Hi,
We have just brought up our first revision/proto board using this evaluation circuit for our PoE PD. We have been doing some measurements on efficiency and the results correlate pretty well with the measurements you have done on TPS23730EVM-093 (Figure 6-13). Main difference is that we see a bit worse efficiency at light loads, but at high loads we are pretty much on par which is very good. However since our product will operate at light loads (around 200-250mA @ 12V output) maybe 95% of the time, we were wondering if you had any suggestions on how to improve light load efficiency? Even if it would compromise higher load efficiency.
From our initial investigation it looks like the main losses are in the transformer and secondary side inductor as they heat up quite a bit over time - but can't really understand why as they should be far from reaching saturation at such light loads. All switching transistors are pretty much at room temperature.
