Hi need assistant selecting a DC to DC converter based on "load transient response".
The selected Dc-DC will see transients from 0 to 4 amps. (rise and fall time ~20us @ 18vs).
Duly cycle ~100hz, Noise p-p of 30mv
The TPS540/ LM2678 were evaluated on the bemch, the results were similar to:
The Conclusion was:
A fast transient response from a full load to no load can present some large overshoots for non synchronous designs. The main reason is when the load is removed, the low-side switch cannot sink current to help return the output to regulation after the overshoot. Instead the device stops switching and the output voltage must decay through any parasitic load. The device will only start switching once the output voltage has began to drop below the target value and the voltage may drop too far before the loop can respond.
thanks
The Input is 24v,
.
