Regulator for micro SD card

Hi,

I want to insert a micro SD card to my PCB. the circuit is powered by a 3V Li-MnO2 battery.

I need to regulate the SD card to 2.7v.

all the circuit components are regulated by TPS78222DRVR (2.2v)

My Q's are-

1. what's the best way to regulate micro SD card: by dc-dc step down buck converter or by LDO?

2. the 2.2v output LDO will be located after the 2.7v  buck converter/ LDO. Is it make sense?

thanks in advance!

Ram