1. Are there no problems if two kinds of powers are turned on/off simultaneously?
2. What problem occur when the order of powering on/off is not followed?
If two kinds of power supply voltage satisfy the following formula, there is no problem.
Voltage of 1.5V/1.7V/1.8V/1.9V/2.0V power ≤ Voltage of 3.3V power
Power ON interval of 3.3V power and 1.5V/1.7V/1.8V/1.9V/2.0V power is recommended to be within 1ms but please note that this is reference value. The pin states remain undefined untill all power is supplied and a high level is input at the CA pin and a low level at the /RESETpin.The system design must ensure that these undefined states do not cause erroneous system operation.