Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Sensors, Transducers > Position Sensors > Angle, Linear Position Measuring

Allegro MicroSystems A1338LLETR-DD-T

Name: A1338LLETR-DD-T
Brand: Allegro MicroSystems
SKU: A1338LLETR-DD-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: A1338LLETR-DD-T

Manufacturer:: Allegro MicroSystems

Category:: Angle, Linear Position Measuring

Package:: 24-TSSOP (0.173", 4.40mm Width)

Datasheet:: A1338LLETR-DD-T.pdf

Description:: SENSOR ANGLE 360DEG SOLDER TAB

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,571

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

A1338LLETR-DD-T from Allegro MicroSystems is a dual-die, contactless 0° to 360° Hall-effect angle sensor IC with SPI and SENT outputs, 12-bit resolution in Low RPM mode, 25 µs angle refresh rate in High RPM mode, and integrated EEPROM for end-of-line calibration-designed for automotive electronic power steering (EPS) and rotary PRNDL systems.

For engineers reviewing the A1338LLETR-DD-T datasheet, A1338LLETR-DD-T pinout, A1338LLETR-DD-T application, or A1338LLETR-DD-T equivalent, this page delivers verified technical context, dual-SoC pin mapping, SENT protocol compliance (SAE J2716 JAN2010), diagnostics coverage, and real-world selection guidance for safety-critical angular sensing.

Technical Context

The A1338LLETR-DD-T integrates two independent system-on-chip (SoC) die in a single 24-pin TSSOP package, each featuring Circular Vertical Hall (CVH) front ends, digital signal processing, 4-bit CRC SPI interface, and SENT output with SAE J2716 compatibility. It supports programmable averaging (AVG[2:0]) and dual-mode operation: Low RPM (up to 128-sample averaging, 200 µs refresh) and High RPM (25 µs refresh, 10-bit effective resolution).

Diagnostics include user-controlled logic built-in self-test (LBIST), full signal path validation, and EEPROM-configurable Missing Magnet Error flag. Its absolute maximum VCC is 26.5 V, operating ambient range is –40°C to +150°C, and it delivers <0.5° angle error at 25°C with ideal magnet alignment and 300 G field strength.

Key Specifications

Parameter	Value and Actual Design Meaning
Angle Range	0° to 360° absolute measurement via CVH technology-enables full-rotation position feedback without mechanical stops.
Output Protocols	SPI (Mode 3, 4-bit CRC) and SENT (SAE J2716 JAN2010, TSENT, SSENT, ASENT)-supports redundant communication in ASIL-B/C systems.
Resolution	12-bit in Low RPM mode (8–12-bit effective depending on field strength); 10-bit in High RPM mode-directly maps to 0.0879°/LSB and 0.3516°/LSB quantization steps.
Refresh Rate	Configurable 25–3200 µs via EEPROM-25 µs enables 40 kHz bandwidth for high-speed EPS motor control loops.
Max Sensing Speed	7600 rpm with full accuracy; up to 30,000 rpm with reduced accuracy-validates use in high-RPM throttle and turbocharger applications.
EEPROM Endurance	100 read/write cycles with ECC error correction-supports factory calibration, zero-angle offset, and rotation direction (CW/CCW) programming.
Supply Voltage	3.7 V to 16 V nominal; 26.5 V absolute max-allows direct connection to automotive battery with reverse-battery protection down to –18 V.

Pinout & Package

Package: 24-pin TSSOP (Suffix LE), lead-free with 100% matte-tin plating, thermal resistance R_θJA = 82 °C/W.

Pin/Terminal	Circuit Role	Design Meaning
BYP1_1, BYP2_1 BYP1_2, BYP2_2	External bypass capacitor terminals (die 1 & die 2)	Stabilize internal regulators; BYP1 pins deliver ~2.7 V (±0.2 V), BYP2 pins support elevated SPI output voltage (2.9–3.3 V) when enabled.
CS_1/ID0_1, CS_2/ID0_2	SPI chip select / SENT address bit 0	Active-low enable for SPI transactions; also encodes peripheral ID for SSENT/ASENT modes-enables multi-sensor daisy-chaining.
SCLK_1/ID1_1, SCLK_2/ID1_2	SPI clock / SENT address bit 1	Drives synchronous data transfer; dual ID bits allow unique addressing of both SoCs in SENT networks without external logic.
MISO_1, MISO_2 MOSI_1, MOSI_2	SPI data I/O (die 1 & die 2)	Full-duplex communication per die; supports independent configuration and readback-critical for redundancy validation in safety systems.
SENT_1/PWM_1, SENT_2/PWM_2	SENT output (die 1 & die 2)	Dedicated SENT channels compliant with SAE J2716; no PWM function on A1338LLETR-DD-T-ensures deterministic timing for diagnostic message framing.
VCC_1, VCC_2 GNDD_1, GNDD_2 GNDA_1, GNDA_2	Power and ground (die 1 & die 2)	Independent power domains isolate noise between SoCs; dual analog/digital grounds reduce crosstalk in high-EMI automotive environments.
BIAS_1, BIAS_2	Bias reference configuration	Connect to GND or 3.3 V to set magnetic field sensitivity and offset-enables tuning for specific magnet geometries and air gaps.

