DA9053: the LDO4 output not active

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jeremye
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DA9053: the LDO4 output not active

We’ve just received the first versions of our new board which contains the DA9053 which we are using with NXP’s iMX6 processor.
I’ve based the design on Dialog’s application note AN-PM-31, which explains how to use the DA9053 with the iMX6DualLite.
The problem I’ve found is that one of the DA9053 supplies: the LDO4 is not coming on at power up (or at all). This is true for two out of two boards. All of the other supplies are starting normally. I’ve checked that there is no abnormally low resistance load or short on the LDO4 output. It is only connected to the CPU and two pull-down resistors (total 5k) and the absolute maximum possible load on it is 126mA.
According to schematic and layout the input power for LDO4 is connected (VDD_LDO3_4).

Would it be possible to check whether the LDO4 is supposed to turn on at power up?
Are there other possible reasons for LDO4 not working?
The version of the DA9053 we’re using is the: DA9053-60HA2 and it is using the standard factory programming. I believe that this is the DA9053-60_iMX6DL_1R2_1D46.ini

Device: 
ED_Dialog
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Hello Jeremye,

Hello Jeremye,

Let me look into that for you.

Kind regards,

Elliott Dexter

ED_Dialog
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Hi Jeremye,

Hi Jeremye,

 

LDO4 has not been configured to turn on automatically; this is highlighted in Figure 4 and Table 2 of AN-PM-31. You can turn on the LDO via an I2C write.

Kind regards,

Elliott Dexter 

jeremye
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Thanks Elliott,

Thanks Elliott,
That certainly explains the finding and points me to a solution.
If I load that .ini into the power commander software does it show me that LDO4 is disabled, do you know?

ED_Dialog
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Hello Jeremye,

Hello Jeremye,

 

It should show that LDO4, start-up slot is in postion 0 (not in the seq). This shows that it will not turn on at start-up.

 

Kind regards,
Elliott Dexter