Does the LT8650S require an external boost capacitor? The datasheet pin description says:
"BST1 (Pin 24): This pin is used to provide a drive voltage, higher than the input voltage, to the top side power switch of channel 1. Place a 0.1μF boost capacitor as close as possible to the IC."
But the evaluation board and application examples do not have BST capacitor, as they are integrated inside the device itself.
Please could you let me know if I need an external BST capacitor.
You are correct. The next datasheet change will remove "Place a 0.1μF boost capacitor as close as possible to the IC."
So, the two BST capacitors are not required any more - but is it recommended to not foresee them at all? I.e. will it improve radiated noise if I remove them and keep the SW nodes smaller? Or are there side effects that make it worse?
Making switch node smaller and therefore inductor much closer to SW pin will definitely shorten hot loop and therefore expected lower radiated noise. This is recommended.