IRCC tr tf 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 = Maximum TA = -40°C TA = +25° C TA = Maximum TA = -40°C TA = +25° C TA = Maximum Min. 60 50 40 -200 -160 -150 150 130 110 Typ. 125 110 100 -125 -110 -100 250 220 200 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: Negative current is defined as coming out of (sourcing) the output. 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 T A = +25° C and VCC = 12 V. * Fault condition. Device is shut down and operation is not possible. 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH TYPICAL OPERATING CHARACTERISTICS 200 Vcc OPERATE POINT Vcc - 1 OUTPUT VOLTAGE IN VOLTS 100 SWITCH POINTS IN GAUSS OUTPUT HIGH, B ≤ B RP (SOURCING CURRENT) I OUT = -20 mA Vcc - 2 VCC = 16 V 0.4 I OUT = 5 mA 0 VCC = 3.8 V–26 V -100 RELEASE POINT 0.2 OUTPUT LOW, B ≥ B OP (SINKING CURRENT) I OUT ≤ 100 µA -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-052-1 AMBIENT TEMPERATURE IN °C Dwg. GH-040-2 TYPICAL OPERATING CHARACTERISTICS Output Current Limit 20 9.0 OUTPUT LOW, B ≥ B OP (SINKING CURRENT) 0 8.0 SUPPLY CURRENT IN mA CURRENT LIMIT IN mA VCC = 26 V -20 VCC = 16 V 7.0 VCC = 12 V -40 OUTPUT HIGH, B ≤ B RP (SOURCING CURRENT) -60 -50 6.0 VCC = 3.8 V OUTPUT HIGH, B ≥ B OP OUTPUT LOW, B ≤ B RP -25 0 25 50 75 100 125 150 5.0 -50 -25 0 25 50 75 100 125 150 AMBIENT TEMPERATURE IN °C Dwg. GH-004-1 AMBIENT TEMPERATURE IN °C Dwg. GH-028-2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH 3.8 V TO 26 V WITH TRANSIENTS VCC 1 C BYPASS X 3 TO µP CL RL 2 Dwg. EH-007 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 An external 0.1 µF to 0.47 µF capacitor, with good high-frequency characteristics, should be connected between terminals 1 and 2 to bypass high-voltage noise and reduce EMI susceptibility. Internal Pull-Down Resistor. An internal pull-down resistor (nominal 15 kΩ ) is provided to allow testing of the device without the need for an external load. 20 18 PULL-DOWN RESISTANCE IN kΩ 16 14 12 10 -50 -25 0 25 50 75 100 125 150 AMBIENT TEMPERATURE IN °C Dwg. GH-060 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH INTERNAL PROTECTIVE FEATURES ISO Pulse No. 1 2 3a 3b 4 5 Test Conditions (at TA = +25°C) VS = -100 V, RS = 10 Ω, tr = 1 µs, t d = 2 ms VS = 90 V, RS = 10 Ω, t r = 1 µ s, td = 50 µs VS = -150 V, RS = 50 Ω, tr = 50 ns, td = 100 ns VS = 100 V, RS = 50 Ω, tr = 50 ns, td = 100 ns VS = -14 V, td = 20 s VS = 86.5 V, RS = 0.5 Ω, tr = 5 ms, td = 400 ms VS = 120 V, RS = 0.5 Ω, tr = 100 ns, t d = 400 ms VS = -300 V, RS = 30 Ω, tr = 60 µs, t d = 300 µ s VS = -80 V, RS = 10 Ω, tr = 5 ms, td = 100 ms Test Inductive Turn Off (Negative) Inductive Turn Off (Positive) Capacitive/Inductive Coupling (Neg) Capacitive/Inductive Coupling (Pos) Reverse Battery Load Dump (ISO) (DIN) 6 7 Ignition Coil Disconnect EXTERNAL PROTECTION REQ’D Field Decay (Negative) 0.9 V S output transistor will be thermally stressed. Current through the active pull-down is limited to between 8 mA and 25 mA. VS 0.1 V 12 V 0 S tr td Dwg WH-008 Power supply voltage transients, or device output short circuits, may be caused by faulty connectors, crimped wiring harnesses, or service errors. To prevent catastrophic failure, internal protection against overvoltage, reverse voltage, output overloads have been incorporated to meet the automotive 12 volt system protection requirements of ISO DP7637/1 and DIN 40839-1. A series-blocking diode or current-limiting resistor is required in order to survive pulse number six. Output Overloads. Current through the output source transistor is sensed with a low-value on-chip aluminum resistor. The voltage drop across this resistor is fed back to control the base drive of the output stage. This feedback prevents the output transistor from exceeding its maximum current density rating by limiting the output current to between -26 mA and -70 mA. Under