Key Features

Feature	Design Value
Dual independent SoCs in one package	Enables hardware-redundant angle sensing per ISO 26262 without board-level duplication-reduces PCB area and interconnect complexity vs. discrete dual-sensor solutions.
SENT protocol with four modes	Supports SAE J2716 standard plus Allegro proprietary TSENT/SSENT/ASENT-allows flexible integration into legacy and next-gen automotive networks with configurable message scheduling.
User-controlled LBIST and signal path diagnostics	Validates internal logic and analog chain integrity on-demand via SPI/SENT-meets ASIL-B diagnostic coverage requirements without external test equipment.
Programmable discontinuity point (0° angle)	Allows field-specific zero-angle definition during end-of-line calibration-eliminates mechanical alignment tolerances in PRNDL or seatbelt motor assemblies.
Manchester encoding on VCC line	Enables EEPROM programming with only three wires (VCC, GND, SENT)-reduces test fixture cost and simplifies production calibration in constrained space applications.

Applications

Electronic Power Steering (EPS)	Rotary PRNDL Selector
Use Scenario: Real-time detection of steering column rotation angle for assist torque calculation and lane-keeping feedback. IC Role / Device Role / Timing Role: Primary angle sensor providing 25 µs refreshed 12-bit angle data over SENT to EPS ECU; dual-SoC architecture supports cross-checking for ASIL-D fault detection. Use Value: Enables <0.5° angular error at 25°C and <1.3° drift at 150°C-meeting tight closed-loop control requirements while supporting 7600 rpm peak shaft speeds.	Use Scenario: Accurate gear position identification in rotary transmission selectors with tactile feedback and automatic parking engagement. IC Role / Device Role / Timing Role: Absolute 0°–360° position encoder delivering SENT messages synchronized to vehicle CAN bus timing; programmable 0° reference aligns with mechanical detent positions. Use Value: Eliminates potentiometer wear and contact bounce; 100-cycle EEPROM endurance allows field updates to zero-point calibration after assembly or service.
Seatbelt Pretensioner Motor	Throttle Actuator Feedback
Use Scenario: Monitoring spool rotation in pyrotechnic seatbelt pretensioners to confirm deployment completion and prevent false retraction. IC Role / Device Role / Timing Role: Safety-critical angle monitor using LBIST and missing-magnet diagnostics to validate sensor health before and during deployment event. Use Value: Dual-SoC independence ensures functional redundancy; SENT output provides deterministic latency (<1 ms frame duration) for time-triggered safety protocols.	Use Scenario: Closed-loop position control of electronic throttle bodies under high-vibration, wide-temperature engine bay conditions. IC Role / Device Role / Timing Role: High-bandwidth angular feedback device operating in High RPM mode (25 µs refresh) with SENT output synchronized to engine control cycle. Use Value: Maintains <0.55° angle noise at 150°C and ±1.4° temperature drift-supporting precise airflow regulation across –40°C to +150°C ambient range.

Electronic Power Steering (EPS)

Rotary PRNDL Selector

Use Scenario: Real-time detection of steering column rotation angle for assist torque calculation and lane-keeping feedback.

IC Role / Device Role / Timing Role: Primary angle sensor providing 25 µs refreshed 12-bit angle data over SENT to EPS ECU; dual-SoC architecture supports cross-checking for ASIL-D fault detection.

Use Value: Enables <0.5° angular error at 25°C and <1.3° drift at 150°C-meeting tight closed-loop control requirements while supporting 7600 rpm peak shaft speeds.

Use Scenario: Accurate gear position identification in rotary transmission selectors with tactile feedback and automatic parking engagement.

