When powering up a C6454 device, suppose the power sequencing looks like this:
- 3.3V comes up first
- 1.25V comes up next
- 1.8V comes up last
However, the 1.25V rail rises from 0 – 800mV in about 100us, drops to 400mv as the power device starts up, then rises back up steadily to 1.25V after 2-3ms. The 1.8V rail does something similar as well although with not quite the same dip.
Can the DSP handle this irregular power sequence? The power device in use is the TPS54373.