Allegro MicroSystems A1339LLETR-5-T

Overview

A1339LLETR-5-T from Allegro MicroSystems is a single-die, 360° contactless Hall-effect angle sensor IC for automotive safety-critical systems. It delivers 12-/15-bit angular position data via ABI/UVW or PWM outputs, supports 5 V supply operation, operates from –40°C to 150°C, and meets ASIL B requirements when integrated per the safety manual. It is used in electronic power steering (EPS), rotary PRNDLs, and throttle position sensing.

For engineers reviewing the A1339LLETR-5-T datasheet, A1339LLETR-5-T pinout, A1339LLETR-5-T application, or A1339LLETR-5-T equivalent, key selection criteria include its 14-pin TSSOP package, 5 V interface compatibility, 7 µs angular response time, on-chip EEPROM programmability, and integrated diagnostics for ISO 26262-compliant system design.

Technical Context

The A1339LLETR-5-T implements dual digital signal paths: a high-speed PLL-based main path for low-latency angle measurement and a ZCD-based secondary path for turns counting and diagnostics. Its circular vertical Hall (CVH) front end enables robust operation across wide air gaps with field strengths up to 1200 G.

It integrates SPI (up to 10 MHz), PWM (98 Hz–3.125 kHz), and configurable ABI/UVW outputs-all programmable via on-chip EEPROM supporting 100 write cycles. Diagnostics include logic BIST, signal-path monitoring, watchdog timers, and 4-bit CRC on SPI transactions.

Key Specifications

Pinout & Package

Package: 14-pin TSSOP (suffix LE), exposed pad not present; RoHS-compliant, 100% matte tin leadframe plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AMS AS5055A-BQFT and Infineon TLE5012BE1000, the A1339LLETR-5-T uniquely balances ASIL B compliance, 14-pin TSSOP compactness, and native ABI/UVW/PWM output flexibility-enabling drop-in replacement in existing EPS and PRNDL designs without MCU firmware changes or board rework.

Availability

A1339LLETR-5-T is available at Aetrix Electronics and suitable for electronic power steering (EPS), rotary PRNDL selectors, and throttle position sensing requiring stable component supply across automotive production lifecycles.

Supply support for A1339LLETR-5-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, headquartered in Manchester, NH.

The A1339 product line delivers precision, safety-certified angle sensing for automotive motion control-designed specifically to replace potentiometers and resolver-based systems in EPS, transmission, and braking applications.

FAQ

What is the operating supply voltage range for the A1339LLETR-5-T?

The A1339LLETR-5-T operates from 4.0 V to 16.5 V, supporting direct 12 V battery connection and transient immunity per ISO 7637-2 Pulse 5b up to 39 V. Its 5 V interface mode is enabled when VCC ≥ 5 V, configuring digital I/O thresholds accordingly. This wide range ensures robust performance in automotive environments where battery voltage fluctuates significantly during cranking and load dump events. The A1339LLETR-5-T maintains specified accuracy and diagnostics functionality across this entire range.

Does the A1339LLETR-5-T support both ABI encoder and UVW motor commutation outputs?

Yes, the A1339LLETR-5-T supports both output formats on pins A/U, B/V, and I/W. Configuration is stored in on-chip EEPROM and selectable per application: ABI provides quadrature signals with programmable resolution (1–2048 PPR) and hysteresis (0–1.38°); UVW delivers three-phase commutation signals with programmable pole-pair count (1–16). Both modes operate simultaneously with <7 µs latency. The A1339LLETR-5-T does not require external logic to switch between them-configuration is retained across power cycles.

How does the A1339LLETR-5-T achieve ASIL B compliance?

The A1339LLETR-5-T achieves ASIL B compliance as a safety element out-of-context (SEooC) developed per ISO 26262 Part 5. It includes logic BIST, CVH self-test, ECC-protected EEPROM, 4-bit SPI CRC, and configurable diagnostic flags. Compliance requires integration per the A1339 Safety Manual-including correct configuration of diagnostics, fault response timing, and system-level redundancy. The A1339LLETR-5-T itself is not certified standalone; its ASIL B claim is valid only when used as specified in the safety manual with appropriate system-level controls.

Can the A1339LLETR-5-T retain absolute position during vehicle power-off?

Yes, the A1339LLETR-5-T supports absolute position retention during vehicle power-off via its low-power mode and turns counter. In low-power mode, it consumes just 98 µA (typical) while continuously monitoring magnetic field changes and updating turns count. Upon wake-up-triggered by field change or external WAKE signal-it reports full 360° angle plus accumulated turns. This eliminates the need for homing routines after ignition restart. The A1339LLETR-5-T stores critical parameters in EEPROM to ensure consistent behavior across sleep/wake cycles.

What is the maximum SPI clock frequency supported by the A1339LLETR-5-T?

The A1339LLETR-5-T supports SPI clock frequencies up to 10 MHz, enabling low-latency access to 12-/15-bit angle data, diagnostic registers, and configuration memory. Timing requirements include 40–60% duty cycle, 25 ns MOSI setup time, and 30 ns data valid window after SCLK falling edge. The interface supports daisy-chaining multiple A1339LLETR-5-T devices on a shared bus using individual CS lines. All SPI transactions include 4-bit CRC for error detection-critical for functional safety applications.