IC Role / Device Role / Timing Role: Absolute 0°–360° position encoder delivering SENT messages synchronized to vehicle CAN bus timing; programmable 0° reference aligns with mechanical detent positions.

Use Value: Eliminates potentiometer wear and contact bounce; 100-cycle EEPROM endurance allows field updates to zero-point calibration after assembly or service.

Seatbelt Pretensioner Motor

Throttle Actuator Feedback

Use Scenario: Monitoring spool rotation in pyrotechnic seatbelt pretensioners to confirm deployment completion and prevent false retraction.

IC Role / Device Role / Timing Role: Safety-critical angle monitor using LBIST and missing-magnet diagnostics to validate sensor health before and during deployment event.

Use Value: Dual-SoC independence ensures functional redundancy; SENT output provides deterministic latency (<1 ms frame duration) for time-triggered safety protocols.

Use Scenario: Closed-loop position control of electronic throttle bodies under high-vibration, wide-temperature engine bay conditions.

IC Role / Device Role / Timing Role: High-bandwidth angular feedback device operating in High RPM mode (25 µs refresh) with SENT output synchronized to engine control cycle.

Use Value: Maintains <0.55° angle noise at 150°C and ±1.4° temperature drift-supporting precise airflow regulation across –40°C to +150°C ambient range.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AMS AS5055A	Single-die 12-bit Hall angle sensor with SPI/I²C; no SENT output; max 10,000 rpm; no LBIST or EEPROM-based diagnostics.	Lacks dual-SoC redundancy and SENT protocol-suitable for non-safety-critical industrial encoders but not ASIL-B automotive systems.	Select only if SENT interface and functional safety diagnostics are not required; verify magnetic field tolerance (±1000 G vs. A1338LLETR-DD-T's ±1500 G).
Infineon TLE5012B	Single-die 14-bit angle sensor with BISS-C, SPI, and SENT; includes on-chip temperature compensation; no dual-die package option.	Offers higher resolution but no hardware-redundant die pair-requires external dual-sensor layout for ASIL-D compliance.	Prefer when >12-bit resolution is mandatory and board space permits separate sensors; confirm SENT timing compliance with SAE J2716 JAN2010 revision.

Compared with AMS AS5055A and Infineon TLE5012B, the A1338LLETR-DD-T uniquely delivers certified dual-SoC redundancy in one package, SENT protocol flexibility, and production-ready EEPROM diagnostics-making it the only choice for space-constrained, ASIL-B/C automotive angle sensing where board-level duplication is impractical.

Availability

A1338LLETR-DD-T is available at Aetrix Electronics and suitable for electronic power steering (EPS), rotary PRNDL selectors, seatbelt pretensioner motors, and throttle actuator feedback systems requiring stable component supply, automotive-grade qualification, and long-term lifecycle continuity.

Supply support for A1338LLETR-DD-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 Hall-effect sensors, motor drivers, and power ICs, serving automotive, industrial, and consumer markets since 1989.

The A1338 product line was developed specifically for ASIL-B/C automotive angle sensing applications-including EPS, transmission controls, and safety restraint systems-emphasizing dual-die redundancy, SENT protocol compliance, and end-of-line programmability.

FAQ

What is the primary function of the A1338LLETR-DD-T in automotive systems?

The A1338LLETR-DD-T serves as a dual-die, contactless 0° to 360° Hall-effect angle sensor IC that delivers high-resolution angular position data via SPI and SENT interfaces. Its core function is to provide deterministic, safety-certifiable feedback for closed-loop control in electronic power steering, rotary PRNDL selectors, and throttle actuators-leveraging two independent SoCs to meet ASIL-B/C diagnostic coverage requirements without external redundancy circuitry. The A1338LLETR-DD-T achieves this through integrated CVH sensing, on-chip EEPROM calibration, and programmable diagnostics.

Does the A1338LLETR-DD-T support both SENT and PWM output simultaneously?

No, the A1338LLETR-DD-T supports SPI and SENT outputs only-PWM functionality is exclusive to the A1338LLETR-P-T variant. The "-DD-T" suffix explicitly denotes dual-die configuration with SENT output, and the datasheet confirms SENT_1/PWM_1 and SENT_2/PWM_2 pins operate exclusively in SENT mode for this part number. Attempting to configure PWM on A1338LLETR-DD-T will not yield valid output, as the internal firmware and pin logic are fixed for SENT protocol compliance per SAE J2716 JAN2010 and Allegro proprietary modes (TSENT/SSENT/ASENT). The A1338LLETR-DD-T does not contain PWM generation circuitry.

