Data Sheet 27621.4B 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION X These Hall-effect switches are monolithic integrated circuits with tighter magnetic specifications, designed to operate continuously over extended temperatures to +150°C, and are more stable with both temperature and supply voltage changes. The unipolar switching characteristic makes these devices ideal for use with a simple bar or rod magnet. The three basic devices (3121, 3122, and 3123) are identical except for magnetic switch points. CC 2 3 OUTPUT SUPPLY 1 GROUND V Dwg. PH-003A Each device includes a voltage regulator for operation with supply voltages of 4.5 voltas to 24 volts, reverse battery protection diode, quadratic Hall-voltage generator, temperature compensation circuitry, small-signal amplifier, Schmitt trigger, and an open-collector output to sink up to 25 mA. With suitable output pull up, they can be used with bipolar or CMOS logic circuits. The 3121 is an improved replacement for the 3113 and 3119. The first character of the part number suffix determines the device operating temperature range. Suffix ‘E–’ is for the automotive and industrial temperature range of -40°C to +85°C. Suffix ‘L–’ is for the automotive and military temperature range of -40°C to +150°C. Three package styles provide a magnetically optimized package for most applications. Suffix ‘–LT’ is a miniature SOT-89/TO-243AA transistor package for surface-mount applications; suffix ‘–U’ is a three-lead plastic mini-SIP while suffix ‘–UA’ is a three-lead ultra-mini-SIP. Pinning is shown viewed from branded side. ABSOLUTE MAXIMUM RATINGS at TA = +25°C Supply Voltage, VCC ........................... 30 V Reverse Battery Voltage, VRCC ........ -30 V FEATURES and BENEFITS ■ Superior Temp. Stability for Automotive or Industrial Applications ■ 4.5 V to 24 V Operation … Needs Only An Unregulated Supply Magnetic Flux Density, B ....... Unlimited ■ Open-Collector 25 mA Output … Compatible with Digital Logic Output OFF Voltage, VOUT ................ 28 V ■ Reverse Battery Protection Reverse Output Voltage, VOUT ........ -0.5 V ■ Activate with Small, Commercially Available Permanent Magnets Continuous Output Current, IOUT ... 25 mA ■ Solid-State Reliability … No Moving Parts Operating Temperature Range, TA Suffix ‘E–’ ................. -40°C to +85°C Suffix ‘L–’ ............... -40°C to +150°C Storage Temperature Range, TS .............................. -65°C to +170°C ■ Small Size ■ Resistant to Physical Stress Always order by complete part number, e.g., A3121EU . 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION ELECTRICAL CHARACTERISTICS over operating temperature range, at VCC = 12 V. Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Supply Voltage VCC Operating 4.5 — 24 V VOUT(SAT) IOUT = 20 mA, B > BOP — 140 400 mV Output Leakage Current IOFF VOUT = 24 V, B < BRP — <1.0 10 µA Supply Current ICC B < BRP (Output OFF) — 4.6 9.0 mA Output Rise Time tr RL = 820 Ω, CL = 20 pF — 0.04 2.0 µs Output Fall Time tf RL = 820 Ω, CL = 20 pF — 0.18 2.0 µs Output Saturation Voltage MAGNETIC CHARACTERISTICS in gauss over operating supply voltage range. Part Numbers* A3121 Characteristic BOP at TA = 25°C over operating temp. range BRP at TA = 25°C over operating temp. range Bhys at TA = 25°C over operating temp. range A3122 A3123 Min. Typ. Max. Min. Typ. Max. Min. Typ. Max 250 350 450 280 340 400 250 345 440 220 350 500 260 340 430 230 345 470 125 245 380 140 235 330 180 240 300 80 245 410 120 235 360 160 240 330 70 105 140 70 105 140 70 105 140 60 105 150 70 105 140 70 105 140 NOTES: Typical values are at TA = +25°C and VCC = 12 V. BOP = operate point (output turns ON); BRP = release point (output turns OFF); Bhys = hysteresis (BOP - BRP). *Complete part number includes a suffix to identify operating temperature range (E- or L-) and package type ( -LT, -U, or -UA). FUNCTIONAL BLOCK DIAGRAM 1 VCC REG. X 3 OUTPUT 2 GROUND Dwg. FH-005-2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1992, 1999, Allegro MicroSystems, Inc. 