8.3 Power-down Considerations

The figure below shows the power-down sequence that starts by asserting the NRST line to 0. Once NRST is asserted, the supply inputs can be immediately shut down without any specific timing or order. VDDBU may not be shut down if the application uses a backup battery on this supply input. In applications where VDDFUSE is powered, it is mandatory to shut down VDDFUSE prior to removing any other supply. VDDFUSE can be removed before or after asserting the NRST signal.

Figure 8-2. Recommended Power-down Sequence

Table 8-3. Power-down Timing Specification
Symbol	Parameter	Conditions	Min	Max	Unit
t_RSTPD	Reset delay at power-down	From NRST low to the first supply turn-off	0	–	ms
t₁	VDDFUSE delay at shut-down	From VDDFUSE < 1V to the first supply turn-off	0	–	ms