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SD Card SPI mode always draws 20mA current

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verto

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sd card current consumption

I have a project which uses a SDCARD in SPI mode.

I have no problem interfacing with the card but as I want to use this project powered by batteries it draws to much current.

My system draws 23mA without the SD card inserted.
The moment I insert my SD card, the current rises up to 57 mA
After initialisation the current drops to 41 mA

When not using the card, I set the CS to high, but it doesn't change current consumption.
Anyone has an idea how to put the card in low power mode.
 

msp430 use a p channel fet as a switch

I think SD card hasn't power down mode, the better way is disconnect the power using a p channel mosfet for example.
 

spi mode

I have found what the problem was.
it was my own stupid mistake.

The SD card connector has also two switches to detect if the card is present and if the write-protect switch is enabled.
I connected these switches to 2 pins of my microcontroller.
I forgot to set the pin configuration to open-drain (it was still on push-pull).
Hence, when I inserted my card, the switches short-circuited the pin to ground and the pins were sourcing the max available current.

Now the sdcard uses only 10mA when writing and less than 1mA in standby.

thanks for the replies.
 

sd spi mode

Hello!

Although the issue seems to be closed, it may be worth to add that
the SD card DOES HAVE a low power mode, and I think it's part of the
SD standard (not sure of this one, but I have read about the low power
mode in Sandisk's documents anyway).

Dora.

leomecma said:
I think SD card hasn't power down mode, the better way is disconnect the power using a p channel mosfet for example.
Click to expand...
 

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