A1185 ALLEGRO | Alldatasheet
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A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000
115 Northeast Cutoff, Box 15036
www.allegromicro.com Allegro MicroSystems, Inc. AB SO LUTE MAX I MUM RAT INGS Operating Temperature Ambient, T On-chip protection y Supply transient protection y Reverse-battery protection y On-board voltage regulator y 3.5 V to 24 V operation Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall-Effect Switches Package LH, 3-pin SOT Features and Benefits 1. VCC 2. No connection 3. GND NC 1 2 1 2 3 1. VCC 2. GND 3. GND Package UA, 3-pin SIP Chopper stabilization y Low switchpoint drift over operating temperature range y Low stress sensitivity Field-programmable for optimized switchpoints The A1185 and A1186 are ultrasensitive, two-wire, unipolar Hall effect switches. The operate point, BOP, can be field-programmed, after final packaging of the sen- sor and placement into the application. This advanced feature allows the optimiza- tion of the sensor switching performance, by effectively accounting for variations caused by mounting tolerances for the device and the target magnet. This family of devices are produced on the Allegro MicroSystems new DABIC5 BiCMOS wafer fabrication process, which implements a patented, high-frequency, chopper-stabilization technique that achieves magnetic stability and eliminates the offsets that are inherent in single-element devices exposed to harsh applica- tion environments. Commonly found in a number of automotive applications, the A1185 and A1186 devices are utilized to sense: seat track position, seat belt buckle presence, hood/trunk latching, and shift selector position. Two-wire unipolar switches are particularly advantageous in price-sensitive appli- cations, because they require one less wire than the more traditional open-collec- tor output switches. Additionally, the system designer gains inherent diagnostics because output current normally flows in either of two narrowly-specified ranges. This provides distinct current ranges for I OUT(H) and IOUT(L). Any output current level outside of these two ranges is a fault condition. Other features of the A1185 and A1186 devices include on-chip transient protec- tion and a Zener clamp on the power supply to protect against overvoltage condi- tions on the supply line. The output current of the A1186 switches HIGH in the presence of a south polarity magnetic field of sufficient strength; and switches LOW otherwise, including when there is no significant magnetic field present. The A1185 has an inverted output current level: switching LOW in the presence of a south polarity magnetic field of sufficient strength, and HIGH otherwise. Both devices are offered in two package styles: LH, a SOT-23W miniature low- profile package for surface-mount applications, and UA, a three-lead ultramini Single Inline Package (SIP) for through-hole mounting. Each package is available in a lead (Pb) free version (suffix, –T) with 100% matte tin plated leadframe. Factory-programmed versions are also available. Refer to: A1145 and A1146.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 Product Selection Guide Functional Block Diagram Amp Regulator Program/Lock Low-Pass Filter GND VCC GND Programming Logic Package UA Only Offset Adjust Clock/Logic Dynamic Offset Cancellation Sample and Hold To all subcircuits 0.01 uF Part Number Pb- free Packinga Mounting Ambient, TA (°C) Output South (+) Fieldb Supply Current at Low Output, ICC(L) (mA) A1185ELHLT – 7-in. reel, 3000 pieces/reel Surface mount –40 to 85 Low 5 to 6.9 A1185ELHLT-T Yes A1185EUA – Bulk, 500 pieces/bag 4-pin SIP through hole A1185EUA-T Yes A1185LLHLT – 7-in. reel, 3000 pieces/reel Surface mount –40 to 150 A1185LLHLT-T Yes A1185LUA – Bulk, 500 pieces/bag 4-pin SIP through hole A1185LUA-T Yes A1186ELHLT – 7-in. reel, 3000 pieces/reel Surface mount –40 to 85 High A1186ELHLT-T Yes A1186EUA – Bulk, 500 pieces/bag 4-pin SIP through hole A1186EUA-T Yes A1186LLHLT – 7-in. reel, 3000 pieces/reel Surface mount –40 to 150 A1186LLHLT-T Yes A1186LUA – Bulk, 500 pieces/bag 4-pin SIP through hole A1186LUA-T Yes aContact Allegro for additional packing options. bSouth (+) magnetic fields must be of sufficient strength.