LM5069: Un Regulated power as input?

Conroy

Unregulated as in a Buss Converter? Keep in mind that a voltage transient on the input will supply current through the FET per: I = Cdv/dt so surge currents will be seen by the current sense resistor and you will need to account for that for CL purposes.

In normal operation, all Vin transients will pass through the fully enhanced FET to the output. If you can control the transient level and duration, you can clamp the transient by using a Gate to Ground zener. The clamped voltage will be ~ Vzener - Vth of the FET. However, the FET is then operating in fully linear region and Pdiss will be very high. Hence the need to know exactly the voltage and time duration so you don't exceed the energy rating (SOA) of the FET. i.e. be very careful doing this and with set standards for transients that you can design to. If you don't care about keeping Vout at a sustained point, then the OVLO can be used to shut down the FET and restart once Vin comes back into normal operation range.

Brian