3195

3195_02 ALLEGRO

Document overview

• Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 10

Technical content

PROTECTED, HIGH-TEMPERATURE, HALL-EFFECT LATCH WITH ACTIVE PULL-DOWN Always order by complete part number, e.g., A3195LU . 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 mag- netic 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 espe- cially useful for driving capacitive loads. Output short-circuit protection allows for an increased wiring harness fault tolerance. The tempera- ture compensated switch points, the wide operating voltage range, and the integrated protection make these devices ideal for use in automo- tive applications such as transmission speed sensors and integrated wheel bearing speed sensors. Each monolithic device contains an integrated Hall-effect trans- ducer, 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 three- lead SIP (suffix –U) or a surface-mount SOT89 (suffix –LT).

FEATURES

I Internal Protection For Automotive (ISO/DIN) Transients I Operation From Unregulated Supply I Reverse Battery Protection I Undervoltage Lockout I Supply Noise-Suppression Circuitry I Output Short-Circuit Protection I Output Zener Clamp I Thermal Protection I Symmetrical Latching Switch Points I Operable with Multipole Ring Magnets Dwg. PH-013 1SUPPLY VCC GROUND OUTPUT X LATCH ABSOLUTE MAXIMUM RATINGS Reverse Battery Voltage, Continuous Output Current, Package Power Dissipation, Operating Temperature Range, TA *Fault condition, internal overvoltage shutdown above 28 V. †Internal current limiting is intended to protect the device from output short circuits. Data Sheet27609.15‡ Pinning is shown viewed from branded side.

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-50002 FUNCTIONAL BLOCK DIAGRAM REG. OUTPUT3 GROUND2 X Dwg. FH-013 VCC1 CURRENT LIMIT 15kΩ OVERVOLT. LOCKOUT LATCH 26 V MAX 0+ B OUTPUT VOLTAGE IN VOLTS FLUX DENSITY Dwg. GH-034-3 RPB VOUT(L) VOUT(H) OPB TRANSFER CHARACTERISTICS 600 400 200 700 500 300 100 800 40 80 120 160 AMBIENT TEMPERATURE IN °°°°C ALLOWABLE PACKAGE POWER DISSIPATION IN MILLIWATTS Dwg. GH-054B Suffix "–U" R θJA = 183°C/W 60 100 140 18020 Suffix "L–" Suffix "E–" Suffix "–LT" R θJA = 180°C/W Copyright © 1995, 2002 Allegro MicroSystems, Inc.

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH www.allegromicro.com 3

ELECTRICAL CHARACTERISTICS

over operating voltage and temperature range (unless otherwise specified). Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Supply Voltage V CC Operating (but VCC x ICC VS TA limited) 3.8 12 26 V Overvoltage Shutdown* V CC(OV) B > BOP 28 — 55 V Output Voltage, High V OUT(H) B < BRP, IOUT = -20 mA V CC -2 — VCC -0.3 V (Source Voltage) Output Voltage, Low V OUT(L) B > BOP, IOUT <100 µA — 0.1 0.2 V (Sink Voltage) B > B OP, IOUT = 5 mA — 0.25 0.5 V Output Clamp Voltage V OUT(CLMP) B < BRP , VCC > 26 V, IOUT = 0 15 18 21 V Output Current Limit I OUTMAX B < BRP , VCC = 12 V -26 — -70 mA B > BOP , VOUT < 14 V 8.0 — 25 mA Supply Current I CC B < BRP , VCC = 18 V, IOUT = 0 — 6.0 9.0 mA B > BOP , VCC = 18 V, IOUT = 0 — 8.0 12 mA VCC = +115 V* — 8.0 17 mA Reverse Battery Current* I RCC VRCC = -35 V* — -0.1 -5.0 mA VRCC = -100 V* — -0.1 -10 mA Output Rise Time t r C L = 20 pF, RL = 330 Ω — 0.12 2.0 µs Output Fall Time t f C L = 20 pF, RL = 330 Ω — 0.30 5.0 µs Package Thermal Resist. R θJA “LT” Package — 258 — °C/W “U ” Package — 183 — °C/W MAGNETIC CHARACTERISTICS over operating voltage range (unless otherwise specified). Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Operate Point B OP TA = -40°C 60 125 200 G TA = +25°C 50 110 160 G TA = Maximum 40 100 150 G Release Point B RP TA = -40°C -200 -125 -60 G TA = +25°C -160 -110 -50 G TA = Maximum -150 -100 -40 G Hysteresis B hys TA = -40°C 150 250 — G (BOP - BRP )T A = +25°C 130 220 — G TA = Maximum 110 200 — G 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. 1 gauss (G) is exactly equal to 0.1 millitesla (mT). * Fault condition. Device is shut down and operation is not possible.

