I built a step down switching regulator based on a Diodes AP5100 using the datasheet example circuit with this layout. The voltage is being stepped down from 15V to 12V and the AP5100 is heating up to 60°C+ under light or no load at all(0-40ma). At about 80ma load the temperature is more reasonable at about 40°C and runs relatively cool(low 30s) above 150ma. The circuit that is being powered by this operates at low current(<20ma) 85% of the time and the other 15% at about 250-500ma, so it would be nice to have it run cooler under the light load. Should I try increasing the inductor size to improve the light load efficiency?
The circuit that I am using is shown above and it's for 3.3v. The only change that I have made is to use 3.6k with 49.9k to get 12V. And also, I have substituted the B230A with a STPS2L60A. The caps are all ceramics at the proper voltages including the 10uF(35V) and 22uF(25V). The inductor is 3.3uH with these specs.