Can the power supply ramp up faster than the values specified in the F-RAM datasheet?
The tVR and tVF parameters given in F-RAM datasheets specify the power up and power down ramp rates required for Cypress FRAM devices. Note that the unit of the time is specified as µs/V and is a minimum specification. This is the minimum time required for a 1-V change in supply voltage.
Example: For the part FM24CL16B, tVR = 30 µs/V
This part will work properly if the power up ramp rate is more than 30 µs/V, meaning that the power supply should ramp up slowly for proper operation. However, if the power supply ramps up quicker than 30 µs/V, it will cause undesired behavior in the F-RAM.
Cypress does not guarantee the proper operation of F-RAMs if the power up/down ramp rate exceeds the datasheet limits.
Please refer below diagram for more details.