Allegro MicroSystems A1308LLHLT-05-T

Overview

A1308LLHLT-05-T from Allegro MicroSystems is a ratiometric linear Hall-effect sensor IC optimized for high-accuracy angular and displacement sensing in automotive and industrial systems. It delivers 0.5 mV/G sensitivity, ±1.5% linearity error, and operates from –40°C to 150°C in a 3-pin SOT-23W package with 2 mm × 3 mm × 1 mm footprint. Its quiescent output is centered at 2.5 V (50% of 5 V supply), enabling precise analog magnetic field measurement in throttle position, pedal position, and gear selector applications.

For engineers reviewing the A1308LLHLT-05-T datasheet, A1308LLHLT-05-T pinout, A1308LLHLT-05-T application, or A1308LLHLT-05-T equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternatives with documented differences, and supply-ready availability details - all specific to the A1308LLHLT-05-T variant.

Technical Context

The A1308LLHLT-05-T integrates a BiCMOS monolithic circuit with a Hall element, dynamic offset cancellation, temperature-compensating circuitry, and a high-gain amplifier. Its proprietary chopping scheme operates at 400 kHz to suppress thermal and mechanical drift, enabling stable quiescent voltage output (QVO) and sensitivity across temperature.

End-of-line programming sets both QVO and sensitivity temperature coefficients at 150°C, ensuring sustained accuracy over –40°C to 150°C. The device features undervoltage lockout (UVLO), output clamps (0.40–0.70 V low, 4.35–4.65 V high), and ratiometric behavior - all calibrated for 5 V supply operation with 9–11.5 mA supply current.

Key Specifications

Pinout & Package

Package: 3-pin SOT-23W (2.0 mm × 3.0 mm × 1.0 mm), lead-free with 100% matte-tin plating, optimized for surface-mount reflow assembly and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Hall-effect sensor applications.

Compared with A1308LLHLT-05-T, A1308LLHLX-05-T offers identical electrical performance and thermal rating but optimized for high-volume tape-and-reel handling, while TLV493D-A1B6 trades analog simplicity for digital flexibility and axis count - making it unsuitable for direct replacement in existing analog-signal-path designs.

Availability

A1308LLHLT-05-T is available at Aetrix Electronics and suitable for automotive powertrain control, industrial motor feedback, and precision position sensing applications requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for A1308LLHLT-05-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensing and power ICs, founded in 1989 and headquartered in Manchester, NH.

The A1308 family was developed specifically for high-accuracy, high-temperature linear position sensing in automotive and industrial systems - emphasizing end-of-line programmability, ratiometric stability, and robust EMC performance.

FAQ

What is the operating temperature range of the A1308LLHLT-05-T?

The A1308LLHLT-05-T is rated for –40°C to +150°C ambient operation, validated per AEC-Q100 Grade 0 requirements. This range applies specifically to the SOT-23W (LH) package variant and enables deployment in under-hood automotive locations and high-heat industrial motor enclosures where conventional sensors fail.

Does the A1308LLHLT-05-T require an external bypass capacitor?

Yes, the A1308LLHLT-05-T requires a 0.1 µF ceramic bypass capacitor between VCC and GND, placed as close as possible to the pins. This capacitor stabilizes the internal regulator, reduces noise coupling, and ensures proper operation of the chopping circuitry and output stage - omission causes increased output noise and potential instability.

How does the A1308LLHLT-05-T achieve its high linearity specification?

The A1308LLHLT-05-T achieves ±1.5% linearity through factory-programmed end-of-line optimization of sensitivity and quiescent voltage, combined with dynamic offset cancellation and high-precision BiCMOS analog signal conditioning. These techniques correct for Hall element nonlinearity and process variation, ensuring consistent response across its full magnetic input range.

Can the A1308LLHLT-05-T be used with a 3.3 V supply?

No, the A1308LLHLT-05-T is specified only for 4.5–5.5 V operation. Its internal circuitry, including the Hall element bias, amplifier gain, and UVLO thresholds, is designed around a 5 V nominal supply. Using 3.3 V will prevent proper startup (VUVLOHI = 3 V minimum) and result in undefined output behavior or no output.

What diagnostic capabilities does the A1308LLHLT-05-T provide?

The A1308LLHLT-05-T provides two hardware-level diagnostics: (1) output voltage clamps (0.40–0.70 V low, 4.35–4.65 V high) that indicate short-to-ground or short-to-rail faults, and (2) undervoltage lockout (UVLO) that forces VOUT low when VCC drops below 2.5 V - both enabling fail-safe system responses without additional monitoring circuitry.