My Inquiry
My Account
Allegro MicroSystems A1338LLETR-P-T
- Part No.:
- A1338LLETR-P-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Angle, Linear Position Measuring
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
A1338LLETR-P-T.pdf
- Description:
- SENSOR ANGLE 360DEG SMD
- Quantity:
- Payment:
- Shipping:
Inventory:3,234
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
A1338LLETR-P-T from Allegro MicroSystems is a precision 0° to 360° Hall-effect angle sensor IC with SPI interface and PWM output, built on Circular Vertical Hall (CVH) technology. It delivers 12-bit resolution in Low RPM mode, 25 µs refresh rate in High RPM mode, and supports automotive-grade operation from –40°C to +150°C. It is used for contactless angular position sensing in electronic power steering (EPS) and throttle systems.
For engineers reviewing the A1338LLETR-P-T datasheet, A1338LLETR-P-T pinout, A1338LLETR-P-T application, or A1338LLETR-P-T equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, safety-critical diagnostics support, and two confirmed alternative parts for functional substitution in automotive motion control systems.
Technical Context
The A1338LLETR-P-T integrates a single CVH front-end die with digital signal processing, on-chip EEPROM (100-cycle endurance, ECC), and dual-output capability: SPI (Mode 3, 4-bit CRC) and programmable PWM (not SENT). Its SoC architecture enables user-controlled LBIST, full-signal-path diagnostics, and Manchester-encoded programming via VCC.
It operates in two configurable modes: Low RPM mode (up to 12-bit resolution, 200–3200 µs refresh) and High RPM mode (10-bit resolution, 25 µs refresh, up to 7600 rpm sensing). Angular latency is fixed at 60 µs in Low RPM mode, enabling deterministic error compensation in closed-loop motor control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Angle Range | 0° to 360° absolute measurement - enables full-rotation feedback without homing or multi-turn tracking logic. |
| Output Interface | SPI (Mode 3, 4-bit CRC) + PWM only - no SENT; PWM duty cycle maps linearly from 5% (0°) to 95% (360°), with tristate error signaling. |
| Resolution | 12-bit in Low RPM mode - yields 0.0879°/LSB; effective resolution ≥11.59 bits at B = 300 G, TA = 25°C. |
| Refresh Rate | Configurable 25 µs (High RPM) to 3200 µs (Low RPM) - set via EEPROM averaging bits (AVG[2:0]), directly impacts control loop bandwidth. |
| Operating Temp | –40°C to +150°C ambient - qualified per AEC-Q100 Grade 0, suitable for under-hood EPS and transmission actuator mounting. |
| Supply Voltage | 3.7 V to 16 V - supports direct connection to 12 V automotive battery with undervoltage lockout (VUVLOHI = 3.6 V). |
| Angle Accuracy | ±0.5° typical at 25°C, ±1.3° max at 150°C - specified under ideal magnet alignment and 300 G field, critical for torque estimation fidelity. |
Pinout & Package
Package: 14-pin TSSOP (Suffix LE), lead-free, 100% matte-tin plating. Thermal resistance RθJA = 82°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (BYP1_1) | Regulator bypass capacitor terminal (die 1) | Connects to 0.1 µF capacitor; stabilizes internal LDO output at 2.7 V typical - required for stable SPI/PWM timing. |
| 4 (SENT_1/PWM_1) | PWM output (die 1) | Open-drain FET output; drives 5–50 kΩ pull-up; high-state voltage depends on Rpullup (0.7×VS to 0.9×VS); tristates on unmasked errors. |
| 5 (VCC_1) | Power supply & EEPROM programming line (die 1) | Accepts 3.7–16 V; pulses at 18–19.5 V for Manchester programming - must be isolated during EEPROM write to avoid affecting other devices. |
| 8 (BIAS_1) | Bias reference control (die 1) | Configures rotation direction (CW/CCW) and zero-angle discontinuity point; tie to GND or 3.3 V - sets magnetic polarity interpretation. |
| 10 (MISO_1) | SPI data output (die 1) | Provides angle register reads, diagnostic status, and EEPROM contents; VOH = 2.7 V typical with 0.1 µF BYP1 - ensures noise margin in noisy automotive environments. |
| 11 (SCLK_1/ID1_1) | SPI clock input / SENT address bit (die 1) | Accepts 0.1–10 MHz clock; unused in PWM-only variant - remains functional for SPI configuration and diagnostics. |
| 12 (MOSI_1) | SPI data input (die 1) | Writes to EEPROM, configures averaging mode, disables error masks - essential for end-of-line calibration and safety validation. |
| 13 (CS_1/ID0_1) | SPI chip select / SENT address bit (die 1) | Active-low enable for SPI transactions; floating or pulled low disables SPI - allows shared bus operation with other sensors. |
Key Features
| Feature | Design Value |
|---|---|
