A1337: Precision, Hall-Effect Angle Sensor IC with SPI, and SENT or PWM Outputs


The A1337 is a 0° to 360° angle sensor IC that provides contactless high-resolution angular position information based on magnetic circular vertical Hall (CVH) technology. It has a system-on-chip (SoC) architecture that includes: a CVH front end, digital signal processing, digital SPI, and SENT or PWM outputs. It also includes on-chip EEPROM technology, capable of supporting up to 100 read/write cycles, for flexible end-of-line programming of calibration and configuration parameters. The A1337 is ideal for automotive applications requiring 0° to 360° angle measurements, such as electronic power steering (EPS), seatbelt motor position systems, rotary PRNDLs, and throttle systems.

The A1337 was designed with safety-critical application requirements in mind. It includes user-controlled, on-chip logic built-in self-test (LBIST) and full signal path diagnostics to enable customers to determine if the IC is operating in a proper manner.

The A1337 includes integrated Turns Counter and Low-Power Mode functions. The Low-Power Mode enables the device to be connected directly to the vehicle battery and minimizes power consumption when the vehicle is in the key-off state. The Turns Counter function allows the device to keep track of either 45° or 180° turns of the motor when the part is in Low-Power Mode, monitoring the motor position even when the vehicle is in the key-off state.

The A1337 supports a Low RPM mode for slower rate applications and a High RPM mode for high-speed applications. High RPM mode is for applications that require higher refresh rates to minimize error due to latency. Low RPM mode is for applications that require higher resolution operating at lower angular velocities.

The A1337 is available in a single-die 14-pin TSSOP and a dual-die 24-pin TSSOP. Both packages are lead (Pb) free with 100% mattetin leadframe plating.

Top Features

  • Contactless 0° to 360° angle sensor IC, for angular position and rotation direction measurement
    • Circular Vertical Hall (CVH) technology provides a single-channel sensor system, with air gap independence
  • 12-bit resolution possible in Low RPM mode, 10-bit resolution in High RPM mode
  • Angle Refresh Rate (output rate) configurable between 25 and 3200 μs through EEPROM programming
    • Capable of sensing magnetic rotational speeds up to 7600 rpm, and up to 30,000 rpm with reduced accuracy
  • SPI, and SENT (Single Edge Nibble Transmission) or PWM (Pulse-Width Modulation)*
  • SPI interface provides a robust communication protocol for fast angle readings*
    • SENT output supports four modes: SAEJ2716 (JAN2010) and Allegro proprietary options of Triggered SENT (TSENT), Sequential SENT (SSENT), and Addressable SENT (ASENT)*
    • Programmable via Manchester Encoding on the VCC line, reducing external wiring*
    • SPI and SENT interfaces allows use of multiple independent sensors for applications requiring redundancy*
  • Advanced diagnostics to support safety-critical applications, including:
    • On-chip, user-controlled logic built-in self-test (LBIST) and signal path diagnostics
    • 4-bit CRC on SPI messages
    • User-Programmable Missing Magnet Error flag for notifying controller of low magnetic field level
  • Diagnostics are initiated over the SPI or SENT interface and can directly test proper operation of the IC in safety-critical applications
  • Integrated Turns Counter tracks magnet rotation in CW/CCW direction from –1280 to +1280 counts, even when vehicle is in key-off state
    • Count updates are user-selectable to be every 180° or every 45° degree of magnet rotation
    • WAKE pin for external wake-up trigger can be used to automatically detect motion > 100 rpm
  • Low-Power Mode enables direct connection to vehicle battery
    • User-programmable duty cycle optimizes low-power mode current consumption (typically 85 μA per die)
    • Ultralow-power Transport mode
  • EEPROM with Error Correction Control (ECC) configuration, sensor calibration including end-of line adjustments like programmable angle reference (0°) position and rotation direction (CW or CCW)
  • Available in both single-die and dual-die configurations
    • Dual-die devices contain two independent die housed within a single package
  • Absolute maximum VCC of 26.5 V for increased robustness and direct connection to automotive vehicle battery

    * See Selection Guide for more details.

Part Number Specifications and Availability

Part Number Package Type Temperature RoHS
Part Composition /
RoHS Data
Comments Samples Check Stock
A1337LLETR-P-DD-T n/a -20°C to 85°C Yes View Data Contact your
local sales rep
Distributor Stock
A1337LLETR-P-T n/a -20°C to 85°C Yes View Data Contact your
local sales rep
Distributor Stock
A1337LLETR-DD-T 24-lead TSSOP -40°C to 150°C Yes View Data Contact your
local sales rep
Distributor Stock
A1337LLETR-T 14-lead TSSOP -40°C to 150°C Yes View Data Contact your
local sales rep
Distributor Stock
ASEK1337-8-SUBKIT-T DEMO BOARD -40°C to 150°C No -- Contact your
local sales rep
Distributor Stock
ASEK1337-8-T-KIT DEMO BOARD -40°C to 150°C No -- Contact your
local sales rep
Distributor Stock

Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.


A1337 Packages

Design Support Tools

A1337 Software

A1337 Hardware (User Guide)

ASEK-20 Sensor Evaluation Kit

A1337 Programming Board Schematics 

NOTE: When ordering an ASEK kit for the A1337 please order ASEK1337-8-T-KIT.