An optical sensor SoC from Avago Technologies features a small pin-count for mice, trackballs and other human interface devices. The compact, integrated ADNS-2700 LED-based sensor eliminates the need for an external microcontroller and requires few passive components, delivering ease-of-design and low system costs.
The sensor contains an image acquisition system, a digital signal processor and a USB stream output in a small-footprint eight-pin dual in-line package. With an integrated oscillator and pull-up resistor, the device also reduces external component count and does not need precision optical alignment, facilitating high-volume assembly. On-chip one-time-programming memory enables designers to program their own product and vendor identification information. It helps designers select the resolution setting and sensor orientation without a software driver, providing streamlined customisation. The sensor provides precise, high-speed tracking for mice with motion detection of up to 30 in/s and 8g acceleration detection. The programmable resolution ranges from 250 up to 1250 counts per inch for accurate, sensitive navigation.
The sensor measures changes in position by optically acquiring sequential surface images and mathematically determining the direction and magnitude of movement from the changes in the image. The DSP automatically processes images from the IAS to determine the direction and distance of motion. It then generates the relative displacement values and converts this to USB motion data.
