A1304ELHLX-T

A1304 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package FEATURES AND BENEFITS • • • • • DESCRIPTION 3.3 V supply operation Allegro factory-programmed offset and sensitivity Miniature package High-bandwidth, low-noise analog output High-speed chopping scheme minimizes QVO drift across operating temperature range Temperature-stable quiescent voltage output and sensitivity Precise recoverability after temperature cycling Wide ambient temperature range: –40°C to 85°C Immune to mechanical stress New applications for linear output Hall-effect sensors require medium accuracy and smaller package size. The Allegro A1304 linear Hall-effect sensor IC has been designed specifically to achieve both goals. This temperature-stable device is available in a miniature surface mount package (SOT23-W). Package: 3-Pin Surface Mount SOT23-W (suffix LH) The A1304 sensor IC is available in a 3-pin surface mount SOT-23W style package (LH suffix). The package is lead (Pb) free, with 100% matte tin leadframe plating. • • • • This ratiometric Hall-effect sensor provides a voltage output that is proportional to the applied magnetic field and features a quiescent voltage output of 50% of the supply voltage. Each BiCMOS monolithic circuit integrates a Hall element, offset and sensitivity trim circuitry to correct for the variation in the Hall element, a small-signal high-gain amplifier, and a proprietary dynamic offset cancellation technique. Approximate footprint Not to scale V+ CBYPASS Tuned Filter Dynamic Offset Cancellation VCC Sensitivity VOUT Offset Trim Control GND Functional Block Diagram A1304-DS, Rev. 3 MCO-0000508 September 30, 2019 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package A1304 SELECTION GUIDE Part Number Sensitivity (typ)(mV/G) Packing* Package A1304ELHLX-T 4.0 10,000 pieces per reel 3-pin SOT-23W surface mount A1304ELHLX-05-T 0.5 10,000 pieces per reel 3-pin SOT-23W surface mount *Contact Allegro™ for additional packing options ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Unit Forward Supply Voltage VCC 5.5 V Reverse Supply Voltage VRCC –0.1 V Forward Output Voltage VOUT Reverse Output Voltage VROUT Output Source Current IOUT(SOURCE) VOUT to GND 1 mA IOUT(SINK) VCC to VOUT 5 mA Output Sink Current For IOUT < IOUT(SINK) 7 V –0.1 V Operating Ambient Temperature TA –40 to 85 °C Maximum Junction Temperature TJ(max) 165 °C Tstg –65 to 170 °C Storage Temperature Range E THERMAL CHARACTERISTICS: May require derating at maximum conditions; see application information Characteristic Symbol Test Conditions* Value Units 228 °C/W 110 °C/W Package LH, 1-layer PCB with copper limited to solder pads Package Thermal Resistance RθJA Package LH, 2-layer PCB with 0.463 connected by thermal vias in.2 of copper area each side *Additional thermal information available on the Allegro website PINOUT DRAWING AND TERMINAL LIST Terminal List Table 3 Name 1 2 LH Package, 3-Pin SOT23-W Pinout Diagram Number Description VCC 1 Input power supply; tie to GND with bypass capacitor VOUT 2 Output signal GND 3 Ground Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 2 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package A1304 OPERATING CHARACTERISTICS: Valid across TA, CBYPASS = 0.1 µF, VCC = 3.3 V, unless otherwise noted Characteristic Symbol Test Conditions Min. Typ. Max. Unit [1] 3 – 3.6 V ELECTRICAL CHARACTERISTICS Supply Voltage VCC Supply Current ICC No load on VOUT – 7.7 9 mA Power-On Time [2][3] tPO TA = 25°C, CL = 10 nF – 50 70 µs tVCC TA = 25°C 0.005 – 100 ms VCCOFF TA = 25°C 0 – 0.33 V Small signal –3 dB – 20 – kHz – 13 – mV(p–p) – 13 – mV(p–p) – 2.3 – mG / √Hz – 4.6 – mG / √Hz – |B(–)(1)| The effective linearity error is: LinERR = max(|LinERR+| , |LinERR– |) (7) The saturation of the output at VSAT(HIGH) and VSAT(LOW) will 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: BMAX(+)  = BMAX(–)  = or decreases by a certain percentage, each characteristic also increases or decreases by the same percentage. Error is the difference between the measured change in the supply voltage relative to 3.3 V, and the measured change in each characteristic. The ratiometric error in quiescent voltage output, RatVOUT(Q) (%), for a given supply voltage, VCC, is defined as:  VOUT(Q)(VCC) / VOUT(Q)(3.3V)   × 100 RatVOUT(Q) = 1– VCC / 3.3 (V)   VOUT(Q) – VSAT(LOW) (8) Sens Ratiometry Error. The A1304 provides ratiometric output. This means that the Quiescent Voltage Output, VOUT(Q) , and the magnetic sensitivity, Sens, are proportional to the supply voltage, VCC. In other words, when the supply voltage increases (9) The ratiometric error in magnetic sensitivity, RatSens (%), for a given supply voltage, VCC, is defined as:  Sens(VCC) / Sens(3.3V)  × 100 (%) RatSens = 1– VCC / 3.3 (V)   VSAT(HIGH) – VOUT(Q) Sens (%) (10) VCC Ramp Time. The