About max supply current in i.MX6Q (Continue).

[keitanagashima]

Dear All,

Hello. I have questions about max supply current in i.MX6Q.

And, my question is series of below community.

About max supply current in i.MX6Q.

[From community's answer]

>Table 8 does not describe transients currents, that is very short in time.

>All spikes/ripples are averaged and included in that figure.

>Table specifies average current for normal conditions

[Q1]

See attached file.

Where does max value of "Table 8. Maximum Supply Currents" show in attached case?

(We think that it is blue line.)

[Q2]

How many is the MAX value of DC Current which excluded Transient Current?

[Q3]

>All spikes/ripples are averaged and included in that figure.

How did freescale calculate the Table 8's max value?

How did you average spike/ripples and include Table 8?

Best Regards,

Keita

[igorpadykov · Accepted solution]

Hi Keita

1. from attached picture it is not possible to say max. current,

    for that, current value should be averaged:

Mean of a function - Wikipedia, the free encyclopedia

this can be done using RC circuit or millivoltmeter

(it has internal averaging circuit)

2.  Spikes or "Transient Current" as you call it, are included

in average current value, this value is given in datasheet

Table  Maximum Supply Currents

3.

>How did freescale calculate the Table 8's max value?

It was not calculated using formula, processor run special code

"Power Virus" and measurements were carried out using procedure

described in sect.2.7 Measuring Points on the Freescale SABRE SD Board

Application Note AN4509 (Rev. 0, 10/2012) "i.MX 6Dual/6Quad Power Consumption

Measurement"

http://www.freescale.com/files/32bit/doc/app_note/AN4509.pdf

VDDCORE—The ARM domain current is measured on R27 and the recommended

resistance value for this measurement is 0.02 Ohm.

>How did you average spike/ripples and include Table 8?

Using millivoltmeter, it has internal averaging circuit.

From AN4509 sect.2.5 "Hardware and Software Used":

The measurements were performed using Agilent 34401A6  Digit Multimeter.

Best regards

igor

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[keitanagashima]

Dear Igor,

Thank you for your reply.

I'd like to know how to measure the Maximum Supply currents by using Agilent 34401A6 Digital Multimeter.

(What is sampling frequency? Sampling count?)

I think that you cannot use the function of "Max hold" and "VDI".

Best Regards,

Keita

[igorpadykov]

Hi Keita

sampling frequency and sampling count do not matter

since these are low changing (actually DC) measurements.

>I think that you cannot use the function of "Max hold" and "VDI".

Sorry I do not know what is "Max hold" and "VDI".

Best regards

igor

[keitanagashima]

Hi Igor,

Do you know the sampling period and count?

For example, when freescale measured the max current consumption with COREMARK or 3D Mobile, how did you decide the data sheet max current value? And how did you measure it?

I think that the current consumption changes according to the load.

So, which timing did you measure the max current?

> Sorry I do not know what is "Max hold" and "VDI".

Sorry, it was typo.

Please ignore this question.

Best Regards,

Keita

[igorpadykov]

Hi Keita

sorry I do not know sampling period, count

and other details of measuring the max current.

I think you can create new thread for this.

Best regards

igor

[keitanagashima]

Dear Igor,

Hello. OK. Thank you very much!

Best Regards,

Keita