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

Allegro MicroSystems A1337LLETR-DD-T

Name: A1337LLETR-DD-T
Brand: Allegro MicroSystems
SKU: A1337LLETR-DD-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: A1337LLETR-DD-T

Manufacturer:: Allegro MicroSystems

Category:: Angle, Linear Position Measuring

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

Datasheet:: A1337LLETR-DD-T.pdf

Description:: HIGH RESOLUTION PROGRAMMABLE ANG

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Product details

Overview

A1337LLETR-DD-T from Allegro MicroSystems is a dual-die, contactless 0°–360° Hall-effect angle sensor IC with independent SPI and SENT outputs per die, 12-bit resolution in low-RPM mode, ±0.5° typical angle error at 25°C, and integrated turns counter supporting –1280 to +1280 counts - deployed in electronic power steering (EPS), rotary PRNDL systems, and throttle position sensing.

For engineers reviewing the A1337LLETR-DD-T datasheet, A1337LLETR-DD-T pinout, A1337LLETR-DD-T application, or A1337LLETR-DD-T equivalent, this page delivers verified technical context on dual-SoC architecture, SENT protocol modes (SAE J2716, TSENT, SSENT, ASENT), EEPROM-programmable angle refresh rate (25–3200 µs), CVH self-test, and key automotive safety features including LBIST and 4-bit SPI CRC.

Technical Context

The A1337LLETR-DD-T integrates two electrically independent system-on-chip (SoC) dies in a single 24-pin TSSOP package, each featuring a circular vertical Hall (CVH) front end, digital signal processing, SPI (Mode 3, 10 MHz max), and SENT output. Each die operates with separate VCC_1/VCC_2, GNDA/GNDD, WAKE, and bypass pins, enabling true functional redundancy.

It supports dual operational modes: high-RPM mode (25 µs refresh, 7600 rpm max) and low-RPM mode (200–3200 µs refresh, 12-bit resolution), with programmable averaging via EEPROM. Diagnostics include user-triggered LBIST, full-signal-path monitoring, 4-bit CRC on SPI frames, and configurable missing-magnet detection.

Key Specifications

Parameter	Value and Actual Design Meaning
Angle Range	0° to 360° absolute measurement - enables full-rotation position tracking without multi-turn ambiguity.
Resolution	12-bit in low-RPM mode (≈0.088°/LSB); 10-bit in high-RPM mode - balances latency vs. precision for EPS or throttle control.
Refresh Rate	Configurable 25 µs to 3200 µs via EEPROM - allows dynamic trade-off between update speed and noise rejection.
SENT Output Modes	SAE J2716 (JAN2010), triggered (TSENT), sequential (SSENT), and addressable (ASENT) - supports flexible ECU integration and diagnostic messaging.
Turns Counter Range	–1280 to +1280 counts, update every 45° or 180° - tracks multi-turn rotation during key-off state for seatbelt motor or gear position.
Operating Temp	–40°C to +150°C ambient - qualified for under-hood automotive environments per AEC-Q100.
Supply Voltage	3.7 V to 16 V, absolute max 26.5 V - enables direct battery connection with robust reverse-battery and overvoltage protection.

Pinout & Package

Package: 24-pin TSSOP (suffix LE), lead-free with 100% matte tin plating, thermal resistance R_θJA = 117°C/W.

Pin/Terminal	Circuit Role	Design Meaning
VCC_1 / VCC_2	Independent power supply inputs (die 1 / die 2)	Enable isolated biasing; also used for Manchester-mode EEPROM programming via pulsed VCC.
SENT_1 / SENT_2	Dedicated SENT output channels (die 1 / die 2)	Support redundant SENT streams; each configurable for SAE J2716, TSENT, SSENT, or ASENT protocols.
WAKE_1 / WAKE_2	External wake-up trigger inputs (die 1 / die 2)	Automatically exit low-power mode when magnet speed >100 rpm or external voltage exceeds 215 mV threshold.
SCLK_1/ID1_1, CS_1/ID0_1, MOSI_1, MISO_1 SCLK_2/ID1_2, CS_2/ID0_2, MOSI_2, MISO_2	Dual independent SPI interfaces (die 1 / die 2)	Full-duplex Mode 3 operation up to 10 MHz; ID0/ID1 pins double as peripheral address bits for SSENT/ASENT.
BYP1_1 / BYP2_1 / BYP1_2 / BYP2_2	Internal regulator bypass terminals (die 1 / die 2)	BYP1 provides 2.7 V nominal regulated output; BYP2 enables elevated SPI output (3.1 V typ) when required.
GNDA_1 / GNDA_2 GNDD_1 / GNDD_2	Analog and digital ground returns (die 1 / die 2)	Separate analog/digital grounds per die minimize coupling noise in high-EMI automotive environments.

