Electronics Weekly Electronics Design & Components Tech News
“Developers have the choice between two sensor models – HAL 3020 and HAL 3021 – for fast angle determination, with which they can meet the need for robust motor position detection and ISO 26262-compliant development. The components have differential or single-ended sine and cosine analog outputs with integrated open-circuit detection,” according to component distributor Rutronik, which is stocking the parts.”
HAL 3021 is optimised for best performance including: robustness against static and dynamic mechanical tolerances, signal-to-noise ratio and angular error drift, and it supports closer air gaps and smaller target magnets. HAL 3020 trades some performance for lower power consumption.
“This product is defined as SEooC (safety element out-of-context) ASIL C ready according to ISO 26262:2018 – the device can be integrated in automotive safety-related systems up to ASIL D,” said manufacturer Micronas. “HAL 302x contains on-board diagnostic features, such as over-voltage and under-voltage detection as well as wire-break monitoring during normal operation.”
The devices are intended to work on the rotational axis with their tops perpendicular to that axis (see diagram). A two pole magnet on the rotating shaft provides the measurement target. Six internal Hall bridges and associated processing extract the wanted signal while rejecting stray fields – constant and changing – according to ISO 11452-8:2015.
“The magnet can be positioned above or below the sensor,” said Rutronik. “Errors due to supply voltage and temperature fluctuations can be minimised by the measuring principle of the Hall plate array.”
According to the data brief, the four analogue outputs can be ratiometric with the supply rail, or non-ratiometric.
Non-volatile eeprom memory on the IC can be programmed (using the output pin) to individually adjust sine and cosine signal amplification, offset, absolute 0° position, orthogonality and bandwidth.
Operation is from 3.0 to 5.5V, in ambients up to 160°C (abs max) with the junction over -40 to +170°C. Packaging is 8pin SOIC8.
Over-voltage and reverse-voltage protection are included. Qualification is to AEC-Q100.
Rutronik sees them being used for commutating brushless dc motors, for starter-generators, in electronic valves and in electronic pumps.