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 ELECTRICAL CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units Supply Voltage1 VCC Device powered on 3.5 – 24 V Supply Current2 ICC(L) B >BOP for A1185; B <BRP for A1186 5 – 6.9 mA ICC(H) B >BOP for A1186; B <BRP for A1185 12 – 17 mA Supply Zener Clamp Voltage V ZSupply ICC = ICC(L)(Max) + 3 mA; TA = 25°C 28 – 40 V Supply Zener Clamp Current3 IZSupply VSupply = 28 V – – 9.9 mA Reverse Supply Current I RCC VRCC = –18 V – – 1.6 mA Output Slew Rate4 di/dt No bypass capacitor; capacitance of the oscilloscope performing the measurement = 20 pF – 36 – mA/ μs Chopping Frequency f C – 200 – kHz Power-On Time5 ton After factory trimming; with and without bypass capacitor (CBYP = 0.01 μF) –– 2 5 μs Power-On State6,7 POS t on ≤ ton(max); VCC slew rate > 25 mV/μs – HIGH – – 1VCC represents the generated voltage between the VCC pin and the GND pin. 2Relative values of B use the algebraic convention, where positive values indicate south magnetic polarity, and negative values indicate north magnetic polarity; therefore greater B values indicate a stronger south polarity field (or a weaker north polarity field, if present). 3IZSUPPLY(max) = ICCL(max) + 3 mA. 4Measured without bypass capacitor between VCC and GND. Use of a bypass capacitor results in slower current change. 5Measured with and without bypass capacitor of 0.01 μF. Adding a larger bypass capacitor causes longer Power-On Time. 6POS is defined as true only with a V CC slew rate of 25 mV / μs or greater. Operation with a V CC slew rate less than 25 mV / μs can permanently harm device performance. 7POS is undefined for t > ton or BRP < B < BOP . MAGNETIC CHARACTERISTICS1 over the operating voltage and temperature ranges, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ. Max. Units Programmable Operate Point Range B OPrange ICC = ICC(L) for A1185 ICC = ICC(H) for A1186 10 – 60 G Initial Operate Point Range B OPinit VCC = 12 V – –10 10 G Switchpoint Step Size2 BRES VCC = 5 V, TA = 25°C 2 4 6 G Number of Programming Bits – Switchpoint setting – 5 – Bit Programming locking – 1 – Bit Temperature Drift of BOP ΔBOP – – ±20 G Hysteresis B HYS BHYS = BOP – BRP 51 5 3 0G 1Relative values of B use the algebraic convention, where positive values indicate south magnetic polarity, and negative values indicate north magnetic polarity; therefore greater B values indicate a stronger south polarity field (or a weaker north polarity field, if present). 2The range of values specified for BRES is a maximum, derived from the cumulative programming bit errors.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 Characteristic Data -50 0 50 100 150 200 01234 6 5 -50 0 50 100 150 200 -50 0 50 100 150 200 –10 –20 ICC(L) versus Ambient Temperature at Various Levels of VCC (A1185 and A1186) ICC(H) versus Ambient Temperature at Various Levels of VCC (A1185 and A1186) Ambient Temperature, TA (°C) Ambient Temperature, T A (°C) ICC(H) (mA) ICC(L) (mA) BOP Set by Specific Programming Bit VCC =1 2V T A = 25°C (A1185 and A1186) Bit Number BOP (G) VCC (V) 3.5 12.0 24.0 VCC (V) 3.5 12.0 24.0 Hysteresis versus Ambient Temperature at Various Levels of VCC (A1185 and A1186) Ambient Temperature, TA (°C) BHYS (G) VCC (V) 3.5 12.0 24.0 Device Qualification Program EMC (Electromagnetic Compatibility) Requirements Test Name Reference Specification ESD – Human Body Model AEC-Q100-002 ESD – Machine Model AEC-Q100-003 Conducted Transients ISO 7637-1 Direct RF Injection ISO 11452-7 Bulk Current Injection ISO 11452-4 TEM Cell ISO 11452-3 Contact Allegro for information. Contact your local representative for EMC results.