Texas Instruments TPS54380EVM-001, User Manual

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Powering Up and Down
2-11 Test Setup and Results
Figure 2–12. Powering Down With Tracking
VO I/O 500 mV/div
Time Scale 1 ms/div
VO CORE
500 mV/div
The TPS54380EVM–001 EVM provides the ability to change the slew rate of
output voltage of core regulator by using jumper JP2 (see schematic in
Figure 4–1). If jumper JP2 is set so that R8 is connected in parallel to R7,
ratiometric power sequencing is implemented. For ratiometric sequencing the
following condition needs to be met:
if R6 = 10 k
Ω
then R8 II R7 = (R7
×
0.891)/(V
I/O
– 0.891).
In this case the I/O and core voltages reach their nominal values at the same
time. The waveforms for ratiometric powering up and down are shown in
Figure 2–13 and Figure 2–14.