ams has introduced the AS5147P, an ultra high-speed magnetic rotary position sensor which offers reliable performance in automotive applications, compatible with the requirements of the ISO 26262 functional safety standard.
Providing accurate absolute and 12-bit incremental measurement outputs at speeds up to 28,000 revolutions per minute (rpm), the AS5147P is ideal for safety-critical automotive applications.
Its appeal to automotive system designers rests on a combination of high measurement accuracy at high rotation speeds, high reliability, low system cost and support for standards compliance.
The AS5147P draws on patented Dynamic Angle Error Correction (DAECTM) technology to deliver accurate position measurements even at extremely high rotation speeds. The DAEC compensation scheme reduces the propagation delay inherent in the sensor’s signal chain to almost zero. As a result, the AS5147P’s angle error is a negligible 0.02° at 1.7krpm, 0.17° at 14.5krpm and 0.34° at 28krpm. The DAEC function enables the device to refresh its measurement output every 1.9μs.
High reliability and low system cost in automotive applications are assured by the AS5147P’s intrinsic immunity to stray magnetic fields. Strong stray magnetic fields are present in vehicles, particularly those with a partially or wholly electric drivetrain. These stray magnetic fields are much stronger than that of the small target magnet with which a magnetic position sensor is paired.
The unique differential sensing principle of the magnetic position sensors from ams makes them immune by design to stray magnetism. This means that automotive system designers can avoid the need to incorporate bulky and expensive magnetic shielding into their products, reducing their size, weight and cost when compared to designs based on competing magnetic position sensor ICs. The high sensitivity of the AS5147P also enables the use of a small, 6mm diameter, low-cost target magnet.
- 14-bit core resolution
- Takes both absolute and incremental (ABI) angle measurements
- Standard UVW commutation interface for brushless DC motors
- Detection of magnetic field-strength threshold
- Integral detection of loss of magnet
- Serial peripheral interface to host microcontroller
- Developed in accordance with ISO 26262 Safety Element out of Context
- Electric power steering
- Brake and accelerator pedals
- Double-clutch transmissions
- Starter motors
- Windscreen-wiper motors