We are designing a PCB with IMX6UL (MCIMX6G2CVM05AA) and PF3001. The design uses a standard single cell Lithium Ion battery(Nominal:3.7V) as its power source.Hence we have not used the VPWR LDO in our design(grounded VPWR pin)
We are using LDO3 for 2.8V and LDO4 for 1.8V supplies, for the peripherals on-board. According to the PF3001 datasheet,the maximum input voltage specified for VLDO34IN is 3.6V, when VPWR LDO is not used.
Please find the snapshot image below for reference.
We have provided SW2 regulator output(3.3V) for VLDO34IN input,to meet the input range specification.
Can you please clarify the below doubts.
Q1: According to the default power ON sequence of PF3001, SW2 and LDO4 starts at the same time.
Is there an issue on power ON sequence/timing ,when we provide SW2 regulator output to VLDO34IN.
Q2: Is that acceptable to power VLDO34IN with voltages higher than 3.6V(maximum of 4.3V), when VPWR LDO is not used.
Can you please explain what restricts the input voltage for LDO34IN,when VPWR is used or not.
Your help is highly appreciated.