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION TYPICAL OPERATING CHARACTERISTICS SWITCH POINTS OUTPUT SATURATION VOLTAGE 0 400 I OUT = 20 mA OPERATE POINT V CC = 4.5–24 V SWITCH POINT IN GAUSS 300 0 RELEASE POINT 200 0 V CC = 12 V 100 0 -50 0 -50 -25 0 25 50 100 75 125 150 -25 0 25 50 100 75 125 Dwg. GH-040 Dwg. GH-038 SUPPLY CURRENT SUPPLY CURRENT 7.0 10 6.0 8.0 SUPPLY CURRENT IN mA SUPPLY CURRENT IN mA VCC = 12 V B ≥ B OP 5.0 -25 0 25 50 75 100 B ≥ B OP 6.0 B ≤ B RP 4.0 T A = +25°C 2.0 B ≤ B RP 4.0 -50 150 AMBIENT TEMPERATURE IN °C AMBIENT TEMPERATURE IN °C 125 150 AMBIENT TEMPERATURE IN °C 0 0 5 10 15 20 25 SUPPLY VOLTAGE IN VOLTS Dwg. GH-039 * Complete part number includes a suffix denoting operating temperature range (E- or L-) and package type ( -LT, -U, or -UA). Dwg. GH-041 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION OPERATION SENSOR LOCATIONS (±0.005" [0.13 mm] die placement) Suffix “LT” ACTIVE AREA DEPTH 0.030" 0.76 mm NOM 0.089" 2.26 mm 0.043" 1.09 mm The output of these devices (pin 3) switches low when the magnetic field at the Hall sensor exceeds the operate point threshold (BOP). At this point, the output voltage is VOUT(SAT). When the magnetic field is reduced to below the release point threshold (BRP), the device output goes high. The difference in the magnetic operate and release points is called the hysteresis (Bhys) of the device. This built-in hysteresis allows clean switching of the output even in the presence of external mechanical vibration and electrical noise. APPLICATIONS INFORMATION A 1 2 Hall effect applications information is available in the “Hall-Effect IC Applications Guide”, which can be found in the latest issue of Allegro MicroSystems Data Book AMS-702. 3 Dwg. MH-008-2C Suffix “U” ACTIVE AREA DEPTH 0.016" 0.41 mm NOM CHANGE IN OPERATE POINT 0.091" 2.31 mm 0.070" 1.78 mm A BRANDED SURFACE 1 2 3 Dwg. MH-002-2B Suffix “UA” ACTIVE AREA DEPTH 0.019" 0.48 mm NOM CHANGE IN OPERATE POINT IN GAUSS 20 15 T A = +25°C 10 5.0 0 -5.0 0.082" 2.07 mm 0 5 10 15 20 25 SUPPLY VOLTAGE IN VOLTS Dwg. GH-042 0.055" 1.38 mm A BRANDED SURFACE 1 2 3 Dwg. MH-011-2C 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION PACKAGE DESIGNATOR ‘LT’ Dimensions in Inches (for reference only) 0.173 0.181 0.064 0.072 0.155 0.167 1 2 0.055 0.063 3 0.090 0.102 0.014 0.017 0.084 0.090 0.014 0.019 0.017 0.022 0.035 0.047 0.059 BSC 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 1 2 1.40 1.60 3 2.29 2.60 0.35 0.44 2.13 2.29 0.36 0.48 0.89 1.20 0.44 0.56 1.50 BSC 3.00 BSC NOTE: Exact body and lead configuration at vendor's option within limits shown. Dwg. MA-009-3 mm 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION PACKAGE DESIGNATOR ‘U’ Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) 4.65 4.52 0.183 0.178 1.60 1.50 0.063 0.059 4.60 4.47 0.181 0.176 45° 45° 0.086 1 2 0.018 3 2.18 1 2 0.46 3 MAX MAX 0.600 0.560 15.24 14.23 0.015 0.38 0.41 0.016 SEE NOTE SEE NOTE 1.27 0.050 2.54 0.100 Dwg. MH-003D in Devices in the ‘U’ package are NOT RECOMMENDED FOR NEW DESIGN 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. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Dwg. MH-003D mm 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION PACKAGE DESIGNATOR ‘UA’ Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) 0.164 0.159 4.17 4.04 0.062 0.058 45° 1.57 1.47 45° 0.122 0.117 3.10 2.97 45° 0.085 1 2 3 45° 0.031 2.16 MAX 1 2 3 0.79 MAX 0.640 0.600 16.26 15.24 0.015 SEE NOTE SEE NOTE 0.016 0.050 BSC 0.38 0.41 1.27 Dwg. MH-014D in 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. BSC Dwg. MH-014D mm 3121, 3122, AND 3123 HALL-EFFECT SWITCHES FOR HIGH-TEMPERATURE OPERATION 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