A1318

A1318
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A1318

Product catalog summary
Overview: The Allegro A1318 and A1319 are linear Hall-effect sensor ICs designed for high accuracy in displacement and angular position applications. They are temperature-stable and available in both surface-mount and through-hole packages, optimized for sensitivity and quiescent voltage output (QVO).
Specifications: These sensors operate with a 3.3V supply and feature a wide ambient temperature range from -40°C to 150°C. They include a high-bandwidth, low-noise analog output, and are immune to mechanical stress with enhanced EMC performance for automotive applications.
Features and Benefits: Key features include a high-speed chopping scheme to minimize QVO drift, precise recoverability after temperature cycling, output voltage clamps for diagnostic capabilities, and undervoltage lockout (UVLO). The devices are available in miniature package options, making them suitable for space-constrained applications.
Absolute Maximum Ratings: The sensors have a forward supply voltage of 8V, reverse supply voltage of -0.1V, and can operate within a temperature range of -40°C to 150°C. The maximum junction temperature is 165°C, and storage temperature ranges from -65°C to 170°C.
Package Options: The A1318 and A1319 are available in two package styles: the SOT-23W for surface-mount applications and the 3-pin SIP for through-hole mounting. Both are lead-free with 100% matte-tin leadframe plating.
Electrical Characteristics: The sensors have a supply voltage range of 3 to 3.63V, with a typical supply current of 7.7mA. They feature a power-on time of 50µs and an internal bandwidth of 20kHz. The output characteristics include a DC output resistance of less than 1Ω and an output load resistance of 4.7kΩ.
Performance Metrics: Sensitivity is specified in mV/G, with variants offering different sensitivity levels. The quiescent voltage output is around 1.65V, and sensitivity temperature coefficient is programmed at 150°C. Linearity sensitivity error and ratiometry errors are within ±1.5%.
Applications: These sensors are ideal for automotive and industrial applications requiring high accuracy and reliability across a wide temperature range.
Ratiometric Error: The document defines ratiometric errors for quiescent voltage output, magnetic sensitivity, and clamp voltages, providing formulas to calculate these errors based on changes in supply voltage.
Undervoltage Lockout: The A1318 and A1319 include an undervoltage lockout feature that ensures the device outputs a signal only when VCC is above certain thresholds, providing operational hysteresis to prevent indeterminate output states.
Chopper Stabilization Technique: This technique is employed to minimize Hall offset and improve accuracy by separating the offset signal from the magnetic field-induced signal through modulation and demodulation processes. This approach enhances stability and reduces thermal noise.
Application Information: The document includes typical application circuits and details on the chopper stabilization technique, which uses a high-frequency sampling clock and sample-and-hold technique to improve accuracy and signal processing capabilities.
Package Information: Detailed dimensions and layout guidelines for the SOT-23W and SIP packages are provided, including reference views and branding information.
Revision History: The document includes a revision history, noting updates to product offerings and selection guide tables.
Disclaimer: Allegro MicroSystems reserves the right to make changes to improve performance and reliability. The document cautions against using these products in life support systems where failure could cause harm.
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Catalog excerpts

A1318-1

A1318 and A1319 Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package Features and Benefits • 3.3 V supply operation • QVO temperature coefficient programmed at Allegro™ for improved accuracy • Miniature package options • 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 • Output voltage clamps provide short-circuit diagnostic capabilities • Undervoltage lockout (UVLO) • Wide ambient temperature range: –40°C to 150°C • Immune to mechanical stress • Enhanced EMC performance for stringent automotive applications New applications for linear output Hall-effect sensors, such as displacement and angular position, require higher accuracy and smaller package sizes. The Allegro A1318 and A1319 linear Hall-effect sensor ICs have been designed specifically to meet both requirements. These temperature-stable devices are available in both surface-mount and through-hole packages. The accuracy of each device is enhanced via end-of-line optimization. Each device 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. This A1318 and A1319 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. These ratiometric Hall-effect sensor ICs provide a voltage output that is proportional to the applied magnetic field. The quiescent voltage output is adjusted around 50% of the supply voltage. The features of these linear devices make them ideal for use in automotive and industrial applications requiring high accuracy, and operate 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 Continued on the next page… Functional Block Diagram V+ Tuned Filter Dynamic Offset Cancellation

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A1318-2

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package DESCRIPTION (continued) sensitivity drift ofthe Hall element, a small-signal high-gain amplifier, a clamped low-impedance output stage, and a proprietary dynamic offset cancellation technique. The A1318 and A1319 sensor ICs are offered in two package styles. The LH is a SOT-23W style, miniature, low-profile package for surface-mount applications. The UA is a 3-pin, ultramini, single inline package (SIP) for through-hole mounting. Both packages are lead (Pb) free, with 100% matte-tin leadframe...

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A1318-3

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package Pinout Diagrams Terminal List Table THERMAL CHARACTERISTICS: May require derating at maximum conditions; see application information 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com

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A1318-4

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package OPERATING CHARACTERISTICS: Valid over TA , CBYPASs = 0.1 pF, VCC = 3.3 V, unless otherwise noted Continued on the next page... 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com

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A1318-5

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package OPERATING CHARACTERISTICS (continued): Valid over TA , CBYPASs = 0-1 pF, VCC = 3.3 V, unless otherwise noted I1! 1 G (gauss) = 0.1 mT (millitesla), I2! 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. [3] See the Characteristic Definitions section. [4] Determined by design and characterization, not evaluated at final test. t5] fC varies as much...

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A1318-6

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package Characteristic Definitions Power-On Time. When the supply is ramped to its operating voltage, the device output requires a finite time to react to an input magnetic field. Power-On Time, tPO , is defined as the time it takes for the output voltage to begin responding to an applied magnetic field after the power supply has reached its minimum specified operating voltage, VCC(min), as shown in figure 1. Delay to Clamp. A large magnetic input step may cause the clamp to overshoot its steady...

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A1318-7

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package the Sensitivity Drift Across Temperature Range, ∆SensTC, is defined as: SensTA – SensIDEAL(TA) ∆SensTC = × 100 (%) SensIDEAL(TA) 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 specification, the Sensitivity Drift Due to Package Hysteresis, ∆SensPKG, is defined as: where Sens(25°C)(1) is the programmed...

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A1318-8

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package Undervoltage Lockout. The A1318 and A1319 provide 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 A1318 and A1319 is held low (GND) until VCC exceeds VUVLOHI . After VCC exceeds VUVLOHI , the device VOUT output is enabled, providing a ratiometric output voltage that is proportional...

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