Obviously, for high-speed applications ... with and without a 1x amplifier This circuit demonstrates the power of a 1x amplifier. Both voltage dividers produce 2.5V with no load.

What we could perhaps all agree on, though, is that getting 300 volts out of a USB power supply ... the safest looking circuits we’ve seen in recent memory. Every high voltage part is hidden ...

they can be represented as part of small signal model as shown below Noise Analysis of Common Source Amplifier with resistive load: The small signal equivalent of above circuit including noise sources ...