| CVH-based single-channel sensing | Air-gap-independent 0°–360° measurement - eliminates mechanical wear and tolerance stack-up in EPS gearmotor assemblies. |
| User-controlled LBIST + full-signal-path diagnostics | Enables ASIL-B compliance via on-demand self-test (23 ms duration) and CRC-protected SPI - satisfies ISO 26262 diagnostic coverage requirements. |
| EEPROM with ECC and 100-cycle endurance | Stores calibrated zero-angle offset, rotation direction, and averaging mode - survives vehicle lifetime reprogramming during service or recalibration. |
| Programmable PWM carrier frequency | Three selectable frequencies (122 Hz / 1.024 kHz / 2.048 kHz) - allows EMI optimization in proximity to CAN or LIN buses. |
| Angular latency compensation support | Fixed 60 µs response time in Low RPM mode - enables deterministic lag correction in motor controllers using known RPM feedback. |
Applications
| Electronic Power Steering (EPS) | Throttle Actuator Position Feedback |
|---|---|
Use Scenario: Real-time detection of steering column rotation angle for assist torque calculation and lane-keeping assist. IC Role / Device Role / Timing Role: Primary angle sensor providing 25 µs–3200 µs configurable update rate; SPI used for calibration, PWM for fail-operational redundancy. Use Value: ±0.5° accuracy at 25°C ensures <1.5 Nm torque estimation error in 12 V EPS systems; 150°C rating permits placement near motor windings. |
Use Scenario: Closed-loop position control of drive-by-wire throttle plate with fault detection. IC Role / Device Role / Timing Role: Absolute 0°–360° angle monitor feeding PID controller; PWM output provides analog-compatible interface for legacy ECU ADC inputs. Use Value: Tristate PWM error signaling (e.g., missing magnet, LBIST failure) enables immediate limp-home mode activation without software polling. |
| Seatbelt Pretensioner Motor Control | Rotary PRNDL Selector Feedback |
Use Scenario: Monitoring spool rotation in pyrotechnic seatbelt pretensioners to verify deployment completion. IC Role / Device Role / Timing Role: Safety-critical angle verifier; LBIST executed at power-on and periodically during standby; EEPROM stores deployment history. Use Value: AEC-Q100 Grade 0 qualification and 165°C junction limit ensure reliability during airbag event thermal transients. |
Use Scenario: Gear-position encoding in rotary park/neutral/drive/low selector switches for automatic transmissions. IC Role / Device Role / Timing Role: Contactless replacement for potentiometers; PWM output interfaces directly with transmission control module's analog input channel. Use Value: 12-bit resolution enables 4096 distinct detent positions; air-gap independence tolerates housing deformation over 15-year vehicle life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar angle sensing applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AS5048A-ASSMT | 14-bit SPI-only output; no PWM; uses standard Hall array (not CVH); max 85°C ambient rating. | Lacks automotive temperature range and PWM fail-safe signaling; requires external ADC for analog-like interface. | Select only for non-automotive industrial encoders where cost > safety compliance. |
| TLE5012BE1500 | 16-bit resolution; dual SPI + SENT; includes integrated magnetic concentrator; supports 175°C junction temp. | Higher resolution but larger 16-pin HTSSOP package; SENT output incompatible with PWM-reliant ECUs. | Prefer when system requires SENT diagnostics or >12-bit resolution; verify PCB layout supports larger footprint. |
Compared with AS5048A-ASSMT and TLE5012BE1500, the A1338LLETR-P-T uniquely balances automotive-grade robustness (–40°C to +150°C), integrated PWM fail-signaling, and CVH-based air-gap stability - making it optimal for cost-constrained EPS and throttle modules requiring ASIL-B support without SENT infrastructure.
Availability
A1338LLETR-P-T is available at Aetrix Electronics and suitable for electronic power steering (EPS), throttle actuation, seatbelt pretensioner control, and rotary PRNDL feedback requiring stable component supply across automotive production lifecycles.
Supply support for A1338LLETR-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 designs high-performance magnetic sensing and power ICs for automotive and industrial motion control, headquartered in Manchester, NH, USA.
The A1338 product line delivers contactless angle sensing for safety-critical automotive subsystems, emphasizing ASIL-B readiness, field-programmable calibration, and dual-output flexibility (SPI + PWM/SENT) to meet diverse ECU interface requirements.
FAQ
What output protocols does the A1338LLETR-P-T support?
