Can the built-in regulator in iMX287 support maximum operating frequency?

[george]

Dear All,

We calculated the power consumption for designing our board.

Because inconsistency arose, I want someone to solve the riddle.

a)  Based on the data sheet, the maximum output current of DCDC_VDD is 250mA(MIN).

b)  When a Core clock is 454.73MHz according to i.MX28 Power Consumption Caliculator, the power consumption of Core is 408.43mW and the current is 263.5mA ( = 408.43mW / 1.55V ).

When the clock of Core is the maximum, can't needed current be supplied to Core only by a built-in regulator?

Is the supply from the outside needed?

Please let me know what kind of way of thinking is correct.

Best Regards,

George

[igorpadykov · Accepted solution]

Hi George

yes, it can be supplied to core only by a built-in regulator

if satisfied footnote 5 :

"The DCDC Converter is a triple output buck converter. The maximum output current capability of each output of the converter

is dependent on the loads on the other two outputs. For a given output, it may be possible to achieve a maximum output current

higher than that specified by ensuring the load on the other outputs is well below the maximum."

Also i.MX28 Power Consumption Caliculator is not very accurate tool,

real measurement i.MX28 EVK VDD current at high load = 235mA,

454MHz 800x480 Video Playback, DDR2 frequency = 200MHz

Best regards

chip

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[george]

Dear chip,

Thank you, I understood.

Best regards,

George