2.2.1 Requirements

Refer to figures “Recommended Power-up Sequence” and “Recommended Power-down Sequence” in the section “Power Considerations” of the SAMA5D2 data sheet for the applicable power supply sequencing.

The table “Power-up Timing Specification” establishes that:

• Power groups 1 and 2 can be established at the same time or Group 2 before Group 1,
• There should not be a delay of more than 1 ms between the establishment of any power supply from Group 1,
• There should be at least 1 ms delay between the VDDBU establishment and VDDFUSE turn-on
• NRST signal should be held low for at least 1 ms after the last established supply.

The table “Power-down Timing Specification” establishes that:

• NRST should be held low before or at the same time with the first supply turn-off,
• VDDFUSE should drop below 1V before or at the same time with the first supply turn-off.

All these power-up and power-down requirements are already implemented in the MCP16502/1 PMIC solutions.