WP7607 SDIO voltage levels

HI, I would like to connect to the SDIO bus a Wi-Fi module that works at 1.8V.
Currently the WP7607 SDIO bus voltage is 2.8V.

How to configure the WP7607 to use SDIO bus at 1.8V


Hi ymark

Providing power for this interface with 1.8V to use SDIO bus at 1.8V

Please refer to page 101 in AirPrime_WP76xx_Product_Technical_Specification_Rev11_0.pdf
4.13 Secure Digital IO (SDIO) Interface
The AirPrime WP76XX module defines a 1.8 V/2.85 V SDIO interface
(SD 2.0-compliant) for customer-defined use with SD cards, connection to a Wi-Fi
module, etc.
Note: An external 1.8 V/2.85 V supply is required to supply power to the SD card.

You can get this document at here:
AirPrime_WP76xx_Product_Technical_Specification_Rev11_0.pdf (2.4 MB)

Please help to mark “Solution” if your question is answered

Hi Donald,

My question is about the SDIO signal voltage levels.
The Wi-Fi module is supplied with 1.8V and the SDIO signals voltage is also 1.8V
However the WP7607 SDIO signals voltage is 2.8V

My question is how to configure the WP7607 so that the SDIO signals voltage is also 1.8V


Hi ymark

You need to buy a resistor bridge to lower voltage 2.8v to 1.8v

You can contact FTDI to buy it.
E-Mail (Sales) : sales1@ftdichip.com E-Mail (Support) : support1@ftdichip.com E-Mail (General Enquiries) : admin1@ftdichip.com
Website URL : http://www.ftdichip.com

HI Donald,

That is something I already know, a beter solution is level shifter or using 2.8V regulator for the IO voltage of the Wi-Fi module

BUT, according to the datasheet :

The SDIO data lines has two levels 1.8V/2.8V
1 - is the datasheet wrong?
2 - if not there must be a way to tell the WP7607 to use SDIO data signals at 1.8V, in this case my question is how?

Hi ymark

The level of SDIO IO pin is by negotiated, you can change it in Yocto source to fix the voltage at 1.8v.
Please report your ticket to the Legato forum for more assistance in this case.

HI Donald,


I’ll continue to Legato forum