How does the dual-die architecture of the A1338LLETR-DD-T improve functional safety?

The dual-die architecture of the A1338LLETR-DD-T enables hardware-level redundancy by integrating two electrically independent SoCs in one 24-pin TSSOP package-each with its own CVH sensor, signal chain, EEPROM, and SENT output. This allows cross-comparison of angle readings, independent LBIST execution, and fault isolation without shared failure modes. In ASIL-B/C systems, it satisfies diagnostic coverage requirements for random hardware failures by eliminating single points of failure present in single-die solutions. The A1338LLETR-DD-T leverages this architecture to support safe torque intervention and fail-operational behavior in EPS and transmission control, where continuous angle validity is mandated. Each die operates autonomously, and the A1338LLETR-DD-T datasheet specifies separate power, ground, and communication paths to ensure true independence.

What is the maximum rotational speed the A1338LLETR-DD-T can measure with full accuracy?

The A1338LLETR-DD-T measures rotational speed with full accuracy up to 7600 rpm, as confirmed in the "Features and Benefits" section and Operating Characteristics table. Beyond this speed, angle data remains available up to 30,000 rpm but with proportionally reduced accuracy due to signal path latency and angular lag effects. The datasheet quantifies this lag using the formula Angle_Lag = (rpm × 6) / (16 × tRESPONSE), where tRESPONSE is 60 µs in Low RPM mode. At 7600 rpm, lag is approximately 1.8°-within the specified ±0.5° total angle error at 25°C. For applications exceeding 7600 rpm, users must apply external velocity-based compensation or accept degraded precision. The A1338LLETR-DD-T's 25 µs refresh rate in High RPM mode supports this performance ceiling.

Can the A1338LLETR-DD-T be programmed after soldering onto a PCB?

Yes, the A1338LLETR-DD-T supports post-soldering EEPROM programming via Manchester encoding on the VCC line-requiring only VCC, GND, and SENT pins, with no additional programming headers or debug interfaces. This method uses 18–19.5 V pulses on VCC (tPULSE(H) = 8–11 ms, separation ≥2 µs) to enter programming mode, enabling end-of-line calibration of zero-angle offset, rotation direction (CW/CCW), and averaging settings. The A1338LLETR-DD-T's EEPROM includes ECC error correction and supports 100 write cycles, making it suitable for final calibration in automated test fixtures. However, care must be taken to avoid voltage transients affecting other devices sharing the same VCC rail during programming.

A1338LLETR-DD-T Specifications

Product attributes: Attribute value

Manufacturer:: Allegro MicroSystems

Package/Case:: 24-TSSOP (0.173", 4.40mm Width)

Series:: -

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Programmable:: -

For Measuring:: Angle

Technology:: Hall Effect

Rotation Angle - Electrical, Mechanical:: 0° ~ 360°, Continuous

Linear Range:: -

Output:: SENT, SPI

Output Signal:: Programmable

Actuator Type:: External Magnet, Not Included

Linearity:: -

Resistance:: -

Resistance Tolerance:: -

Voltage - Supply:: 3.7V ~ 18V

Mounting Type:: Surface Mount

Termination Style:: Gull Wing

Operating Temperature:: -40°C ~ 150°C (TA)

Grade:: -

Qualification:: -

Supplier Device Package:: 24-TSSOP

A1338LLETR-DD-T FAQ

1.How can I place an order for A1338LLETR-DD-T through Aetrix?

Please submit a Request for Quotation (RFQ) for A1338LLETR-DD-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for A1338LLETR-DD-T reliable?

The price and inventory of A1338LLETR-DD-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A1338LLETR-DD-T is usually 5 days.

3.What payment methods are accepted for A1338LLETR-DD-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A1338LLETR-DD-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for A1338LLETR-DD-T?

A1338LLETR-DD-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your A1338LLETR-DD-T order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for A1338LLETR-DD-T?

For technical support, including A1338LLETR-DD-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A1338LLETR-DD-T requirements.

6.How does Aetrix verify that A1338LLETR-DD-T is sourced from the original manufacturer or authorized distributors?

All A1338LLETR-DD-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that A1338LLETR-DD-T meets industry standards.

7.What is the process for return or replacement of A1338LLETR-DD-T?

All A1338LLETR-DD-T units undergo pre-shipment inspection (PSI). If there is an issue with A1338LLETR-DD-T, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The A1338LLETR-DD-T part is unused and in its original packaging.

Return procedure for A1338LLETR-DD-T:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…