App note: FT93x RTC external power switch circuit

App note from FTDI/Bridgetek on simple implementation of external power switch for RTC power hand-over. Link here (PDF)

The Texas Instruments SN74AUC2G53 Single-Pole Double-Throw (SPDT) analog switch is used to select the power supplied by the 1.5V battery or by the 1.2V internal LDO.

from Dangerous Prototypes