About LDO3 Current of PCA9540AA

[mark_kim]

Dear

Considering the maximum supply current condition of the I.MX8 Mini, could you please let me know if I can use PCA9540AA?

when see the reference circuit,  LDO3 of PCA9540AA is used to supply current to VDD_24M_XTAL_1P8,  VDD_ANA0_1P8 ,  VDD_ARM_PLL_1P8 and other power pins.

From the datasheet of I.MX8 Mini, We can see maxmum supply currents on table 12.

when I sum the max current related to the above power pins, it is 350mA. 

 and The figure is above the 300mA current available at pca9450aa.

So I wanna take your tips on how PCA9540AA can operate well at maxim supply current condition descripted on table 12 ( I.MX8 Mini datasheet)

thank you

Best Regards

Mark Kim

[mark_kim]

Dear Rita Wang

Could let me have your tips for this ticket?

thank you

Best Regards

Mark Kim

[Rita_Wang]

You are welcome~~

[florian_arndt]

Hi @mark_kim,

as Rita already said: Don't worry about these values.

The PCA9450AA is the right PMIC from NXP built specifically for i.MX 8M Mini. In my company we also use it for i.MX 8M Nano designs although in this case PCA9450B is proposed from NXP...

Both systems run without problems for some years now and we didn't have any problems with it as of today. Even in higher quantities.

Best regards,
Florian

[Rita_Wang]

You can see that overdrive mode and normal mode have different voltage supply, you can see in the section:3.1.3 Operating ranges

[mark_kim]

Hi Rita Wang

Maybe, My question seemed not to be clear to you.

I just want to know How PCA9540AA and I.MX8M mini can operate together even though available current by PCA9450AA is less than max current described on table 13 below.

Please see table 13 on the datasheet of I.MX8M mini.

The above total current is over current supplied from PCA9450AA, 300mA.

thank you

Best regards

Mark Kim

[Rita_Wang · Accepted solution]

Dear @mark_kim ,

Do not worry about it, no problem.

Because VDD_ANA0/1_1P8 and VDD_ARM.PLL_1P8/VDD_24MnXTAL_1P8 will not reach their maximum current simultaneously.
Table: 13 currents can not be reached in real applications.

Hope this can do help for you

I also email to you for it.

Wish you have a nice day

Best Regards

Rita