AAS33051: Precision Angle Sensor IC with Incremental and Motor Commutation Outputs and On-Chip Linearization

The AAS33051 is a 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 to calculate the angular position information, and multiple output formats: serial protocol (SPI), pulse-width modulation (PWM), and either motor commutation (UVW) or encoder outputs (A, B, I). It also includes on-chip EEPROM technology, capable of supporting up to 100 read/write cycles, for flexible programming of calibration
parameters. The AAS33051 is ideal for automotive applications requiring 0° to 360° angle measurements, such as electronic power steering (EPS), electronic power braking (EPB or IDB),
transmission actuators, and BLDC pumps.

The AAS33051 includes on-chip 32 segment linearization. This can be used to calibrate out errors due to misalignment between the magnet and the sensor or imperfect magnetization of the target magnet (which can present itself as a misalignment of the magnet to the sensor).

The AAS33051 supports customer integration into safetycritical applications.

The AAS33051 is available in a dual-die 24-pin eTSSOP and a single-die 14-pin TSSOP package. The packages are lead (Pb) free with 100% matte-tin leadframe plating. The 1 mm thin package reduces the minimum air gap between the CVH transducer and the target magnet. The AAS33051 device is pin-compatible with the A1339 to enable easy migration.

AAS33051 was developed in accordance with ISO 26262:2011 as a hardware safety element out of context. The single die version was designed to meet ASIL B capability (pending assessment), and the dual die version designed to meet ASIL Dcapability (pending assessment), for use in automotive safety-related systems when integrated and used in the manner prescribed in the applicable safety manual and datasheet.

• Contactless 0° to 360° angle sensor IC, for angular position, rotational speed, and direction measurement
  • Capable of sensing magnet rotational speeds targeting 12.5-bit effective resolution with 300 G field; higher effective resolution possible at higher field strengths
  • Circular Vertical Hall (CVH) technology provides a single channel sensor system, with air gap independence
• On-chip 32 segment linearization to improve angle accuracy
  • Reduces impact of magnet to sensor misalignment
  • Reduces impact of imperfect magnetization of target magnet
• Developed as a Safety Element out of Context (SEooC) in accordance with ISO 26262:2011 requirements for hardware product development for use in safety-critical applications (pending assessment)
• High diagnostic coverage
  • On-chip diagnostics include logic built-in self-test (LBIST), signal path diagnostics, and watchdogs to support safety critical applications
  • 4-bit CRC on SPI
• On-chip EEPROM for storing factory and customer calibration parameters
  • Single-bit error correction; dual-bit error detection, error correction control (ECC)
• Supports operating in harsh conditions required for automotive and industrial applications, including direct connection to 12 V battery
  • Operating temperature range from –40°C to 150°C
  • Operating supply voltage range from 3.7 to 18 V, absolute maximum of 28 V continuous
    ♦Can support ISO 7637-2 Pulse 5b up to 39 V
• Low power mode and turns counter feature to keep track of motor position in automotive applications when the vehicle is turned off
  • Loss of power is indicated by reset flag
  • Externally stored positions can be written back to the turns counter
  • Multiple output formats supported for ease of system integration
  • ABI and UVW interfaces provide high resolution and lowest latency angle information
  • PWM interface provides initial position for ABI/UVW interfaces
  • 10 MHz SPI for low latency angle and diagnostic information; enables multiple independent ICs to be connected to same bus
    ♦5 V SPI can be supported
  • Output resolution on ABI and UVW are selectable
• Multiple programming / configuration formats supported
  • The system can be completely controlled and programmed over SPI, including EEPROM writes
  • For system with limited pins available, writing and reading can be performed over VCC and PWM pins. This allows configuring the EEPROM in production line for a device with only ABI/UVW and PWM pins connected.
• 1 mm thin surface-mount TSSOP packages for both single and dual die versions to minimize air gap from target magnet to CVH transducer for improved field strength
  • Pin-compatible to single and dual die A1339 devices
  • Stacked dual die construction to improve channel-to-channel matching for systems that require redundant sensors