Nikon P300 has a 12.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor and features Expeed C2 processor. On the other hand, Sony W690 has a 16.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized CCD sensor and features BIONZ processor.
Below you can see the P300 and W690 sensor size comparison.
Nikon P300 and Sony W690 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Nikon P300 has 32% larger pixel area compared to Sony W690, it has potential to collect more light on pixel level hence have less noise in low light / High ISO images.