Handling Power-Fail Interrupt (PFI) in HyperRAM Devices - KBA233428

[Chelladurai]

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Question: What should I do if power-fail interrupt (PFI) is detected in HyperRAM™ devices?

Answer: Power-fail interrupt (PFI) is detected in two cases:

Case 1:

Voltage in the V_CC pin drops below V_RST (0.7 V) level. In this case, the voltage in V_CC pin must be below V_RST level for a minimum time period of T_pd time. Normal power initialization can be performed when this timing is followed.

If the voltage in V_CC pin rises above V_RST (0.7 V) level before T_pd time, then perform hardware Reset for proper initialization of the chip.

Case 2:

Voltage in the V_CC pin drops below V_CC Min. (0.7 V) level but never drops below V_LKO level. In this case, the part will remain initialized and functions accurately when V_CC rises again above V_CC Min. For more details, refer the specific device datasheet (see Figure 1).

Figure 1. Power-Down or Voltage Drop