Rotary Encoder Also Detects Magnetic Tilt, Vertical Distance

A magnetic rotary encoder with 12-bit resolution, the AS5046 from austriamicrosystems, offers tilt and vertical distance detection of a magnet placed above it in addition to traditional rotary detection. The ability to detect magnet tilt lets designers use the encoder in very small-form-factor joysticks. Users only have to replace the diametrically polarized magnet with an axially polarized one, according to the company. Also, the ability to detect vertical distances over several millimeters suits the AS5046 for contact-less, multi-axis human interface devices, such as navigational knobs. The device is a complete system-on-a-chip, combining the Hall-effect elements with a signal processor.

The encoder communicates with an external microcontroller over a two-wire serial interface. For standalone operation, the AS5046 provides a programmable ratiometric analog output. The device comes in a lead-free SSOP16 package. It can run off of a 3.3- or a 5-V supply and is specified for a –40°C to 125°C ambient temperature. Detailed application notes are available, along with demo boards and free software tools, to facilitate customer designs based on the AS5046.