SD card power consumption

[stenlik]

Hello,

I have a question related to the (micro)SD card power consumption. What are
the
typical power consumption values? I think that it depends on card
manufacturer,
card storage size, speed, etc. I have found that from the CSD register I
can read the max. and min. values for power consumptions (VDD_R_CURR_MIN,
VDD_W_CURR_MIN, VDD_R_CURR_MAX and VDD_W_CURR_MAX) for read and write
operations. Those values I think should be less then 100ma, typically about
50 mA, plus the power consumption depends also on the voltage level on VDD,
which is between 2.7V and 3.6V. Am I right?

Regards,
STeN

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[Mark Borgerson]

In article <GsSdnf2Ap9IflWHX...@giganews.com>,
petr.m...@hotmail.com says...

> Hello,
>
> I have a question related to the (micro)SD card power consumption. What are
> the
> typical power consumption values? I think that it depends on card
> manufacturer,
> card storage size, speed, etc. I have found that from the CSD register I
> can read the max. and min. values for power consumptions (VDD_R_CURR_MIN,
> VDD_W_CURR_MIN, VDD_R_CURR_MAX and VDD_W_CURR_MAX) for read and write
> operations. Those values I think should be less then 100ma, typically about
> 50 mA, plus the power consumption depends also on the voltage level on VDD,
> which is between 2.7V and 3.6V. Am I right?
>
> Regards,
> STeN
>

I've been doing some tests recently with full-sized SDHC cards. I find
that there can be significant differences between 'normal' speed cards
and the high-speed cards. The normal cards have a peak current of
about 40mA when doing a write and the high-speed cards are about
60mA. If your processor is fast enough, I suppose that the overall
energy used is nearly equal, as you can get the data out to the
high-speed card more quickly. If your system is fast enough,
the high-speed cards may even have an advantage.

I'm using the cards in a low-power system based on an MSP430 with
a 14MHz clock rate, so my write speed is processor-limited. That
means I'm better off with the normal speed cards. However, those
are more difficult to find in the 16 and 32GB sizes, where the
marketing emphasis seems to be on their use for video or photo
storage and the devices can keep up with the higher speed ratings.

Mark Borgerson

[dawydiuk]

Hello,

>> I have a question related to the (micro)SD card power consumption. What
are
>> the
>> typical power consumption values?

I recently looked into this and found the spec allows an SDHC card to draw
up to 200 mA. Although, we've found measured some high speed SDHC cards
draw up to 450 mA.

Regards,
Eddie