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 THERMAL CHARACTERISTICS may require derating at maximum conditions, see application information Characteristic Symbol Test Conditions* Value Units Package Thermal Resistance RθJA Package LH, 1-layer PCB with copper limited to solder pads 228 ºC/W Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias 110 ºC/W Package UA, 1-layer PCB with copper limited to solder pads 165 ºC/W *Additional thermal information available on Allegro Web site. 20 40 60 80 100 120 140 160 180 Temperature (ºC) Maximum Allowable VCC (V) Power Derating Curve (RθJA = 228 ºC/W) 1-layer PCB, Package LH (RθJA = 110 ºC/W) 2-layer PCB, Package LH (RθJA = 165 ºC/W) 1-layer PCB, Package UA VCC(min) VCC(max) 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 20 40 60 80 100 120 140 160 180 Temperature (°C) Power Dissipation, PD (mW) Power Dissipation versus Ambient Temperature θJA = 165 ºC/ 1-laye r PCB, P ackag e UA θJA = 228º C/W) 1-layerP CB, Package LH θJA = 110 ºC/W) 2-layer PCB, Package LH
field at the Hall sensor exceeds the operate point threshold, BOP. in comparison to the A1185 (see figure 1). Figure 1. Alternative switching behaviors are available in the A118x device family. On the horizontal axis, the B+ direction indicates case of increasing north polarity).
Figure 2. Chopper stabilization circuit (dynamic quadrature offset cancellation) the signal passes while the modulated dc offset is suppressed. high-density logic integration and sample-and-hold circuits.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186
Application Information
For additional general application information, visit the Allegro Web site at www. allegromicro.com. GND A118x VCC 0.01 uF A B BGND ECU Package UA OnlyA B Maximum separation 5 mm RSENSE CBYP Figure 3. Typical application circuit BYP, installed in parallel with the A118x. tion with CBYP, creates a filter for EMI pulses. would be incorrect switchpoints.
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 Power Derating The device must be operated below the maximum junction temperature of the device, TJ(max). Under certain combinations of peak conditions, reliable operation may require derating sup- plied power or improving the heat dissipation properties of the application. This section presents a procedure for correlating factors affecting operating T J. (Thermal data is also available on the Allegro MicroSystems Web site.) The Package Thermal Resistance, RθJA, is a figure of merit sum- marizing the ability of the application and the device to dissipate heat from the junction (die), through all paths to the ambient air. Its primary component is the Effective Thermal Conductivity, K, of the printed circuit board, including adjacent devices and traces. Radiation from the die through the device case, R θJC, is relatively small component of RθJA. Ambient air temperature, TA, and air motion are significant external factors, damped by overmolding. The effect of varying power levels (Power Dissipation, PD), can be estimated. The following formulas represent the fundamental relationships used to estimate T J, at PD. PD = VIN × IIN (1) Δ T = PD × RθJA (2) T J = TA + ΔT (3) For example, given common conditions such as: TA= 25°C, VCC = 12 V, ICC = 4 mA, and RθJA = 140 °C/W, then: P D = VCC × ICC = 12 V × 4 mA = 48 mW Δ T = PD × RθJA = 48 mW × 140 °C/W = 7°C T J = TA + ΔT = 25°C + 7°C = 32°C A worst-case estimate, PD(max), represents the maximum allow- able power level (VCC(max), ICC(max)), without exceeding TJ(max), at a selected RθJA and TA. Example: Reliability for VCC at TA = 150°C, package UA, using minimum-K PCB. Observe the worst-case ratings for the device, specifically: RθJA = 165°C/W, TJ(max) = 165°C, VCC(max) = 24 V , and ICC(max) = 17 mA. Calculate the maximum allowable power level, PD(max). First, invert equation 3: ΔTmax = TJ(max) – TA = 165 °C – 150 °C = 15 °C This provides the allowable increase to TJ resulting from internal power dissipation. Then, invert equation 2: PD(max) = ΔTmax ÷ RθJA = 15°C ÷ 165 °C/W = 91 mW Finally, invert equation 1 with respect to voltage: VCC(est) = PD(max) ÷ ICC(max) = 91 mW ÷ 17 mA = 5 V The result indicates that, at TA, the application and device can dissipate adequate amounts of heat at voltages ≤VCC(est). Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reli- able operation between VCC(est) and VCC(max) requires enhanced RθJA. If VCC(est) ≥ VCC(max), then operation between VCC(est) and VCC(max) is reliable under these conditions.