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH Worcester, Massachusetts 01615-0036 (508) 853-50004 TYPICAL OPERATING CHARACTERISTICS 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-004-1 125-25 -20 -40 -60 OUTPUT LOW, (SINKING CURRENT) B ≥ B OP OUTPUT HIGH, (SOURCING CURRENT) B ≤ B RP 150 CCV = 16 V CURRENT LIMIT IN mA 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-052-1 125-25 SWITCH POINTS IN GAUSS 200 100 -100 -200 RELEASE POINT OPERATE POINT 150 CCV = 3.8 V–26 V 9.0 SUPPLY CURRENT IN mA 8.0 7.0 6.0 5.0 0 2 55 07 51 0 0 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-028-2 125-25 V = 26 VCC 150 V = 12 VCC V = 3.8 VCC OUTPUT HIGH, B ≥ B OP OUTPUT LOW, B ≤ B RP 0 25 50 75 100 Vcc AMBIENT TEMPERATURE IN °°°°C Vcc - 1 0.4 -50 Dwg. GH-040-2 OUTPUT VOLTAGE IN VOLTS 150-25 125 Vcc - 2

0.2 OUTPUT LOW,

(SINKING CURRENT) B ≥ B OP OUTPUT HIGH, (SOURCING CURRENT) B ≤ B CCV = 16 V I = 5 mAOUT I ≤ 100 µAOUT I = -20 mA RP OUT TYPICAL OPERATING CHARACTERISTICS Output Current Limit

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH www.allegromicro.com 5 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 (B OP ). 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 (B RP ). This is illustrated in the transfer characteristics graph (page 2). 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.

3.8 V TO 26 V

Dwg. EH-007 LR TO µP LC X BYPASSC 0 25 50 75 100 AMBIENT TEMPERATURE IN °°°°C -50 Dwg. GH-060 PULL-DOWN RESISTANCE IN k ΩΩΩΩ 150-25 125

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH Worcester, Massachusetts 01615-0036 (508) 853-50006 INTERNAL PROTECTIVE FEATURES ISO Pulse No. Test Test Conditions (at T A = +25°C)

1 Inductive Turn Off (Negative) V S = -100 V, RS = 10 Ω , tr = 1 µs, td = 2 ms

2 Inductive Turn Off (Positive) V S = 90 V, RS = 10 Ω , tr = 1 µs, td = 50 µs

3a Capacitive/Inductive Coupling (Neg) V S = -150 V, RS = 50 Ω , tr = 50 ns, td = 100 ns 3b Capacitive/Inductive Coupling (Pos) V S = 100 V, RS = 50 Ω , tr = 50 ns, td = 100 ns

4 Reverse Battery V S = -14 V, td = 20 s

5 Load Dump (ISO) V S = 86.5 V, RS = 0.5 Ω , tr = 5 ms, td = 400 ms (DIN) V S = 120 V, RS = 0.5 Ω , tr = 100 ns, td = 400 ms

6 Ignition Coil Disconnect V S = -300 V, RS = 30 Ω , tr = 60 µs, td = 300 µs

EXTERNAL PROTECTION REQ ’D

7 Field Decay (Negative) V S = -80 V, RS = 10 Ω , tr = 5 ms, td = 100 ms

output transistor will be thermally stressed. Current through the active pull-down is limited to between 8 mA and 25 mA. Overvoltage. The device protects itself against high-voltage transients by shutting OFF the output source driver and all supply- referenced 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 over- voltage shutdown. Under a sustained overvoltage, the device may be required to dissipate an increased amount of power D = 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 B RP . When any fault condition is removed, the device returns to normal operating mode. 12 V V S tr td 0.9 V 0.1 V S S 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 (P D = VOUT x ILIMIT) and the

