A1160 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics Description Features and Benefits •AEC-Q100 automotive qualified •Unipolar switchpoints • Externally enabled diagnostics feature • Diagnostics feature exercises the entire magnetic and electrical signal path within the IC • Resistant to physical stress • Superior temperature stability through advanced chopper stabilization techniques • Output short-circuit protection • Internal regulator enables operation from unregulated supplies • Reverse-battery protection • Solid-state reliability • Small surface-mount package Package: 5-pin SOT23W (suffix LH) The A1160 is a unipolar, Hall-effect switch with an externally enabled diagnostic function. In normal operating mode, the A1160 functions as a standard, unipolar Hall-effect switch. The output transistor turns on (output signal switches low) in the presence of a sufficient magnetic field (>BOP(max)). Additionally, the output transistor of the A1160 switches off (output signal switches high) when the magnetic field is removed (< BRP(min)). The A1160 includes conductive coils in close proximity to the Hall element. When the diagnostic feature is enabled, these coils are energized. The energized coils generate an internal magnetic field that can be sensed by the Hall element. While in Diagnostic mode, the output of the A1160 provides a square wave output, which confirms the IC is properly sensing the internally generated magnetic field. The Diagnostic mode exercises the entire magnetic and electrical signal path internal to the IC, fully confirming functionality. Therefore, use of the A1160 either eliminates the need for redundant sensors in safety critical applications or increases robustness in safety critical applications that require redundant sensors (drive-by-wire systems and so forth). The A1160 Hall-effect sensor IC is extremely temperaturestable and stress-resistant, especially suited for operation Approximate footprint Continued on the next page… Functional Block Diagram Regulator VREG Hall Element VOUT To all subcircuits Dynamic Offset Cancellation VCC Signal Recovery Amplifier Control Threshold Normal Current Limit Diagnostic DIAG System Diagnostics GND A1160-DS, Rev. 1 A1160 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics Description (continued) at temperature ranges up to 150°C. Superior high-temperature performance is made possible through advanced dynamic offset cancellation techniques, which reduce the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. This device includes on a single silicon chip: a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a open-drain output able to sink up to 25 mA. An on-board regulator permits operation with supply voltages of 3.8 to 24 V. The A1160 is provided in a 5-pin SOT23W. The package is lead (Pb) free, with 100% matte-tin leadframe plating. Selection Guide Part Number Packing* A1160LLHLX-T 10,000 pieces per 13-in. reel *Contact Allegro™ for additional packing options. Absolute Maximum Ratings Characteristic Symbol Notes Rating Unit Forward Supply Voltage VCC 30 V Reverse Supply Voltage VRCC –18 V Forward Diagnostic Enable Voltage VDIAG 5.5 V Reverse Diagnostic Enable Voltage VRDIAG –0.5 V VOUT 30 V Output-Off Voltage Continuous Output Current IOUT 25 mA Reverse Output Current IROUT –50 mA Operating Ambient Temperature TA –40 to 150 ºC Maximum Junction Temperature TJ(max) 165 ºC Tstg –65 to 170 ºC Storage Temperature L temperature range Pin-Out Diagram 5 1 Terminal List Table Name Number Function DIAG 1, 3 VCC 2 Connects power supply to chip GND 4 Ground VOUT 5 Output from circuit Diagnostics enable (use either pin 1 or pin 3) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A1160 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics OPERATING CHARACTERISTICS: Valid across full operating voltage and ambient temperature ranges, unless otherwise specified Characteristic Symbol Test Conditions Min. Typ.1 Max. Unit2 Operating, TJ < 165°C 3.8 – 24 V VCC required for diagnostic functionality 3.8 – 24 V Electrical Characteristics Supply Voltage Output Leakage Current VCC IOUTOFF VOUT = 24 V, B < BRP – – 10 µA VOUT(SAT) IOUT = 20 mA, B > BOP – 185 400 mV IOM B > BOP 30 – 60 mA Power-On Time3 tPN VCC > 3.8 V , B < BRP(min) – 10 G , B > BOP(max) + 10 G – – 25 µs Chopping Frequency fC – 400 – kHz Output Rise Time3,4 tr RLOAD = 820 Ω, CL = 20 pF – 0.2 2 µs tf Output Saturation Voltage Output Current Limit Output Fall Time3,4 Supply Current5 Reverse Battery Current RLOAD = 820 Ω, CL = 20 pF – 0.1 2 µs ICC(ON) B < BRP , VCC = 12 V – – 5 mA ICC(OFF) B > BOP , VCC = 12 V – – 5 mA ICC(DIAG) VCC = 12 V, DIAG = 1 – 16 25 mA IRCC VRCC = –18 