ALS31000 ALLEGRO
Document overview
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Technical content
DESCRIPTION
New applications for linear output Hall-effect sensors, such as displacement and angular position, require higher accuracy and smaller package sizes. The Allegro ALS31000 linear Hall-effect sensor IC has been designed specifically to meet both requirements. The accuracy of this device is enhanced via end-of-line optimization. The ALS31000 features non-volatile memory to optimize device sensitivity and the quiescent voltage output (QVO: output in the absence of a magnetic field) for a given application or circuit. Optimized performance is sustained across the full operating temperature range by programming the temperature coefficient for both sensitivity and QVO at Allegro end-of-line test. This ratiometric Hall-effect sensor IC provides a voltage output proportional to the applied magnetic field. The quiescent voltage output is adjusted to around 0.7 V and the output sensitivity is set to 2.4 mV/G. The features of this linear device make it ideal for use in automotive and industrial applications requiring high accuracy and operation across an extended temperature range, –40°C to 150°C. Each BiCMOS monolithic circuit integrates: a Hall element, temperature-compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, a clamped low-impedance output stage, and a proprietary dynamic offset cancellation technique. ALS31000-DS, Rev. 2 MCO-0000575 FEATURES AND BENEFITS
- 5 V supply operation
- QVO temperat ure coefficient programmed at Allegro™ for improved accuracy
- Miniature pack age options
- High-bandwidth, low-noise an alog output
- High-speed ch opping scheme minimizes QVO drift across operating temperature range
- T emperature-stable quiescent voltage output and sensitivity
- Precise recove rability after temperature cycling
- Output voltage clamps provide short-circuit diagnostic capabilities
- Undervoltage l ockout (UVLO)
- W ide ambient temperature range: –40°C to 150°C
- Immune to me chanical stress
- Enhanced EMC performance f or stringent automotive
applications
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount Package Continued on the next page… Functional Block Diagram ALS31000 VCC Offset and Offset TC Sensitivity and Dynamic Offset Cancellation Tuned Filter Sensitivity TC VCC CBYPASS GND VOUT Package: Not to scale 3-pin SOT23-W 2 mm × 3 mm × 1 mm (suffix LH) February 19, 2019
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A. www.allegromicro.com DESCRIPTION (CONTINUED) ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Unit Forward Supply Voltage VCC 8 V Reverse Supply Voltage VRCC –0.1 V Forward Output Voltage VOUT 7 V Reverse Output Voltage VROUT –0.1 V Output Source Current IOUT(SOURCE) VOUT to GND 2 mA Output Sink Current IOUT(SINK) VCC to VOUT 10 mA Operating Ambient Temperature TA Range L –40 to 150 °C Maximum Junction Temperature TJ(max) 165 °C Storage Temperature Tstg –65 to 170 °C The ALS31000 sensor IC is offered in the LH package style: a SOT-23W style, miniature, low-profile package for surface-mount applications. The package is lead (Pb) free, with 100% matte-tin leadframe plating. SELECTION GUIDE Part Number Packing* Package ALS31000LLHALX 10,000 pieces per reel 3-pin SOT-23W surface-mount *Contact Allegro™ for additional packing options Terminal List Table Name Number Description VCC 1 Input power supply; tie to GND with bypass capacitor VOUT 2 Output signal GND 3 Ground THERMAL CHARACTERISTICS: May require derating at maximum conditions; see application information Characteristic Symbol Test Conditions 1 Value Units Package Thermal Resistance RθJA Package LH, 1-layer PCB with copper limited to solder pads 228 °C/W Package LH, 2-layer PCB with 0.463 in.2 of copper area each side connected by thermal vias 110 °C/W
