The Canon IXUS 170 has a CCD sensor type which is better than the MOS sensor type found on most Compact camera digital cameras that are a similar age to it. CCD sensors produce high quality, low-noise images but consume a lot more power than CMOS sensors. CCD is the most common image sensor type used in digital cameras.
This digital camera's sensor type (CCD) is in fact the best sensor type amongst all Compact camera digital cameras that are a similar age to the IXUS 170.
Amongst similar types of digital camera the worst sensor type is MOS.