availability of 1.8V sd card interface with nRF52840

RE: availability of 1.8V sd card interface with nRF52840

Jared — Thu, 12 Jan 2023 08:26:53 GMT

Hi,

Ok, I don't really have that much experience with SD card. But if you supply the board with 1V8 then you can't get 3V3 on the GPIO peripheral. You would either have to use an external level shifter or increase the voltage supply.

regards

Jared

RE: availability of 1.8V sd card interface with nRF52840

sangyun Kim — Thu, 12 Jan 2023 05:44:32 GMT

Hi Jared.

I got the below command regarding USH-I bus mode 3.3V support is also mandatory to control SD spec.

SD memory cards have used a 3.3V signaling interface since the SD standard was introduced in 2000 and through SD Specification 3.0, when 1.8V signaling was added with the UHS-I bus mode, the ultimate removable single-ended interface. UHS-I adopted 1.8V signaling because it is suitable for faster rise/fall time and lower electromagnetic interference. However, UHS memory cards still require 3.3V signaling to initialize the card so hosts need to support 3.3V signaling, too.

RE: availability of 1.8V sd card interface with nRF52840

Jared — Wed, 11 Jan 2023 15:32:02 GMT

Seems like 1V8 is ok for this SD card:

RE: availability of 1.8V sd card interface with nRF52840

sangyun Kim — Wed, 11 Jan 2023 00:48:35 GMT

MicroSD PRO Endurance | Memory Card | Specs & Features | Samsung Semiconductor Global

we will use this micro sd card for this interface.

RE: availability of 1.8V sd card interface with nRF52840

Jared — Tue, 10 Jan 2023 12:50:44 GMT

Hi,

So the VDD of the nRF52840 is 1V8 and you're wondering if the SD card will work with GPIOs at 1V8?

Well, that would depend on the SD card. What is specified in the datasheet of the SD card?

regards
Jared