time taken for VCC to ramp from 0 V to VCC(typ), 3.3 V (see figure 3). VCC Off Level. For applications in which the VCC pin of the A1304 is being power-cycled (for example using a multiplexer to toggle the part on and off), the specification of VCC Off Level, VCCOFF , determines how high a VCC off voltage can be tolerated while still ensuring proper operation and startup of the device (see Figure 3). Output Voltage, VOUT (V) VSAT(High) Supply Voltage, VCC (V) VCC(typ) VOUT(Q) VSAT(Low) –B 0 +B tVCC VCCOFF 0 time Appied Magnetic Field Intensity, B (G) Figure 2: Effect of Saturation Figure 3: Def inition of VCC Ramp Time, tVCC Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 5 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package A1304 Undervoltage Lockout. The A1304 provides an undervoltage lockout feature which ensures that the device outputs a VOUT signal only when VCC is above certain thresholds . The undervoltage lockout feature provides a hysteresis of operation to eliminate indeterminate output states. The output of the A1304 is held low (GND) until VCC exceeds the VCC rising UVLO reset threshold. After that , the device VOUT output is enabled, providing a ratiometric output voltage that is proportional to the input magnetic signal and VCC . If VCC should drop back down below the VCC falling UVLO trip threshold after the device is powered up, the output would be pulled low (see Figure 4) until VCC rising UVLO reset threshold is reached again and VOUT would be reenabled. VCC (V) 3.0 2.8 2.6 VCC(min) VCC rising UVLO Reset VCC falling UVLO trip Reduced perfomance Reduced perfomance Undervoltage Lockout Undervoltage Lockout t VOUT (V) VCC / 2 VOUT is near ground potential when A1304 is in UVLO state 2.6 VCC falling UVLO trip 2.8 VCC (V) VCC rising UVLO Reset Figure 4: UVLO Operation Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 6 A1304 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package APPLICATION INFORMATION A1304 VOUT VCC 0.1 µF 3.3 V RL GND 4.7 nF Figure 5: Typical Application Circuit 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 sensor IC. This makes it difficult to process the signal while maintaining an accurate, reliable output over the specified operating temperature and voltage ranges. Chopper stabilization is a unique approach used to minimize Hall offset on the chip. Allegro employs a technique to remove key sources of the output drift induced by thermal and mechanical stresses. This offset reduction technique is based on a signal modulation-demodulation process. The undesired offset signal is separated from the magnetic fieldinduced 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 base band, 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. In addition to the removal of the thermal and mechanical stress related offset, this novel technique also reduces the amount of thermal noise in the Hall sensor IC while completely removing the modulated residue resulting from the chopper operation. The chopper stabilization technique uses a high frequency sampling clock. For demodulation process, a sample and hold technique is used. 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 highdensity logic integration and sample-and-hold circuits. Regulator Clock/Logic Hall Element Amp Anti-aliasing Tuned LP Filter Filter Figure 6: Chopper Stabilization Technique Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 7 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package A1304 PACKAGE OUTLINE DIAGRAM For Reference Only – Not for Tooling Use (Reference DWG-2840) Dimensions in millimeters – NOT TO SCALE Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown +0.12 2.98 –0.08 D 1.49 4°±4° A 3 0.180 +0.020 –0.053 0.96 D 2.90 +0.10 –0.20 1.91 +0.19 –0.06 2.40 0.70 D 0.25 MIN 1.00 2 1 0.55 REF 0.25 BSC 0.95 Seating Plane B Gauge Plane 8X 10° REF PCB Layout Reference View Branded Face 1.00 ±0.13 0.05 0.95 BSC +0.10 –0.05 0.40 ±0.10 NNN C Standard Branding Reference View N = Last three digits of device part number A Active Area Depth, 0.28 mm 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 elements, not to scale Figure 7: Package LH, 3-Pin (SOT-23W) Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 8 A1304 Linear Hall-Effect Sensor IC with Analog Output, Available in a Miniature, Low-Profile Surface Mount Package Revision History Number Date Description – June 16, 2014 Initial Release 1 July 13, 2015 Corrected LH package Active Area Depth value 2 September 18, 2018 Clarified Absolute Maximum Ratings; minor editorial updates 3 September 30, 2019 Minor editorial updates Copyright 2019, Allegro MicroSystems. Allegro MicroSystems 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 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. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 9