Key Features

Feature	Design Value
Dual independent SoCs in one package	Enables hardware-redundant angle sensing per ISO 26262 ASIL-D architectures without PCB area penalty.
Programmable low-power mode	Typical 55 µA per die at 25°C; duty-cycle configurable via EEPROM to optimize current draw in key-off state.
On-chip EEPROM with ECC	100 write cycles; stores calibration offsets, 0° reference point, rotation direction (CW/CCW), and SENT/SPI configuration.
Integrated CVH self-test	23 ms deterministic test verifying magnetic front-end integrity - eliminates need for external test fixtures.
Adjustable discontinuity point	User-definable 0° angle reference via EEPROM - accommodates mechanical misalignment or custom target geometry.
Ultralow-power transport mode	30 µA per die at 150°C - maintains storage readiness during extended vehicle off-time without battery drain.

Applications

Electronic Power Steering (EPS)	Rotary PRNDL Selector
Use Scenario: Real-time detection of steering column angular position and rotational direction for assist torque calculation and fault monitoring. IC Role / Device Role / Timing Role: Primary angle sensor providing 25 µs refresh rate in high-RPM mode during maneuvering; dual-die output enables cross-checking for ASIL-B/D compliance. Use Value: ±0.5° typical angle error and <60 µs response time ensure precise torque vectoring; SENT_1/SENT_2 support redundant ECU communication paths.	Use Scenario: Monitoring rotary switch position in automatic transmission gear selectors to determine P/R/N/D/L states. IC Role / Device Role / Timing Role: Absolute 0°–360° position encoder with programmable 0° reference; low-RPM mode (200 µs refresh) suffices for slow manual actuation. Use Value: 12-bit resolution ensures fine-grained detent discrimination; EEPROM-stored discontinuity point compensates for mechanical assembly tolerance.
Throttle Position Sensing	Seatbelt Motor Position
Use Scenario: Closed-loop feedback of throttle valve angular position for engine management and emissions control. IC Role / Device Role / Timing Role: High-accuracy, fail-operational angle sensor interfacing via SPI to main ECU and SENT to secondary safety monitor. Use Value: Dual-die architecture allows real-time comparison of SENT_1 vs SENT_2 outputs; 4-bit SPI CRC prevents corrupted command injection.	Use Scenario: Tracking multi-turn rotation of seatbelt retractor motor to detect pretensioner deployment readiness and lock status. IC Role / Device Role / Timing Role: Turns counter with –1280 to +1280 range, updating every 45°; operates in low-power mode during vehicle sleep. Use Value: Maintains position history across ignition cycles; WAKE_1 activation at >100 rpm enables immediate resumption of sampling upon belt tension event.

Electronic Power Steering (EPS)

Rotary PRNDL Selector

Use Scenario: Real-time detection of steering column angular position and rotational direction for assist torque calculation and fault monitoring.

IC Role / Device Role / Timing Role: Primary angle sensor providing 25 µs refresh rate in high-RPM mode during maneuvering; dual-die output enables cross-checking for ASIL-B/D compliance.

Use Value: ±0.5° typical angle error and <60 µs response time ensure precise torque vectoring; SENT_1/SENT_2 support redundant ECU communication paths.

Use Scenario: Monitoring rotary switch position in automatic transmission gear selectors to determine P/R/N/D/L states.

IC Role / Device Role / Timing Role: Absolute 0°–360° position encoder with programmable 0° reference; low-RPM mode (200 µs refresh) suffices for slow manual actuation.

Use Value: 12-bit resolution ensures fine-grained detent discrimination; EEPROM-stored discontinuity point compensates for mechanical assembly tolerance.

Throttle Position Sensing

Seatbelt Motor Position

Use Scenario: Closed-loop feedback of throttle valve angular position for engine management and emissions control.

IC Role / Device Role / Timing Role: High-accuracy, fail-operational angle sensor interfacing via SPI to main ECU and SENT to secondary safety monitor.

Use Value: Dual-die architecture allows real-time comparison of SENT_1 vs SENT_2 outputs; 4-bit SPI CRC prevents corrupted command injection.

Use Scenario: Tracking multi-turn rotation of seatbelt retractor motor to detect pretensioner deployment readiness and lock status.

IC Role / Device Role / Timing Role: Turns counter with –1280 to +1280 range, updating every 45°; operates in low-power mode during vehicle sleep.

Use Value: Maintains position history across ignition cycles; WAKE_1 activation at >100 rpm enables immediate resumption of sampling upon belt tension event.

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, 14-bit resolution, I²C-only interface, no SENT output, no integrated turns counter	Lacks dual-output redundancy and automotive SENT compatibility; suited for non-safety-critical industrial encoders	Select only if SENT interface and ASIL-compliant redundancy are not required; verify external diagnostics coverage.
Infineon TLE5012B	Single-die, 16-bit resolution, BISS-C and PWM outputs, no EEPROM, no WAKE pin, 125°C max ambient	Missing key automotive features: no SENT, no key-off turns counting, lower temperature rating limits under-hood use	Consider only for cost-sensitive, non-safety-critical applications below 125°C; requires external wake logic.

