At Electronica 2024, TDK unveiled the IAM-20685HP and IAM-20689 six-axis MEMS inertial measurement units (IMUs), enhancing its InvenSense SmartAutomotive portfolio. The two new MEMS devices provide more capable options over prior IMU offerings.
Specialized for Safety-Critical ADAS Systems
The IAM-20685HP is designed for non-critical ADAS applications like positioning and vision systems. It achieves ASIL B compliance across all technical safety requirements, balancing performance and cost-effectiveness. IAM-20689 with enhanced embedded diagnostics and safety mechanisms, it is suitable for safety-critical applications such as drive-by-wire systems, stability control, and rollover detection.
Both IMUs are developed as Safety Element Out of Context (SEooC) components, allowing flexibility for integration into a range of ADAS and safety systems.
Block diagram of the IAM-20685HP.
Key Features and Specifications
The IAM-20685HP and IAM-20689 share a range of advanced features:
- 16-bit ADCs for precise measurement.
- Programmable digital filters for tailored signal processing.
- Internal self-tests to ensure operational integrity.
- Power supply: Operates between 3.0 V and 5.5 V with digital I/O in the same range.
- Low power consumption: Current draw below 10 mA.
- Communication: Supports a 10-MHz SPI bus with CRC for robust data transmission.
The IAM-20685HP incorporates 20 internal safety mechanisms, providing lifetime fault detection with real-time monitoring capabilities. Its design focuses on economical implementation for systems where ASIL B suffices, such as vision stabilization and non-critical navigation.
The IAM-20689, in addition to the core features, includes 10 additional safety mechanisms and heightened design and manufacturing controls to meet stringent ASIL D requirements. It is ideal for applications demanding higher safety assurance.
Six-Axis Integration: A Game-Changer
TDK’s new IMUs integrate a three-axis accelerometer and a three-axis gyroscope into a single package, ensuring safety. Most competitive solutions require two separate components for full six-axis functionality. By consolidating into a compact 4.5 mm x 4.5 mm x 1.1 mm QFN package, TDK reduces the parts count and device size, offering greater design flexibility for automotive engineers.
“As of yesterday, stability control and the rollover detection required two different components,” said Alberto Marinoni, TDK Invensense's senior director of automotive product marketing. “Having only three or five axes did not allow tier-one to measure all the dynamics of the vehicle in a single component. By having a single six axis in one central unit, you can combine stability control and rollover detection in the same central unit.”
Conclusion
The introduction of the IAM-20685HP and IAM-20689 IMUs represents a significant leap forward in ADAS and automotive safety technology. By combining six-axis functionality, high safety certifications, and compact design, TDK continues to innovate in the MEMS sensor space, addressing the growing demands of next-generation autonomous and semi-autonomous vehicles.