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH www.allegromicro.com 7 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 No. of Samples Qualification Test Test Conditions Lots Test Length Per Lot Comments Biased Humidity JESD22-A101 3 1200 hrs 116 Device biased for TA = 85°C, RH = 85% minimum power High-Temperature JESD22-A108 3 1200 hrs 116 Operating Life T A = 150°C, TJ = 165°C Surge Operating Life JESD22-A108 1 504 hrs 116 TA = 175°C, TJ = 190°C Pressure Cooker, JESD22-A102, Method C 3 96 hrs 77 Unbiased Storage Life MIL-STD-883, Method 1008 1 1200 hrs 77 TA = 170°C Temperature Cycle MIL-STD-883, Method 1010 3 1000 cycles 153 ESD MIL-STD-883, Method 3015 1 Pre/Post 3 per Test to failure Human Body Model Reading test HBM ≥ 12 kV ESD 1 Pre/Post 3 per Test to failure Machine Model Reading test MM ≥ 600 V 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; 5,686,894; 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 responsi- bility for its use; nor for any infringements of patents or other rights of third parties that may result from its use.

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH Worcester, Massachusetts 01615-0036 (508) 853-50008 SENSOR LOCATIONS (±0.005" [0.13 mm] die placement) A 1 32 Dwg. MH-008-6B 0.0305" 0.775 mm NOM ACTIVE AREA DEPTH 0.051" 1.30 mm 0.087" 2.21 mm SUFFIX “LT” 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 at- tached 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. SUFFIX “U” 1 32 Dwg. MH-002-13B 0.0165" 0.42 mm NOM BRANDED SURFACE ACTIVE AREA DEPTH 0.073" 1.85 mm 0.089" 2.26 mm A Extensive applications information for Hall-effect sensors is available in:

• Hall-Effect IC Applications Guide, Application Note 27701;
• Hall-Effect Devices: Soldering, Gluing, Potting, Encapsulating, and Lead Forming, Application Note 27703.1;
• Soldering of Through-Hole Hall-Sensor Dervices, Application Note 27703; and
• Soldering of Surface-Mount Hall-Sensor Devices, Application Note 27703.2. All are provided in Allegro Electronic Data Book, AMS-702. or at www.allegromicro.com Allegro

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH www.allegromicro.com 9 A3195ELT AND A3195LLT Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) NOTE — Exact body and lead configuration at vendor’s option within limits shown. Dwg. MA-009-3A in 1 23 0.072 0.064 0.167 0.155 0.059 BSC 0.0189 0.01420.047 0.035 0.102 0.090 0.063 0.055 0.0173 0.0138 0.090 0.084 0.0221 0.0173 0.118 BSC 0.181 0.173 Dwg. MA-009-3A mm 1 23 4.60 4.40 1.83 1.62 4.25 3.94 1.50 BSC 0.48 0.361.20 0.89 2.60 2.29 1.60 1.40 0.44 0.35 2.29 2.13 0.56 0.44 3.00 BSC

PROTECTED, HIGH-TEMP ., ACTIVE PULL-DOWN HALL-EFFECT LATCH Worcester, Massachusetts 01615-0036 (508) 853-500010 A3195EU AND A3195LU Dimensions in Inches Dimensions in Millimeters (controlling dimensions) (for reference only) Dwg. MH-003E mm 1.60 1.50 0.46 0.44 0.35 0.48 0.36 1.27 1 2 3 2.54 45° SEE NOTE 4.65 4.52 4.60 4.47 15.24 14.23 2.18 MAX Dwg. MH-003E in 0.063 0.059 0.018 0.0173 0.0138 0.0189 0.0142 0.050 1 2 3 0.100 45° SEE NOTE 0.183 0.178 0.181 0.176 0.600 0.560 0.086 MAX 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.