V – – –10 mA Supply Zener Clamp Voltage VZSUP ICC = 8 mA, TA = 25°C 30 – – V Output Zener Voltage VZOUT IOUT = 3 mA, TA = 25°C 28 – – V PWM Carrier Frequency fPWMout With Diagnostic mode enabled – 3 – kHz DFAIL DIAG = 1, device malfunction – ≈ 0 or ≈ 100 – % Diagnostic Characteristics Duty Cycle (Diagnostic Mode)6 DPASS DIAG = 1, device normal 40 50 60 % DIAG Pin Input Resistance RDIAG Internal pulldown resistor – 1 – MΩ DIAG Pin Input Low Voltage Threshold VIL Device in Normal mode – – 0.6 V DIAG Pin Input High Voltage Threshold VIH Device in Diagnostic mode 1.5 – 5.0 V Diagnostic Enable Time tD Time from VIH reaching 1.5 to 5.0 V until valid diagnostic output 1 – – ms Diagnostic Disable Time tDIS Time from DIAG pin release (high to low transition) until valid normal sensor IC output – – 25 µs Continued on the next page… Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 A1160 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics OPERATING CHARACTERISTICS (continued): Valid across full operating voltage and ambient temperature ranges, unless otherwise specified Characteristic Min. Typ.1 Max. Unit2 115 180 245 G 60 125 190 G 30 55 80 G BEXT(DIAG) 800 10,000 – G Operate Point Drift BOP(DRIFT) 30 – 420 G Release Point Drift BRP(DRIFT) 15 – 325 G Magnetic Symbol Test Conditions Characteristics7 Operate Point BOP Release Point BRP Hysteresis BHYS Maximum External Field in Diagnostic Mode8 BOP – BRP Drift Detection Threshold 1 Typical data is at TA = 25°C and VCC = 12 V and it is for design information only. G (gauss) = 0.1 mT (millitesla). 3 Power-On Time, Output Rise Time, and Output Fall Time are ensured through device characterization and not final test. 4 C = oscilloscope probe capacitance. L 5 In Diagnostic mode the supply current level is different from the Normal mode operation current level. This is important when determining the power derating for Diagnostic mode. 6 When the A1160 passes the diagnostic tests, it outputs a 50% duty cycle signal. Any other output indicates the test failed. Please see the Diagnostic Mode of Operation section for more information. 7 Magnetic flux density, B, is indicated as a negative value for north-polarity magnetic fields, and as a positive value for south-polarity magnetic fields. 8 800 G is the maximum test capability due to practical equipment limitations. Design simulations show that a 10,000 G external field will not adversely affect the A1160 in Diagnostic mode when a 1% sensitivity mismatch between the Hall elements in the IC is assumed. 21 Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 Thermal Characteristics: may require derating at maximum conditions; see application information Characteristic Symbol Test Conditions* RθJA Package Thermal Resistance On 4-layer PCB based on JEDEC standard Value Unit 124 ºC/W Maximum Allowable VCC (V) *Additional thermal information available on the Allegro website Power Derating Curve 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 VCC(max) Normal Mode (ICC(max) = 5 mA) Diagnostic Mode (ICC(max) = 25 mA) VCC(min) 20 40 60 80 100 120 140 160 180 Power Dissipation, PD (m W) Temperature (ºC) Power Dissipation versus Ambient Temperature 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 Diagnostic Mode (ICC(max) = 25 mA) Normal Mode (ICC(max) = 5 mA) 20 40 60 80 100 120 Temperature (°C) 140 160 180 Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 VOUT(SAT) vs. TA 400 VCC 3.8 V 12 V 24 V 350 300 250 200 150 100 50 0 -50 0 50 100 150 200 Output Saturation Voltage, VOUT(SAT) (V) Output Saturation Voltage, VOUT(SAT) (V) Characteristic Performance VOUT(SAT) vs. VCC 400 TA -40°C 25°C 150°C 350 300 250 200 150 100 50 0 0 5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 VCC 3.8 V 12 V 24 V 0 50 100 150 200 100 0 5 150 Supply Current, I CC(OFF) (mA) Supply Current, I CC(OFF) (mA) 200 30 TA -40°C 25°C 150°C 0 Supply Current, I CC(DIAG) (mA) Supply Current, I CC(DIAG) (mA) 25 5 10 15 20 25 30 ICC(DIAG) vs. VCC 20 15 10 VCC 3.8 V 12 V 24 V 5 0 100 20 Supply Voltage, VCC (V) 25 50 15 ICC(OFF) vs. VCC ICC(DIAG) vs. TA 0 10 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Ambient Temperature, TA (°C) -50 30 Supply Voltage, VCC (V) VCC 3.8 V 12 V 24 V 50 25 TA -40°C 25°C 150°C ICC(OFF) vs. TA 0 20 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 Ambient Temperature, TA (°C) 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -50 15 ICC(ON) vs. VCC Supply Current, I CC(ON) (mA) Supply Current, I CC(ON) (mA) ICC(ON) vs. TA -50 10 Supply Voltage, VCC (V) Ambient Temperature, TA (°C) 150 Ambient Temperature, TA (°C) 200 25 20 15 10 TA -40°C 25°C 150°C 5 0 0 5 10 15 20 25 30 Supply Voltage, VCC (V) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics fPWMout vs. TA fPWMout vs. VCC 6 VCC 3.8 V 12 V 24 V 5 4 3 2 1 0 -50 0 50 100 150 200 PWM Carrier Frequency, fPWMout (kHz) PWM Carrier Frequency, fPWMout (kHz) A1160 6 TA -40°C 25°C 150°C 5 4 3 2 1 0 0 5 Ambient Temperature, TA (°C) 60 58 56 54 52 50 48 46 44 42 40 VCC 3.8 V 12 V 24 V 0 50 100 15 20 25 30 DPASS vs. VCC Normal DIAG Duty Cycle, DPASS (%) Normal DIAG Duty Cycle, DPASS (%) DPASS vs. TA -50 10 Supply Voltage, VCC (V) 150 Ambient Temperature, TA (°C) 200 60 58 56 54 52 50 48 46 44 42 40 TA -40°C 25°C 150°C 0 5 10 15 20 25 30 Supply Voltage, VCC (V) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 BOP vs. VCC 250 Magnetic Operate Point, BOP (G) Magnetic Operate Point, BOP (G) BOP vs. TA VCC 3.8 V 12 V 24 V 230 210 190 170 150 130 110 -50 0 50 100 150 250 TA -40°C 25°C 150°C 230 210 190 170 150 130 110 200 0 5 Ambient Temperature, TA (°C) Magnetic Release Point, BRP (G) Magnetic Release Point, BRP (G) 195 VCC 3.8 V 12 V 24 V 175 155 135 115 95 75 55 0 50 100 150 155 135 115 TA -40°C 25°C 150°C 95 75 55 0 200 5 Magnetic Hysteresis, BHYS (G) Magnetic Hysteresis, BHYS (G) 10 15 20 25 30 Supply Voltage, VCC (V) VCC 3.8 V 12 V 24 V 100 30 BHYS vs. VCC 80 75 70 65 60 55 50 45 40 35 30 50 25 175 BHYS vs. TA 0 20 195 Ambient Temperature, TA (°C) -50 15 BRP vs. VCC BRP vs. TA -50 10 Supply Voltage, VCC (V) 150 Ambient Temperature, TA (°C) 200 80 75 70 65 60 55 50 45 40 35 30 TA -40°C 25°C 150°C 0 5 10 15 20 25 30 Supply Voltage, VCC (V) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 A1160 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics Functional Description Applications It is strongly recommended that an external bypass capacitor be connected between the supply and ground of the A1160 (in close proximity to the device) to reduce both external noise and noise generated by the chopper stabilization technique. As is shown in figure 2, a 0.1 μF capacitor is typical. Extensive applications information on magnets and Hall-effect sensor ICs is available on the Allegro website, including the following application notes: • Hall-Effect IC Applications Guide, AN27701 • Soldering Methods for Allegro’s Products – SMT and ThroughHole, AN26009 Switch to High VOUT(SAT) 0 BRP 0 BOP Powering-on the IC in the hysteresis range (applied magnetic lower than BOP but also higher than BRP ) results in output at the high state. The output will not switch until there is a valid transition beyond BOP or BRP . The correct output state is attained after the first excursion beyond BOP or BRP . VCC VOUT The difference in the magnetic operate and release points is the hysteresis, BHYS , of the IC. This built-in hysteresis allows clean switching of the output, including when in the presence of external mechanical vibration and electrical noise. V+ Switch to Low Operation The output of the A1160 switches low (turns on) when a magnetic field perpendicular to the Hall element exceeds the operate point threshold, BOP . After turn-on, the output is capable of sinking 25 mA and the output voltage is VOUT(SAT) . When the magnetic field is reduced below the release point, BRP , the output goes high (turns off). This is illustrated in figure 1. B+ BHYS Figure 1. Switching behavior of Hall effect switches. On the horizontal axis, the B+ direction indicates increasing south polarity magnetic field strength, and the B– direction indicates decreasing south polarity field strength (including the case of increasing north polarity). V+ CBYPASS From Controller RL VCC A1160 DIAG VOUT GND Output CL (Optional) Figure 2. Typical application circuit Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 Diagnostic Mode of Operation The Diagnostic mode is accessed by applying a voltage of VIH on the diagnostic enable pin (DIAG). The Diagnostic mode uses an internally generated magnetic signal to exercise the signal path. This signal is compared to two reference signals in the Schmitt trigger. If the diagnostic signal is between the two reference signals, the device is considered to be working within specification and a 50% PWM signal is set at the output pin (VOUT), as shown in figure 3. If the diagnostic signal is above the upper reference or below the lower reference, the output PWM is set at a fixed value that is either at nearly 0% or at nearly 100% duty cycle. The Diagnostic mode of operation not only detects catastrophic failures but also identifies drifts in the magnetic switchpoints. If BOP or BRP drift to values below or above the values stated in the Drift Detection Threshold section of the Operating Characteristics table, the output PWM is set at a fixed value that is either at nearly 0% or at nearly 100% duty cycle. DIAG DIAG t VOUT t VOUT Device OK Duty = 50% t Device Failure Duty 50% or Duty 50% t Figure 3. Diagnostics Functional Diagram. When the A1160 passes the diagnostic test, a 50% duty cycle signal is sent out (left panel). In the event of a failure, the output will be forced either high or low (right panel). Diagnostic mode is only active when the DIAG input pin is pulled high. