Allegro MicroSystems A1337LLETR-P-T

Overview

A1337LLETR-P-T from Allegro MicroSystems is a contactless, 0° to 360° Hall-effect angle sensor IC with dual SPI and SENT outputs, 12-bit resolution in low-RPM mode, 25 µs refresh rate in high-RPM mode, and integrated turns counter for CW/CCW rotation tracking - deployed in automotive electronic power steering (EPS) and throttle position sensing.

For engineers reviewing the A1337LLETR-P-T datasheet, A1337LLETR-P-T pinout, A1337LLETR-P-T application, or A1337LLETR-P-T equivalent, this page delivers verified technical context, real-world diagnostic capabilities (LBIST, 4-bit CRC, missing-magnet flag), low-power mode current (55 µA/die), EEPROM-programmable angle reference, and dual-die redundancy support - all critical for ASIL-B functional safety design.

Technical Context

The A1337LLETR-P-T implements a dual-independent SoC architecture with two electrically isolated CVH front ends, each featuring its own regulator, EEPROM with ECC, SPI (mode 3, 10 MHz max), and SENT output supporting SAE J2716, TSENT, SSENT, and ASENT protocols. It uses circular vertical Hall technology for air-gap–independent angular measurement.

It supports programmable low-power mode (85 µA typical per die), ultralow-power transport mode (30 µA at 150°C), and wake-up via WAKE pin (>100 rpm detection) or magnetic velocity threshold. The integrated turns counter tracks ±1280 rotations with user-selectable 45° or 180° update intervals - retaining state during key-off.

Key Specifications

Pinout & Package

Package: 14-pin TSSOP (suffix LE), lead-free with 100% matte tin plating, RθJA = 82 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AMS AS5055A and Infineon TLE5012B, the A1337LLETR-P-T uniquely combines dual SPI/SENT outputs, on-chip LBIST, EEPROM-programmable 0° reference, and key-off turns counting - making it the only drop-in solution for ASIL-B-compliant EPS and PRNDL systems requiring both functional safety and production-line programmability.

Availability

A1337LLETR-P-T is available at Aetrix Electronics and suitable for electronic power steering (EPS), throttle position sensing, rotary PRNDL systems, and seatbelt pretensioner motor control requiring stable component supply across automotive production lifecycles.

Supply support for A1337LLETR-P-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 of high-performance Hall-effect sensors and power ICs, specializing in automotive-grade magnetic sensing solutions since 1989.

The A1337 product line was developed specifically for ASIL-B functional safety applications demanding redundant, contactless angular position feedback - targeting electronic power steering, transmission controls, and advanced driver assistance systems (ADAS).

FAQ

What is the operating temperature range for the A1337LLETR-P-T?

The A1337LLETR-P-T is rated for ambient temperatures from –40°C to +150°C, with maximum junction temperature of 165°C. This extended range supports under-hood placement in EPS modules and transmission control units where thermal cycling and peak engine bay temperatures occur. All electrical specifications, including angle error (±0.5° at 25°C, ±1.3° at 150°C) and low-power current (55 µA at 25°C), are guaranteed across this full range.

Does the A1337LLETR-P-T support both SPI and SENT simultaneously?

Yes, the A1337LLETR-P-T provides concurrent SPI and SENT outputs on separate pins (MISO_1/SENT_1), allowing simultaneous connection to a high-speed microcontroller (via SPI) and a safety-monitoring ECU (via SENT). Both interfaces deliver identical angle data with independent timing - enabling cross-checking for fault detection in ASIL-B systems without requiring external arbitration logic.

How is EEPROM programming performed on the A1337LLETR-P-T?

EEPROM programming on the A1337LLETR-P-T is accomplished either through the standard SPI interface or via Manchester encoding applied directly to the VCC_1 pin using 19 V pulses (8–11 ms high time). This dual-mode approach eliminates the need for dedicated programming hardware: production lines use VCC pulsing for fast end-of-line calibration, while engineering teams use SPI for development-stage parameter tuning.

What diagnostic features does the A1337LLETR-P-T include for functional safety compliance?

The A1337LLETR-P-T integrates LBIST (logic built-in self-test), full signal path diagnostics, 4-bit CRC on all SPI messages, and a user-programmable missing-magnet error flag. These features collectively support ASIL-B compliance per ISO 26262 by enabling continuous runtime verification of sensor health, communication integrity, and magnetic field presence - all accessible via SPI or SENT without external test equipment.

Can the A1337LLETR-P-T operate in low-power mode while maintaining turns-counting functionality?

Yes, the A1337LLETR-P-T maintains its ±1280-turns counter in low-power mode with configurable sleep periods (2–512 ms) and retains count state during key-off. The counter updates every 45° or 180° of magnet rotation - enabling battery-conscious applications like seatbelt pretensioner motor logging and parking brake position tracking without waking the main ECU.