U1 is a TPS2113APW power multiplexer from Texas Instruments. It's a component used for automatic power source switching.

The TPS2113APW seems to fulfill its function based on the information provided. However, if you need a replacement, you may choose for similar components from different manufacturers for variety, or you may want to opt for components with enhanced features.

One suitable replacement could be the LTC4412 Low Loss PowerPath Controller from Linear Technology. This component provides nearly identical functionality with low loss switching between power sources.

Remember, you should verify the compatibility of the suggested replacement in terms of package type, pin configuration, and electrical characteristics with your existing design.

Here are it's significant features:

But note that while the electrical characteristics of the replacement part might be similar, it may have a different footprint or pin numbering that needs be reflected in your schematic and PCB layout. Please confirm its datasheet before you make a decision.