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 10 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 Chopper Stabilization Technique When using Hall-effect technology, a limiting factor for switchpoint accuracy is the small signal voltage developed across the Hall element. This voltage is disproportionally small relative to the offset that can be produced at the output of the Hall IC. This makes it difficult to process the signal while maintaining an accurate, reliable output across the specified operating temperature and voltage ranges. Chopper stabilization is a unique approach used to minimize Hall offset on the chip. The patented Allegro technique, namely Dynamic Quadrature Offset Cancellation, removes key sources of the output drift induced by thermal and mechanical stresses. This offset reduction technique is based on a signal modulationdemodulation process. The unwanted offset signal is separated from the magnetic field-induced signal in the frequency domain, through modulation. The subsequent demodulation acts as a modulation process for the offset, causing the magnetic field induced signal to recover its original spectrum at baseband, while the DC offset becomes a high-frequency signal. The magnetic sourced signal then can pass through a low-pass filter, while the modulated DC offset is suppressed. This configuration is illustrated in figure 4. The chopper stabilization technique uses a 400 kHz, high frequency clock. For demodulation process, a sample-and-hold technique is used, where the sampling is performed at twice the chopper frequency (800 kHz). This high-frequency operation allows a greater sampling rate, which results in higher accuracy and faster signal-processing capability. This approach desensitizes the chip to the effects of thermal and mechanical stresses, and produces devices that have extremely stable quiescent Hall output voltages and precise recoverability after temperature cycling. This technique is made possible through the use of a BiCMOS process, which allows the use of low-offset, low-noise amplifiers in combination with high-density logic integration and sample-and-hold circuits. The repeatability of magnetic field-induced switching is affected slightly by a chopper technique. However, the Allegro high frequency chopping approach minimizes the affect of jitter and makes it imperceptible in most applications. Applications that are more likely to be sensitive to such degradation are those requiring precise sensing of alternating magnetic fields; for example, speed sensing of ring-magnet targets. For such applications, Allegro recommends its digital sensor IC families with lower sensitivity to jitter. For more information on those products, contact your Allegro sales representative. Regulator Hall Element Amp Sample and Hold Clock/Logic Low-Pass Filter Figure 4. Chopper stabilization circuit (Dynamic Quadrature Offset Cancellation) Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 11 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 Package LH, 5-Pin SOT23W +0.12 2.98 –0.08 0.20 MIN 4°±4° 5 A +0.02 0.18 –0.05 +0.10 2.90 –0.20 +0.19 1.91 –0.06 2.40 0.70 D 0.25 MIN 1.00 2 1 0.55 REF 0.25 BSC 0.95 Seating Plane Gauge Plane 8X 12° REF B PCB Layout Reference View Branded Face 1.00 ±0.13 SEATING PLANE 0.95 BSC +0.10 0.05 –0.05 0.40 ±0.10 NNN C 1 C Standard Branding Reference View N = Last three digits of device part number For Reference Only; not for tooling use Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Active Area Depth, 0.28 mm REF B Reference land pattern layout All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances C Branding scale and appearance at supplier discretion D Hall element, not to scale, location application dependant Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 12 Chopper-Stabilized Precision Hall-Effect Switch With Advanced Diagnostics A1160 Revision History Revision Revision Date – December 12, 2013 Initial Release Description of Revision 1 September 21, 2015 Added AEC-Q100 qualification under Features and Benefits Copyright ©2015, Allegro MicroSystems, LLC Allegro MicroSystems, LLC 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’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 13