SoC Linear Motion Encoder Offers High Resolution

The AS5305 magnetic linear motion encoder IC makes linear-position measurements by sliding a single- or double-track multi-pole magnetic strip over the IC. Using a cost-effective single-track magnetic strip, the device makes an incremental measurement with a resolution as low as 14 µm per position step. The device supports magnetic strips with pole-pair dimensions between 2.26 mm and 5.91 mm. An absolute linear displacement can be obtained by operating the AS5305 in conjunction with a double-track magnetic strip. The IC reads index information from the second magnetic strip, which represents a reference position within the mechanical displacement. The encoder can also be used as an off-axis device for rotational measurements, in conjunction with a multi-pole magnetic ring. When used with a 32-pole-pair magnetic ring, for example, the AS5305 can provide a resolution of 5120 positions per revolution. The device is a complete system-on-a-chip SoC), combining Hall elements and a signal processor. The AS5305 is available now in a lead-free TSSOP20 package. An automotive version, the AS5305A, will be fully qualified to AEC-Q100. It will be available in the first half of 2008. AUSTRIAMICROSYSTEMS USA INC., Raleigh, NC. (919) 676-5292.