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1 357 A 358 ata heet LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMPERATURE OPERATIO V CC 1 UPPLY X 2 GROU Pinning is shown viewed from branded side. ABOLUTE MAXIMUM RATIG upply Voltage, V CC V Output Voltage, V O V Output ink Current, I O ma Magnetic Flux ensity, B.... Unlimited Package Power issipation, P ee Graph Operating Temperature Range, T A uffix C to +85 C uffix E C to +85 C uffix L C to +15 C torage Temperature Range, T C to +17 C 3 OUTPUT wg. PH-6 The A357 and A358 are sensitive, temperature-stable linear Hall-effect sensor ICs. Ratiometric, linear Hall-effect circuits provide a voltage output that is proportional to the applied magnetic field and have a quiescent output voltage that is approximately 5% of the supply voltage. These devices are ideal for use in linear and rotary position sensing systems in the harsh environments of automotive and industrial applications over extended temperatures to -4 C and +15 C. The two devices are similar except for temperature stability over the operating temperature range. ee the Magnetic Characteristics table for complete, individual device parametrics. Each monolithic circuit integrates a quadratic Hall element, improved temperature compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, and a rail-to-rail low-impedance output stage. Many problems normally associated with low-level analog signals are minimized by having the Hall element and amplifier in a single chip. Output precision is obtained by internal gain and offset trim adjustments during the manufacturing process. The first character of the part number suffix determines the device operating temperature range: suffix is for -2 C to +85 C, suffix E is for -4 C to +85 C, and suffix L is for -4 C to +15 C. These devices are supplied in a 3-pin ultra-mini-ip UA package. FEATURE Output Voltage Proportional to Applied Magnetic Field Ratiometric Rail-to-Rail Output Improved ensitivity uperior Temperature tability 4.5 V to 5.5 V Operation ICOTIUE PROUCT mall Package ize olid-tate Reliability FOR REFERECE OLY. Always order by complete part number, e.g., A357EUA.

2 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO FUCTIOAL BLOCK IAGRAM 7 1 X V CC 3 2 OUTPUT GROU wg. FH-11 ALLOWABLE PACKAGE POWER IIPATIO in MILLIWATT "U" PACKAGE RθJA = 183 C/W "UA" PACKAGE RθJA = 26 C/W AMBIET TEMPERATURE in C 16 wg. GH-46A ELECTRICAL CHARACTERITIC over operating temperature range, at V CC = 5 V (unless otherwise noted). Characteristic ymbol Test Conditions Min. Typ. Limits upply Voltage V CC Operating V upply Current I CC B =, V CC = 5.5 V, I O = 1 ma Quiescent V OQ B =, I O = 1 ma, T A = 25 C V Voltage Output B =, I O = 1 ma V Output Voltage V OH B = +X *, I O = 1 ma V Bandwidth (-3 db) Max. V OL B = -X *, I O = -1 ma.2.5 V BW Output Resistance r O Ω Wide-Band e o B =, BW = 1 Hz to 1 khz, 125 µv Output oise TA egative current is defined as coming out of (sourcing) the output. * This test requires positive and negative fields sufficient to swing the output driver between fully OFF and saturated (O), respectively. It is OT intended to indicate a range of linear operation. 2 Units khz 115 ortheast Cutoff, Box 1536 Worcester, Massachusetts (58) Copyright 1994, 21, Allegro Microystems, Inc.

3 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO MAGETIC CHARACTERITIC over operating temperature range, at V CC = 5 V, I O = 1 ma (unless otherwise noted). Part umbers A357LUA A357EUA A358UA Characteristic * Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Units Operating Temp. Range, T A C ensitivity at T A = 25 C mv/g over Oper. Temp. Range mv/g ens ( T) at T A = Max % at T A = Min % V OQ( T) ±35 ±35 ±5 G Ratiometry, V OQ( V) % Ratiometry, ens ( V) % Positive Linearity, Lin % egative Linearity, Lin % ymmetry 1 Magnetic flux density is measured at most sensitive area of device located.18" (.46 mm) below the branded face of the UA package. * ee Characteristics efinitions for test conditions. The nominal sensitivity temperature stability is designed to compensate for the temperature coefficient of samarium-cobalt magnets (-.2%/ C). This calculation (formula 1, next page) yields the device s equivalent accuracy, over the operating temperature range, in gauss. 1 1 %