1 Additional thermal information available on Allegro website
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com OPERATING CHARACTERISTICS: Valid over TA , CBYPASS = 0.1 µF, VCC = 5 V, unless otherwise noted Characteristic Symbol Test Conditions Min. Typ. Max. Unit 2 Continued on the next page…
ELECTRICAL CHARACTERISTICS
Supply Voltage VCC 4.5 5.0 5.5 V Undervoltage Threshold 3 VUVLOHI Tested at TA = 25°C and TA = 150°C (device powers-on) – – 3 V VUVLOLO Tested at TA = 25°C and TA = 150°C (device powers-off) 2.5 – – V Supply Current ICC No load on VOUT – 9 11.5 mA Power-On Time 4,5 tPO TA = 25°C, CL(PROBE) = 10 pF – 50 – µs VCC Ramp Time 4,5 tVCC TA = 25°C 0.005 – 100 ms VCC Off Level 4,5 VCCOFF TA = 25°C 0 – 0.55 V Delay to Clamp 4,5 tCLP TA = 25°C, CL = 10 nF – 30 – µs Supply Zener Clamp Voltage VZ TA = 25°C, ICC = 14.5 mA 6 7.3 – V Internal Bandwidth 5 BWi Small signal –3 dB – 20 – kHz Chopping Frequency 5,6 fC TA = 25°C – 400 – kHz OUTPUT CHARACTERISTICS Output Referred Noise 5 VN VCC = 5 V, TA = 25°C, CBYPASS = open, no load on VOUT – 4 – mV(p-p) Input Referred RMS Noise Density 5 VNRMS VCC = 5 V, TA = 25°C, CBYPASS = open, no load on VOUT, fmeasured ≪ BWi – 1.5 – mG/√Hz DC Output Resistance 5 ROUT – <1 – Ω Output Load Resistance 5 RL VOUT to GND 4.7 – – kΩ Output Load Capacitance 5 CL VOUT to GND – – 10 nF Output Voltage Clamp 7,8 VCLPHIGH TA = 25°C, RL = 10 kΩ (VOUT to GND) 4.35 4.5 4.65 V VCLPLOW TA = 25°C, RL = 10 kΩ (VOUT to VCC) 0.37 0.51 0.65 V Sensitivity Sens TA = 25°C 2.304 2.4 2.496 mV/G Quiescent Voltage Output (QVO) VOUT(Q) TA = 25°C 0.68 0.7 0.72 V Sensitivity Temperature Coefficient TCSens Programmed at TA = 150°C, calculated relative to Sens at 25°C 0.08 0.12 0.16 %/°C
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com OPERATING CHARACTERISTICS (continued): Valid over TA , CBYPASS = 0.1 µF, VCC = 5 V, unless otherwise noted Characteristic Symbol Test Conditions Min. Typ. Max. Unit 2 ERROR COMPONENTS Linearity Sensitivity Error LinERR – ±1.5 – % Ratiometry Quiescent Voltage Output Error 9 RatVOUT(Q) Across supply voltage range (relative to VCC = 5 V) – ±1.5 – % Ratiometry Sensitivity Error 9 RatSens Across supply voltage range (relative to VCC = 5 V) – ±1.5 – % Ratiometry Clamp Error 10 RatVOUTCLP TA = 25°C, across supply voltage range (relative to VCC = 5 V) – ±1.5 – % DRIFT CHARACTERISTICS Typical Quiescent Voltage Output Drift Across Temperature Range ∆VOUT(Q) TA = 150°C –10 – 20 mV Sensitivity Drift Due to Package Hysteresis 11 ∆SensPKG TA = 25°C, after temperature cycling – ±2 – % 2 1 G (gauss) = 0.1 mT (millitesla), 3 On power-up, the output of the device is held low until VCC exceeds VUVLOHI. After the device is powered, the output remains valid until VCC drops below VUVLOLO , when the output is pulled low . 4 See the Characteristic Definitions section. 5 Determined by design and characterization; not evaluated at final test. 6 fC varies as much as approximately ±20% across the full operating ambient temperature range and process. 7 Parameter is tested at wafer probe only. 8 VCLPLOW and VCLPHIGH scale with VCC due to ratiometry. 9 Percent change from actual value at VCC = 5 V, for a given temperature. 10 Percent change from actual value at VCC = 5 V, TA = 25°C. 11 Sensitivity drift through the life of the part, ΔSensLIFE , can have a typical error value ±3% in addition to package hysteresis effects.