1Programming voltages are measured at the VCC pin. provide the current necessary to blow the fuse. Figure 4. Pulse amplitudes and durations software is available free of charge. hysteresis, BHYS , is fixed. physically represented by 5 bitfields in the onboard registers. CC to fall to zero (which clears the registers). pulse is sent at the end of the pulse sequence.
Figure 6. Pulse sequence to permanently encode calibration value 5 (101 binary, or bitfield address 3 and bitfield address 1).
- A bitfield address sequence.
- When permanently setting the bitfield, a long V
- When permanently setting the bitfield, the level of VCC must
preparing to set additional bitfields. period, enough to blow the corresponding bitfield-level fuse. Figure 5. Pulse sequence to provisionally try calibration value 5.
Figure 8. Pulse sequence to select addresses Figure 9. Pulse sequence to encode lock bit setting the other bitfields, as shown in figure 9. Figure 7. Addressing mode enable pulse sequence
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 Package LH, 3-Pin (SOT-23W) 2.40 BSC .094 1.00 BSC .039 0.70 BSC .028 3.10 2.90 .122 .114 2.10 1.85 .083 .073 3.00 2.70 .118 .106 0.55 REF .022 1.49 NOM .059 0.28 NOM .011 0.96 NOM .038 0.95 BSC .037 0.95 BSC .037 0.25 MIN .010 0.15 0.00 .006 .000 1.13 0.87 .045 .034 0.20 0.13 .008 .005 0.50 .020 .0120.30 0.25 BSC .010 Gauge Plane Seating Plane Dimensions in millimeters U.S. Customary dimensions (in.) in brackets, for reference only A Hall element B Active Area Depth 0.28 [.011] C C Fits SC–59A Solder Pad Layout A Package UA, 3-Pin B .164 .159 4.17 4.04 .122 .117 3.10 2.97 .062 .058 1.57 1.47 .017 .014 0.44 0.35 .019 .014 0.48 0.36 .640 .600 16.26 15.24 .085 MAX 2.16 .050 BSC 1.27 .031 REF 0.79 .0195 NOM 0.50 .0805 NOM 2.04 1.44.0565 NOM 45° BSC 45° BSC Dimensions in inches Metric dimensions (mm) in brackets, for reference only 231 A A B Dambar removal protrusion Hall element
A1185-DS, Rev. 1 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com Allegro MicroSystems, Inc. Ultrasensitive Two-Wire Field-Programmable Chopper-Stabilized Unipolar Hall Effect Switches A1185 and A1186 The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 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 de par tures from the detail spec i fi ca tions as may be required to permit improvements in the per for mance, 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 compo- nents in life-support devices or sys tems without express written approval. The in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon - si bil i ty for its use; nor for any in fringe ment of patents or other rights of third parties which may result from its use. Copyright © 2005 Allegro MicroSystems, Inc.