•The TPS61181A min input voltage lowered to 4.5V from 5V on the TPS61181 and

          - UVLO VIN rising: 4.5V max

          - UVLO VIN falling 4.0V min,

          - UVLO hysteresis: 200mV

•TPS61181A EN and DCTRL pins have

       -enhanced ESD protection

       - a 20V abs max rating instead of 7V on the '81

       - low/high threshold changed from 0.4/1.2V on the '81 to 0.8V/2.0V on the '81A.

•TPS61181 required that EN be held low for 32 ms before the IC would shutdown.  This delay has been removed on the TPS61181A.