The start-up voltage waveform of the TPS54350EVM−235 is shown in Figure 2-12. The waveform shows the nominal 12-V input voltage in Ch. 1, the 3.3-V output ramping up in Ch. 2, and the PWRGD signal in Ch. 3. Note that the PWRGD signal is pulled up externally to 3.3 V.

Figure 2-12 Powering Up

The corresponding power-down waveform is shown in Figure 2-13. The channel assignments are the same as in the power-up waveform in Figure 2-12.

Figure 2-13 Powering Down