Manchester, NH 03103-3353 U.S.A. CC (min), as shown in figure 1. its steady-state voltage, as shown in figure 2. ing ranges of VCC and Operating Ambient Temperature, TA. where B1 and B2 are two magnetic fields of different magnitude. and T2 is the TCSENS programming temperature of 150°C. Figure 1. Definition of Power On Time, tPO Figure 2. Definition of Delay to Clamp, tCLP
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com operating ambient temperature range, TA. For purposes of specifi- cation, the Sensitivity Drift Across Temperature Range, ∆SensTC, is defined as: SensTA – SensIDEAL(TA) SensIDEAL(TA) ∆SensTC = × 100 (%) (5) Sensitivity Drift Due to Package Hysteresis. Package stress and relaxation can cause the device sensitivity at TA = 25°C to change during and after temperature cycling. This change in sensitivity follows a hysteresis curve. For purposes of specifica- tion, the Sensitivity Drift Due to Package Hysteresis, ∆SensPKG, is defined as: Sens(25°C)(2) – Sens(25°C)(1) Sens(25°C)(1) ∆SensPKG = × 100 (%) (6) where Sens(25°C)(1) is the programmed value of sensitivity at TA = 25°C, and Sens(25°C)(2) is the value of sensitivity at TA = 25°C after temperature cycling TA up to 150°C, down to –40°C, and back to up 25°C. Linearity Sensitivity Error. The ALS31000 is designed to provide linear output in response to a ramping applied magnetic field. Consider two magnetic fields, B1 and B2. Ideally, the sen- sitivity of a device is the same for both fields, for a given supply voltage and temperature. Linearity error is present when there is a difference between the sensitivities measured at B1 and B2. Linearity error (%) is measured and defined as: Sens(B2) Sens(B1) 1–LinERR = × 100 (%) (7) where: |VOUT(Bx) – VOUT(Q)| BxSensBx = (8) and B1 and B2 are positive magnetic fields, with respect to the quiescent voltage output, such that |B2| > |B1|. The output voltage clamps, VCLPHIGH and VCLPLOW , limit the operating magnetic range of the applied field in which the device provides a linear output. The maximum positive and negative applied magnetic fields in the operating range can be calculated: VCLPHIGH – VOUT(Q) SensBMAX(+) = VOUT(Q) – VCLPLOW SensBMAX(–) = (9) Ratiometry Error. The ALS31000 provides ratiometric out- put. This means that the Quiescent V oltage Output, VOUT(Q) , magnetic sensitivity, Sens, and clamp voltages, VCLPHIGH and VCLPLOW , are proportional to the supply voltage, VCC. When the supply voltage increases or decreases by a certain percent- age, each characteristic also increases or decreases by the same percentage. Error is the difference between the measured change in the supply voltage relative to 5 V , and the measured change in each characteristic. The ratiometric error in quiescent voltage output, Rat VOUT(Q) (%), for a given supply voltage, VCC, is defined as: VOUT(Q)(VCC) / VOUT(Q)(5V) VCC / 5 (V)1–RatVOUT(Q) = × 100 (%) (11) The ratiometric error in magnetic sensitivity, RatSens (%), for a given supply voltage, VCC, is defined as: Sens(VCC) / Sens(5V) VCC / 5 (V)1–RatSens = × 100 (%) (12) The ratiometric error in the clamp voltages, RatVOUTCLP (%), for a given supply voltage, VCC, is defined as: VCLP(VCC) / VCLP(5V) VCC / 5 (V)1–RatVOUTCLP = × 100 (%) (13) where VCLP is either VCLPHIGH or VCLPLOW . (10)
Manchester, NH 03103-3353 U.S.A. eliminate indeterminate output states. VCC(typ), 5 V (see Figure 4). of the device (see Figure 4). Figure 3. UVLO Operation Figure 4. Definition of VCC Ramp Time, tVCC
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com ALS31000 VOUT GND0.15 V µF RL VCC 4.7 nF
APPLICATION INFORMATION
Figure 5. Typical Application Circuit Figure 6. Chopper Stabilization Technique technique is based on a signal modulation-demodulation process. density logic integration and sample-and-hold circuits.
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com Package LH, 3-Pin SOT-23W
0.55 REF
0.25 BSC
0.95 BSC
0.95 1.00 0.70 2.40 A Active Area Depth, 0.28 mm REF B C C 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 Branding scale and appearance at supplier discretion A PCB Layout Reference View Branding Reference View Branded Face 2.90 +0.10 –0.20 4°±4° 0.180+0.020 –0.053 0.05 +0.10 –0.05
0.25 MIN
1.91 +0.19 –0.06 2.98 +0.12 –0.08 1.00 ±0.13 A30 0.40 ±0.10 For Reference Only; not for tooling use (reference DWG-2840) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown D Hall element, not to scale D D D1.49 0.96
Unidirectional Linear Hall-Effect Sensor IC with Analog Output, in Miniature Low-Profile Surface-Mount PackageALS31000 Allegro MicroSystems, LLC Manchester, NH 03103-3353 U.S.A. www.allegromicro.com For the latest version of this document, visit our website: www.allegromicro.com Copyright ©2019, 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. Copies of this document are considered uncontrolled documents.
Revision History
– September 6, 2016 Initial release