Texas Instruments TPS54973EVM-017, User Manual, Page: 14 / 34

Modifications
1-6
connector terminals, while leaving J3 open. Headers J5 and J6 are provided
to select two, three, or four series diodes. Install a jumper across the header
to bypass the adjacent diode. Care must be taken to use the correct number
of diodes for the application. Under no circumstances can the output voltage
be allowed to precharge to a level higher than the preset output voltage. If this
condition occurs during startup, the TPS54973 device does not begin
switching. If a voltage transient on the precharge voltage source causes the
series diodes to conduct, current may be sunk through the low side FET in the
device, possibly damaging the device. The actual voltage drop across the
diodes during startup depends on the initial load condition of the circuit as well
as the ambient temperature.
1.3.5 Input Capacitor
An onboard electrolytic input capacitor may be added at C1.