We're looking for a device to interface to SD 3.0 cards at 1.8/3.3V. Most of the devices intended for this application (i.e. IP4856CX25) are 0.4mm BGAs that are difficult to work with. It looks like 2 x SN74AXC4T774 could work, though we'd need an external switch to change Vccb from 1.8 to 3.3V. We don't need to go to 208MHz... 100MHz or even 50MHz max clock speed would be ok.
Is it ok to switch Vccb on the SN74AXC4T774 once the part is operating? Vcca would be fixed at either 1.8 or 3.3V.
Is there another part we should consider for this application?