4 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO CHARACTERITIC EFIITIO Quiescent Voltage Output. In the quiescent state (no magnetic field), the output is ideally equal to one-half of the supply voltage over the operating voltage and temperature range (V OQ V CC /2). ue to internal component tolerances and thermal considerations, there is a tolerance on the quiescent voltage output and on the quiescent voltage output as a function of supply voltage and ambient temperature. For purposes of specification, the quiescent voltage output as a function of temperature is defined as Ratiometry. The A357 and A358 feature a ratiometric output. The quiescent voltage output and sensitivity are proportional to the supply voltage (ratiometric). The per cent ratiometric change in the quiescent voltage output is defined as V OQ( V) = V OQ(VCC) / V OQ(5V) x 1% (4) V CC / 5 V V OQ( T) = V OQ(TA) V OQ(25 C) ens (25 C) (1) and the per cent ratiometric change in sensitivity is defined as This calculation yields the device s equivalent accuracy, over the operating temperature range, in gauss. ensitivity. The presence of a south-pole magnetic field perpendicular to the package face (the branded surface) will increase the output voltage from its quiescent value toward the supply voltage rail by an amount proportional to the magnetic field applied. Conversely, the application of a north pole will decrease the output voltage from its quiescent value. This proportionality is specified as the sensitivity of the device and is defined as ens ( V) = ens (VCC) / ens (5V) x 1% (5) V CC / 5 V Linearity and ymmetry. The on-chip output stage is designed to provide a linear output to within 5 mv of either rail with a supply voltage of 5 V. This is equivalent to approximately ±8 gauss of ambient field. Although application of stronger magnetic fields will not damage these devices, it will force the output into a non-linear region. Linearity in per cent is measured and defined as ens = V O(5G) V O(-5G) 1 G (2) Lin+ = V O(5G) V OQ x 1% (6) 2 (V O(25G) V OQ ) The stability of sensitivity as a function of temperature is defined as ens ( T) = ens (TA) ens (25 C) x 1% (3) ens (25 C) and output symmetry as Lin = V O(-5G) V OQ x 1% (7) 2 (V O(-25G) V OQ ) ym = V O(5G) V OQ x 1% (8) V OQ V O(-5G) 115 ortheast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

5 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO APPLICATIO IFORMATIO ELEMET LOCATIO Calibrated linear Hall devices, which can be used to determine the actual flux density presented to the element in a particular application, are available. ACTIVE AREA EPTH.195".5 mm OM.82" 2.7 mm For safe, reliable operation, the output should not be pulled above the supply voltage or pulled below the device ground. For optimum performance, a 1 pf capacitor between the output and ground should be added. BRAE URFACE A " 1.4 mm The nominal sensitivity is factory set to compensate for the temperature coefficient of samarium-cobalt magnets (-.2%/ C). The ratiometric feature is especially valuable when these devices are used with an analog-to-digital converter. A/ converters typically derive their LB step size by ratioing off a reference voltage line. If the reference voltage varies, the LB will vary proportionally. This is a major error source in many sensing systems. The A357/8 can eliminate this source of error by their ratiometric operation. Because their gain and offsets are proportional to the supply voltage, if they are powered from the A/ reference voltage, the device output voltage will track changes in the LB value. Hall-effect applications information is available in the application note Linear Hall-Effect ensor ICs (A 2772), which can be found in the latest issue of Allegro Electronic ata Book, AM-72, or at wg. MH-11-6B TYPICAL CURRET-EIG APPLICATIO B x 6.9 G/A wg. AH-5A

6 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO TYPICAL POITIO-EIG APPLICATIO (Alnico 8, dimensions in inches) + VCC + VCC.21 ELEMET EPTH BELOW PACKAGE FACE RELATIVE MAGETIC FLUX EITY RELATIVE OUTPUT VOLTAGE RELATIVE MAGETIC FLUX EITY.19 VOQ RELATIVE OUTPUT VOLTAGE VOQ RELATIVE ITACE (TOTAL EFFECTIVE AIR GAP) wg. GH G RELATIVE ITACE wg. GH-49 + VCC + VCC.19 EFFECTIVE AIR GAP EFFECTIVE AIR GAP =.5 RELATIVE MAGETIC FLUX EITY VOQ RELATIVE OUTPUT VOLTAGE RELATIVE MAGETIC FLUX EITY EFFECTIVE AIR GAP =.75 EFFECTIVE AIR GAP = RELATIVE OUTPUT VOLTAGE RELATIVE ITACE.2 G.4 wg. GH-48 VOQ RELATIVE ITACE wg. GH ortheast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

7 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO imensions in Inches (controlling dimensions) imensions in Millimeters (for reference only) MAX MAX EE OTE EE OTE BC wg. MH-14E in 1.27 BC wg. MH-14E mm OTE: 1. Tolerances on package height and width represent allowable mold offsets imensions 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.35" (.89 mm). 5. Where no tolerance is specified, dimension is nominal.

8 357 A 358 LIEAR HALL-EFFECT EOR IC FOR HIGH-TEMP. OPERATIO The products described herein are manufactured under one or more of the following U.. patents: 5,45,92; 5,264,783; 5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,65,719; 5,686,894; 5,694,38; 5,729,13; 5,917,32; and other patents pending. Allegro Microystems, 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 Microystems, 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 ortheast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

RATIOMETRIC, LINEAR HALL-EFFECT SENSORS FOR HIGH-TEMPERATURE OPERATION

356, 357, 358 356, 357, 358 V CC X The 356, 357, and 358 comprise a family of sensitive, temperature-stable linear Hall-effect sensors. Ratiometric, linear Hall-effect sensors provide a voltage output