I am looking for a synchronous buck converter with high efficiency.
In the past the customer I used the TPS54061 but the current output is too low for my new application. The 0.5A version of the part (TPS4060) is not synchronous so the efficiency is not as good.
I'm now looking at the LM46000 but for some reason the 2A version (LM46002) seems to be more efficient so I would rather use that even though the current specs don’t demand it. Is there any specific reason that the efficiency of the LM46002 is higher than the LM46000? Here are more details of my system:
Freq: 50Khz-400Khz
Input: 40VDC
Input Max: 60VDC
Output: 3.2V
Current during peak: ~275mA.
Current in normal operation: 50mA-100mA.
The part will spend 99% of its life doing 3.2V and ~100mA on 40VDC input. This is where the design should be optimized around. It's ok if the efficiency drops for the 1% of the time when the draw is closer to 300mA but it's necessary for the design to be able to supply that.
Unfortunately the efficiency curves in the datasheet don’t cover this use case so I’m not sure if the LM46002 is actually more efficient than the LM46000 for this specific case. Is the LM46002 the best bet or is there something else I should look at here?
