The AAT4674/4674-1 are members of AnalogicTech’s Application Specific Power Management SmartSwitch™ family. These devices are dual input single output power supply selector switches designed to operate from batteries, or any other power supply with an input voltage up to 6V.
The AAT4674/4674-1 connects the supply voltage on IN1 to OUT, or IN2 to OUT, through a very low RDS(ON) power MOSFET that minimizes voltage drops and power dissipation. The enable (EN) and select (SEL) pin voltages control the operational state of the internal power MOSFET switches. Once enabled, the SEL pin will switch between the IN1 and IN2 inputs. If both input voltages are below the UVLO, then the AAT4674 output floats. In the case of the AAT4674-1, if one of the input voltages is above the UVLO threshold then that input voltage that is above the UVLO threshold is passed through to the output.