Compared with AMS AS5055A and Infineon TLE5012B, the A1337LLETR-DD-T uniquely delivers dual-SoC redundancy, SENT protocol flexibility (including ASENT), EEPROM-programmable 0° reference and turns counter, and full AEC-Q100 qualification to 150°C - making it the only option meeting ASIL-D-ready requirements for EPS and PRNDL systems.

Availability

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

Supply support for A1337LLETR-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 of high-performance magnetic sensors and power ICs, specializing in automotive-grade motion sensing and current measurement solutions since 1989.

The A1337 product line was developed specifically for safety-critical automotive angle sensing, integrating dual-die redundancy, SENT/SPI dual-interface flexibility, and on-chip diagnostics to meet ISO 26262 requirements for EPS, transmission, and chassis control systems.

FAQ

What distinguishes A1337LLETR-DD-T from the single-die A1337LLETR-T?

The A1337LLETR-DD-T contains two fully independent SoC dies in a 24-pin TSSOP package, each with dedicated VCC, ground, SENT, SPI, and WAKE pins - enabling true hardware redundancy. In contrast, the A1337LLETR-T is a single-die 14-pin device with shared resources. The dual-die architecture of A1337LLETR-DD-T supports ASIL-D decomposition by allowing cross-die validation of angle data and independent diagnostic execution, which is essential for EPS and PRNDL safety systems.

Does A1337LLETR-DD-T support SAE J2716 SENT protocol out of the box?

Yes, the A1337LLETR-DD-T natively supports SAE J2716 (JAN2010) SENT protocol on both SENT_1 and SENT_2 outputs. It also offers three Allegro-proprietary extensions: triggered SENT (TSENT), sequential SENT (SSENT), and addressable SENT (ASENT). All modes are selectable via EEPROM configuration; no external protocol translator or firmware modification is required to implement standard J2716 messaging.

How does the turns counter in A1337LLETR-DD-T operate during vehicle key-off?

The A1337LLETR-DD-T turns counter remains active in low-power mode during key-off, tracking magnet rotation in CW/CCW direction across –1280 to +1280 counts. It updates every 45° or 180° (user-selectable via EEPROM), drawing only 55 µA per die at 25°C. WAKE_1 or WAKE_2 can force immediate wake-up when rotational speed exceeds 100 rpm, ensuring no position loss during unexpected belt tension or gear movement.

Can A1337LLETR-DD-T be programmed without dedicated programming hardware?

Yes, the A1337LLETR-DD-T supports Manchester encoding-based programming directly on the VCC line - eliminating need for SPI-only programmers. A precise 19 V pulse (8–11 ms high time, 300 µs rise, 60 µs fall) applied to VCC initiates Manchester mode, allowing end-of-line calibration, 0° reference setting, SENT mode selection, and averaging configuration using only the power rail and a microcontroller GPIO. This reduces factory test complexity and fixture cost.

What diagnostic capabilities does A1337LLETR-DD-T provide for ISO 26262 compliance?

The A1337LLETR-DD-T includes user-controlled logic built-in self-test (LBIST), full-signal-path diagnostics, 4-bit CRC on all SPI transactions, and configurable missing-magnet detection flags. LBIST achieves >70% fault coverage in ≤10 ms and can be triggered via SPI or SENT. These features enable systematic diagnostic coverage required for ASIL-B and ASIL-D decomposition - verified in Allegro's AEC-Q100 qualification and documented in the Functional Safety Manual for A1337.

A1337LLETR-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:: Active

Programmable:: -

For Measuring:: -

Technology:: -

Rotation Angle - Electrical, Mechanical:: -

Linear Range:: -

Output:: -

Output Signal:: -

Actuator Type:: -

Linearity:: -

Resistance:: -

Resistance Tolerance:: -

Voltage - Supply:: -

Mounting Type:: Surface Mount

Termination Style:: Gull Wing

Operating Temperature:: -

Grade:: -

Qualification:: -

Supplier Device Package:: 24-TSSOP

A1337LLETR-DD-T FAQ

1.How can I place an order for A1337LLETR-DD-T through Aetrix?

Please submit a Request for Quotation (RFQ) for A1337LLETR-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 A1337LLETR-DD-T reliable?

The price and inventory of A1337LLETR-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 A1337LLETR-DD-T is usually 5 days.

3.What payment methods are accepted for A1337LLETR-DD-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A1337LLETR-DD-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for A1337LLETR-DD-T?

A1337LLETR-DD-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your A1337LLETR-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 A1337LLETR-DD-T?

For technical support, including A1337LLETR-DD-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A1337LLETR-DD-T requirements.

6.How does Aetrix verify that A1337LLETR-DD-T is sourced from the original manufacturer or authorized distributors?

All A1337LLETR-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 A1337LLETR-DD-T meets industry standards.

7.What is the process for return or replacement of A1337LLETR-DD-T?

All A1337LLETR-DD-T units undergo pre-shipment inspection (PSI). If there is an issue with A1337LLETR-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 A1337LLETR-DD-T part is unused and in its original packaging.

Return procedure for A1337LLETR-DD-T:

1.Submit a request within 90 days.

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

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