short-circuit conditions, the device will dissipate an increased amount of power (PD = VOUT x ILIMIT) and the Overvoltage. The device protects itself against high-voltage transients by shutting OFF the output source driver and all supplyreferenced active components, reducing the supply current, and minimizing device power dissipation. Overvoltage shutdown can occur anywhere between 28 V and 55 V and device operation above 28 V cannot be recommended. The device will continue to operate, with increased power dissipation, for supply voltages above the internal clamp voltage but below the overvoltage shutdown. Under a sustained overvoltage, the device may be required to dissipate an increased amount of power (PD = VCC x ICC ) and the device may be thermally stressed (see above). Output Voltage. The output is clamped with an on-chip Zener diode to prevent supply overvoltage faults from appearing at the output when the field is less than BRP. When any fault condition is removed, the device returns to normal operating mode. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH 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. Test Method and Test Conditions JESD22-A101 TA = 85°C, RH = 85% JESD22-A108 TA = 150°C, T J = 165 °C JESD22-A108 TA = 175°C, T J = 190 °C JESD22-A102, Method C MIL-STD-883, Method 1008 TA = 170°C MIL-STD-883, Method 1010 MIL-STD-883, Method 3015 No. of Lots 3 3 1 3 1 3 1 1 Samples Per Lot 116 116 116 77 77 153 3 per test 3 per test Test to failure HBM ≥ 12 kV Test to failure MM ≥ 600 V Qualification Test Biased Humidity High-Temperature Operating Life Surge Operating Life Pressure Cooker, Unbiased Storage Life Temperature Cycle ESD Human Body Model ESD Machine Model Test Length 1200 hrs 1200 hrs 504 hrs 96 hrs 1200 hrs 1000 cycles Pre/Post Reading Pre/Post Reading Comments Device biased for minimum power 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH SENSOR LOCATIONS (±0.005" [0.13 mm] die placement) SUFFIX “LT” ACTIVE AREA DEPTH 0.030" 0.76 mm NOM APPLICATIONS INFORMATION The A3195– latch has 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. Short-circuit protection is included to prevent damage caused by pinched wiring harnesses. An on-chip pull-down resistor is provided to allow device testing without the connection of the control module. 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 also available in the Allegro Integrated and Discrete Semiconductors Data Book or Application Note 27701. 0.087" 2.21 mm 0.051" 1.30 mm A 1 2 3 Dwg. MH-008-6A SUFFIX “U” ACTIVE AREA DEPTH 0.015" 0.38 mm NOM 0.089" 2.26 mm 0.073" 1.85 mm A BRANDED SURFACE 1 2 3 Dwg. MH-002-13A 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH A3195ELT AND A3195LLT Dimensions in Inches (for reference only) 0.173 0.181 0.064 0.072 0.155 0.167 0.090 0.102 0.055 0.063 0.014 0.017 1 2 3 0.084 0.090 0.035 0.047 0.059 BSC 0.014 0.019 0.017 0.022 0.118 BSC Dwg. MA-009-3 in Dimensions in Millimeters (controlling dimensions) 4.40 4.60 1.62 1.83 3.94 4.25 2.29 2.60 1.40 1.60 0.35 0.44 1 2 3 2.13 2.29 0.89 1.20 1.50 BSC 0.36 0.48 0.44 0.56 3.00 BSC Dwg. MA-009-3 mm NOTE — Exact body and lead configuration at vendor’s option within limits shown. 3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH A3195EU AND A3195LU Dimensions in Inches (controlling dimensions) 0.183 0.178 0.063 0.059 Dimensions in Millimeters (for reference only) 4.65 4.52 1.60 1.50 0.181 0.176 45° 0.086 MAX 4.60 4.47 45° 2.18 MAX 1 2 3 0.018 1 2 3 0.46 0.600 0.560 0.016 SEE NOTE 0.015 15.24 14.23 0.41 SEE NOTE 0.38 0.050 0.100 Dwg. MH-003D in 1.27 2.54 Dwg. MH-003D 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. 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 design of its products. 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 which may result from its use. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000