topic Re: Inquiry i.MX28 VDDA maximum output current or min. current in i.MX Processors

Inquiry i.MX28 VDDA maximum output current or min. current

andychien — Thu, 30 Jan 2020 03:11:38 GMT

Dear Sir,

I have some confuse about table value is Min. or Max current on VDDA output.

Could you confirm it?

Thanks,

Re: Inquiry i.MX28 VDDA maximum output current or min. current

igorpadykov — Thu, 30 Jan 2020 04:39:13 GMT

Hi Andy

this is guaranteed output current, also one should pay attention to :

3 Because the internal linear regulators are cascaded, it is not possible to simultaneously operate the VDDIO, VDDA, VDDM, and VDDD linear regulators at the maximum specified load current. For example, the VDDIO linear regulator provides current to both the VDDIO 3.3 V supply rail as well as the VDDM and VDDA linear regulator inputs. Likewise, the VDDA linear regulator provides current to both the 1.8 V supply rail as well as the VDDD linear regulator input. The application designer should ensure the following two conditions are met:

(VDDIO Load Current + VDDM Load Current + VDDA Load Current) < VDDIO Maximum Output Current
(VDDA Load Current + VDDD Load Current) < VDDA Maximum Output Current

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.

Best regards
igor
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Re: Inquiry i.MX28 VDDA maximum output current or min. current

andychien — Thu, 30 Jan 2020 05:55:14 GMT

Dear Sir,

I understood those note information, but the table write parameter said DCDC_VDDA Maximum Output Current (VDDA =1.8V)= 200mA, but 200mA is put Min field.

Could you tell me the 200mA is Max value or Min value?
Thanks a lot,

Re: Inquiry i.MX28 VDDA maximum output current or min. current

igorpadykov — Thu, 30 Jan 2020 10:36:03 GMT

Hi Andy

"Max value or Min value" are not specified by datasheet.

You can consider Table 13 as "typical" current and it may vary

depending on currents on other outputs.

Best regards
igor

Re: Inquiry i.MX28 VDDA maximum output current or min. current

andychien — Thu, 30 Jan 2020 11:05:15 GMT

Dear Sir,

Sorry, I don't know your mean.

If customer measure VDDA output current (peak value) is 250mA~400mA, it mean over i.MX28 spec, right?

Thanks

Re: Inquiry i.MX28 VDDA maximum output current or min. current

igorpadykov — Thu, 30 Jan 2020 11:20:20 GMT

>If customer measure VDDA output current (peak value) is 250mA~400mA,

>it mean over i.MX28 spec, right?

right.

One can also try

i.MX28 Power Calculator spreadsheet

Best regards
igor