Efficiency and combining of powerSoC

Dear All,

Can some please answer my questions below.

In the design I'm currently working on, we are going to use the Cyclone V GX.

I'm looking for a suitable power supply for this part a I found the powersoc website.

My system is battery powered (10Volt) and for that reason only a handfull of the powersoc's

can be used. The disadvantage of these situation is that the high VIN/VOUT voltage difference

leads to a lower converter efficiency.

It is clear to me that I need to stay within the 30mV accuracy for the FPGA core voltage, this can be

done with the EN2360QI. This part has a 2% accuracy an the ripple can be brougth down to about 7 mV (optimum)

But the efficiency is only 83% and dropping fast below 1,5A.

Is it possible to combine two DC-DC converters to get a better efficiency, so let's say we use the EN2340QI to

transform the 10V input down to 5V and then we use the EN6360 to transform the 5V input down to 1.1V.

The EN2340QI can achieve an efficiency of 93% and the EN63A0 an efficiency of 90%.

If you can afford the space, is this a possibility? Is the output ripple of the second converter still lower

than the 30mV than required?

Or do you have any other parts or recommendations to improve the efficiency? also with light load conditions?

With kind regards,

Andre Dekker