The A1338LLETR-P-T supports SPI (Mode 3, 4-bit CRC) and PWM outputs only - it does not support SENT. The PWM output delivers duty cycle proportional to measured angle (5% = 0°, 95% = 360°), with tristate behavior during unmasked errors. SPI is used for configuration, diagnostics, and reading raw angle registers. This dual-interface design enables both high-speed digital communication and analog-compatible fail-operational signaling in the A1338LLETR-P-T.
How is the zero-degree angle configured on the A1338LLETR-P-T?
The zero-degree angle (discontinuity point) on the A1338LLETR-P-T is programmable via EEPROM and physically controlled by the BIAS_1 pin. BIAS_1 is tied to GND or pulled up to 3.3 V to define magnetic polarity interpretation (CW/CCW), while EEPROM address 0x1C stores the calibrated 0° offset value. This two-layer configuration allows factory end-of-line adjustment and field recalibration without hardware changes - a core capability of the A1338LLETR-P-T's on-chip EEPROM with ECC.
What is the maximum rotational speed the A1338LLETR-P-T can accurately measure?
At full accuracy, the A1338LLETR-P-T measures up to 7600 rpm. Above this speed, angular latency increases linearly (e.g., 60 µs × rpm/16 × 6), causing measurable lag - for example, ~2.8° lag at 7600 rpm. The device continues operating up to 30,000 rpm but with reduced accuracy due to sampling limitations. This performance envelope is defined in the A1338LLETR-P-T's High RPM mode, where 25 µs refresh rate minimizes latency while maintaining 10-bit resolution.
Does the A1338LLETR-P-T include built-in diagnostics for functional safety compliance?
Yes, the A1338LLETR-P-T includes user-controlled Logic Built-In Self-Test (LBIST), full-signal-path diagnostics, 4-bit CRC on SPI messages, and programmable missing-magnet error flags - all supporting ASIL-B development. LBIST executes in 23 ms and covers >70% of logic in 10 ms. Diagnostics are initiated via SPI or PWM command sequences and report status through dedicated registers. These features are integral to the A1338LLETR-P-T's architecture and documented in its functional safety manual.
Can the A1338LLETR-P-T operate from a 12 V automotive battery without external regulation?
Yes, the A1338LLETR-P-T accepts 3.7 V to 16 V directly on VCC_1, enabling connection to an unregulated 12 V battery rail. Its absolute maximum VCC is 26.5 V, and reverse-battery protection limits current to –5 mA at –18 V. Undervoltage lockout activates between 2.9 V and 3.6 V, preventing erratic operation during cranking. This wide-input, ruggedized supply design is a key enabler for under-hood deployment in the A1338LLETR-P-T.
A1338LLETR-P-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Package/Case:
- 14-TSSOP (0.173", 4.40mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- -
- For Measuring:
- Angle
- Technology:
- Hall Effect
- Rotation Angle - Electrical, Mechanical:
- 0° ~ 360°, Continuous
- Linear Range:
- -
- Output:
- PWM, 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:
- 14-TSSOP
A1338LLETR-P-T FAQ
1.How can I place an order for A1338LLETR-P-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A1338LLETR-P-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-P-T reliable?
The price and inventory of A1338LLETR-P-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-P-T is usually 5 days.
3.What payment methods are accepted for A1338LLETR-P-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A1338LLETR-P-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A1338LLETR-P-T?
A1338LLETR-P-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A1338LLETR-P-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-P-T?
For technical support, including A1338LLETR-P-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A1338LLETR-P-T requirements.
6.How does Aetrix verify that A1338LLETR-P-T is sourced from the original manufacturer or authorized distributors?
All A1338LLETR-P-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-P-T meets industry standards.
7.What is the process for return or replacement of A1338LLETR-P-T?
All A1338LLETR-P-T units undergo pre-shipment inspection (PSI). If there is an issue with A1338LLETR-P-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-P-T part is unused and in its original packaging.
Return procedure for A1338LLETR-P-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A1338LLETR-P-T Tags
-
TLV493DA1B6HTSA2
Infineon Technologies
-
EVW-AE4001B14
Panasonic Electronic Components
-
3382G-1-103G
Bourns Inc.
-
TLE5501E0001XUMA1
Infineon Technologies
-
HAL830UT-A
TDK-Micronas GmbH
-
TLE5009E1000FUMA1
Infineon Technologies
-
TLE5501E0002XUMA1
Infineon Technologies
-
HAL3725DJ-A
TDK-Micronas GmbH
-
HAL3727DJ-A
TDK-Micronas GmbH
-
HMC1501-TR
Honeywell Aerospace
-
HMC1512-TR
Honeywell Aerospace
-
AAS33001LLEATR-5
Allegro MicroSystems
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
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.
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.
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…
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…
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…
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 …
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…
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…
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…
