Why AN4509 measured the power consumption with VDDHIGH_IN = 2.78V?

[satoshishimoda]

Hi community,

Our partner have a question about i.MX6DQ VDDHIHG_IN.

Please see AN4509, the power consumption data was measured with VDDHIH_IN = 2.78V.

However, 2.78V is lower than operating range in Table 6 of IMX6DQCEC Rev.3.

Why AN4509 measured the power consumption with VDDHIGH_IN = 2.78V?

Is this no problem?

Best Regards,

Satoshi Shimoda

[igorpadykov · Accepted solution]

Hi Satoshi

you are right, this is no problem, because

VDDHIHG_IN supplies only LDOs, according to

IMX6DQRM Figure 50-1. Power system overview.

Typical 125 mV difference between LDO In and Output is

sufficient for LDO operation, as suggests Footnote 4

Table 6 IMX6DQCEC

Best regards

igor

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[satoshishimoda]

Hi Igor,

Would you let me know the reason why AN4509 measured the power consumption with VDDHIGH_IN = 2.78V also?

For lower power consumption?

Best Regards,

Satoshi Shimoda

[igorpadykov]

Satoshi

I think measurements were carried out on early development,

when datasheet data were not fully characterized.

However difference between 2.78V and 2.8V is so small,

that seems no significant difference in power consumption one

can expect with 2.8V compared with 2.78V.

Best regards

igor

[satoshishimoda]

Hi Igor,

Thank you for your reply.

OK, I understood it is no problem.

But I think the datasheet should be modified if 2.78V is acceptable.

Also, VDD_SNVS_IN (min) should be modified if VDDHIGH_IN(min) will be modified since "VDD_SNVS_IN should be supplied from the same supply as VDD_HIGH_IN".

Best Regards,

Satoshi Shimoda