Allegro MicroSystems A1334LLETR-T

Overview

A1334LLETR-T from Allegro MicroSystems is a precision 360° contactless Hall-effect angle sensor IC based on Circular Vertical Hall (CVH) technology, delivering 12-bit resolution in Low RPM mode and 10-bit resolution in High RPM mode, with configurable angle refresh rates from 25 µs to 200 µs, and optimized for 900 G magnetic field strength in automotive electronic power steering (EPS) systems.

For engineers reviewing the A1334LLETR-T datasheet, A1334LLETR-T pinout, A1334LLETR-T application, or A1334LLETR-T equivalent, this page provides verified technical context, validated pin functions for the 14-pin TSSOP package, confirmed operating parameters including ±0.6° angle error at 25°C, AEC-Q100 qualification status, and real-world selection guidance for redundant angle sensing designs.

Technical Context

The A1334LLETR-T implements a single-die system-on-chip (SoC) architecture integrating a CVH front end, digital signal processing with automotive-grade temperature compensation, EEPROM-based end-of-line calibration, and SPI interface - all operating over –40°C to +150°C ambient temperature with 4.5–14.5 V supply voltage.

It supports two configurable operational modes: Low RPM mode (200 µs refresh, 12-bit output) for high-resolution low-speed applications like throttle position sensing, and High RPM mode (25 µs refresh, 10-bit output) for fast-response EPS motor control, with both modes enabling magnet speed measurement beyond 7600 rpm and programmable zero-angle reference via SPI.

Key Specifications

Pinout & Package

Package: 14-pin TSSOP (LE-14), Pb-free with 100% matte-tin leadframe plating, 82 °C/W thermal resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar angle sensing applications.

Compared with A1334LLETR-T, the AS5055A offers higher raw resolution but lacks AEC-Q100 qualification and field-optimized CVH architecture, while the TLE5012B delivers superior noise performance and safety features at the cost of increased complexity and footprint - making A1334LLETR-T optimal for cost-sensitive, high-volume EPS deployments requiring proven field reliability.

Availability

A1334LLETR-T is available at Aetrix Electronics and suitable for automotive electronic power steering (EPS), throttle position sensing, and transmission gear selector applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for A1334LLETR-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 high-performance magnetic sensing and power ICs for automotive and industrial markets.

The A1334 product line was designed specifically for contactless, high-accuracy angular position measurement in safety-critical automotive subsystems, leveraging proprietary CVH technology to eliminate air-gap sensitivity and enable robust operation under extreme temperature and EMI conditions.

FAQ

What is the operating temperature range of the A1334LLETR-T?

The A1334LLETR-T operates over an ambient temperature range of –40°C to +150°C and is qualified to AEC-Q100 Grade 0 standards. This rating ensures reliable performance in under-hood automotive environments such as electronic power steering modules, where sustained high temperatures and thermal cycling are common. The device incorporates on-chip temperature compensation to maintain angle accuracy across this full range, with typical angle error remaining within ±1.75° at 150°C.

Does the A1334LLETR-T support dual-die redundancy?

No, the A1334LLETR-T is a single-die variant in a 14-pin TSSOP package. Dual-die functionality is available only in the A1334LLETR-DD-T (24-pin TSSOP) version. While the A1334LLETR-T itself does not contain two independent SoCs, its SPI interface and diagnostic features - including MAGM (missing magnet), BATD (loss of VCC), and IERR (watchdog) flags - are fully compatible with system-level redundancy architectures that integrate multiple A1334LLETR-T units on the same bus.

How is the A1334LLETR-T calibrated for zero-angle offset?

The A1334LLETR-T supports EEPROM-programmable zero-angle reference via SPI. During final calibration, the magnet is positioned at the desired mechanical zero-degree orientation, the raw angle output (AngleRAW) is read via SPI register 0x0, and that value is written to the Reference Angle register (0x20). The internal computation AngleOUT = AngleRAW – Reference Angle then yields true zero at that physical position. This process compensates for mechanical tolerances in magnet placement and housing alignment without requiring hardware modification.

What magnetic field strength is the A1334LLETR-T optimized for?

The A1334LLETR-T is factory-optimized for 900 G magnetic field strength, as indicated by the "900 G Field" note in the Selection Guide. This optimization improves signal-to-noise ratio and reduces angle noise by approximately 50% compared to operation at 300 G, while also lowering peak angle error. For best performance, users should select a magnet (e.g., 8 mm diameter × 2.5 mm thick NdFeB) delivering ~900 G at the sensor die surface, and verify field uniformity using Allegro's recommended test fixtures.

Is the A1334LLETR-T still in production?

No, the A1334LLETR-T is a discontinued product. Allegro MicroSystems officially marked the A1334 family as "no longer in production" with status change dated December 5, 2018. Samples are no longer available, and the device should not be purchased for new design applications. Customers are directed to transition to the A1338 family for new designs, which offers enhanced resolution, improved EMC immunity, and extended lifecycle support while maintaining pin and function compatibility in many configurations.