Texas Instruments TPS543620, User Manual

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3.9 Start-up and Shutdown with VIN
Figure 3-30 and Figure 3-31 show the start-up and shutdown waveforms for U2 with VIN. In Figure 3-30 , the VIN
voltage ramps up and output voltage ramps up after the input and EN pin voltages reach their respective UVLO
threshold. In
Figure 3-31 , the VIN voltage ramps down and the TPS543620 shuts down when the input or EN
pin voltage reach their respective UVLO threshold. The rate at which VIN ramps down changes as soon as the
TPS543620 is disabled because it is no longer loading the input supply.
Time (400 µs/div)
VOUT (500 mV/div)
VIN (10 V/div)
EN (2 V/div)
PGOOD (5 V/div)
Figure 3-30. U2 Start-up with VIN – 0.3-Ω Load
Time (1 ms/div)
VOUT (500 mV/div)
VIN (10 V/div)
EN (2 V/div)
PGOOD (5 V/div)
Figure 3-31. U2 Shutdown with VIN – 0.3-Ω Load
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SLVUBQ1A – AUGUST 2020 – REVISED MAY 2021
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TPS543620 SWIFT™ Step-Down Converter Evaluation Module User's Guide 21
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