Allegro MicroSystems A1309LUATN-9-T

Overview

A1309LUATN-9-T from Allegro MicroSystems is a forward-polarity, ratiometric linear Hall-effect sensor IC optimized for high-accuracy angular and displacement sensing in automotive and industrial systems. It delivers 9 mV/G sensitivity, ±1.5% linearity error, and operates from –40°C to +125°C in a 3-pin SIP through-hole package with 1.5 mm × 4 mm × 3 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 A1309LUATN-9-T datasheet, A1309LUATN-9-T pinout, A1309LUATN-9-T application, or A1309LUATN-9-T equivalent, key selection criteria include its AEC-Q100 qualification, temperature-compensated QVO drift ≤ ±10 mV over –40°C to 125°C, 20 kHz bandwidth, 400 kHz chopping frequency, and integrated undervoltage lockout with 2.5 V turn-off threshold.

Technical Context

The A1309LUATN-9-T integrates a BiCMOS monolithic circuit featuring a Hall element, dynamic offset cancellation, temperature-compensating circuitry, and a high-gain amplifier. Its proprietary chopper stabilization scheme operates at 400 kHz to suppress thermal and mechanical stress-induced offset drift, ensuring stable quiescent voltage output across temperature.

End-of-line programming sets both sensitivity temperature coefficient (0.08–0.16 %/°C) and QVO temperature coefficient, enabling sustained accuracy across –40°C to 125°C. Output clamps (0.40–0.70 V low, 4.35–4.65 V high) provide short-circuit diagnostics, while ratiometric behavior ties all key parameters-QVO, sensitivity, and clamp voltages-to the 4.5–5.5 V supply rail.

Key Specifications

Pinout & Package

Package: 3-pin ultramini SIP (UA), through-hole mount, 1.5 mm × 4 mm × 3 mm, lead-free with 100% matte-tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with A1309LUATN-9-T, the A1309LLHLX-9-T offers identical sensitivity and enhanced temperature range in a smaller SMT package, while the TLV493D-A1B6 provides digital 3D sensing at lower voltage but sacrifices ratiometric stability, analog diagnostics, and automotive qualification.

Availability

A1309LUATN-9-T is available at Aetrix Electronics and suitable for automotive throttle control, industrial valve positioning, gear selector feedback, and pedal position monitoring requiring stable component supply and AEC-Q100 compliance.

Supply support for A1309LUATN-9-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 semiconductor company specializing in magnetic sensing, power ICs, and precision motion control solutions.

The A1308/A1309 family was designed for high-accuracy, temperature-stable linear position sensing in automotive powertrain and industrial actuation systems-emphasizing end-of-line calibration, ratiometric stability, and robust EMC performance.

FAQ

What is the operating temperature range for the A1309LUATN-9-T?

The A1309LUATN-9-T is rated for an operating ambient temperature range of –40°C to +125°C. This specification applies specifically to the UA-package variant (3-pin SIP) and is validated per AEC-Q100 Grade 1 requirements. The device maintains specified sensitivity (8.73–9.27 mV/G), QVO (2.488–2.512 V), and linearity (±1.5%) across this full range due to factory-programmed temperature coefficients.

Does the A1309LUATN-9-T require an external bypass capacitor?

Yes, the A1309LUATN-9-T requires a 0.1 µF ceramic bypass capacitor between VCC and GND, placed as close as possible to the package pins. This capacitor stabilizes the internal regulator and suppresses high-frequency noise from the 400 kHz chopper circuit. Layout guidelines specify minimum pad spacing and copper area to ensure thermal resistance remains within spec (R_θJA = 165 °C/W for UA package on 1-layer PCB).

How does the undervoltage lockout (UVLO) function in the A1309LUATN-9-T?

The A1309LUATN-9-T implements UVLO with two thresholds: it powers on when VCC exceeds 3 V (V_UVLOHI) and powers off when VCC drops below 2.5 V (V_UVLOLO). During UVLO, VOUT is actively pulled low to GND. This hysteresis prevents oscillation near the threshold and ensures clean startup/shutdown. The feature is tested across the full –40°C to 125°C range and is integral to AEC-Q100 compliance for automotive use cases.

What is the purpose of the output voltage clamps in the A1309LUATN-9-T?

The A1309LUATN-9-T features output clamps at 0.40–0.70 V (low) and 4.35–4.65 V (high), which serve dual purposes: (1) they prevent output saturation during strong magnetic fields, preserving linearity up to ±550 G; and (2) they enable short-circuit diagnostics-if VOUT is stuck near either clamp under zero-field conditions, it indicates wiring faults or load failures. Clamps scale ratiometrically with VCC, maintaining diagnostic validity across supply variations.

Is the A1309LUATN-9-T pin-compatible with other A1308/A1309 variants?

Yes-the A1309LUATN-9-T shares identical pinout (VCC–VOUT–GND), package dimensions (1.5 mm × 4 mm × 3 mm UA), and terminal assignments with all other UA-package A1308/A1309 variants (e.g., A1308KUATN-2-T). This allows direct substitution within the same footprint when sensitivity or temperature grade differs, provided system-level validation confirms compatibility with the new sensitivity (9 mV/G) and thermal profile (–40°C to 125°C).