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Current limit function of LDO_1P1

Question asked by Takayuki Ishii on May 20, 2018
Latest reply on May 22, 2018 by Takayuki Ishii

Hello community,


About VDDHIGH_IN voltage of SABRE_SD i.MX6Q board,

It will dropped while wake from deep sleep mode.



It seems that in-rush current to charge a bulk capacitor of NVCC_PLL_OUT.

So enabled current limit of LDO_1P1 by setting PMU_REG_1P1[ENABLE_ILIMIT] bit,

it seems that in-rush current is limited and voltage drop down has been resolved.


But lamp up of NVCC_PLL_OUT is slower than disable of current limit.


Is it OK to use a current limit function while wake up from deep sleep mode?


[Test environment]

Board : SABRE-SD i.MX6Q

OS : Linux BSP 4.9.11_1.0.0


Probe point : 

 ch1 : sh17 (VDDHIGH_IN)

 ch2 : sh17 (VDDHIGH_IN)

 ch3 : SW1_1 (CPUPWRON)

 ch4 : R208 (NVCC_PLL_OUT)


Deep Sleep Mode : 

 Use a configuration of 5.2 Deep Sleep Mode (LPM6) in AN4509.


Best regards,