“This is another USB power management/battery charger IC from Linear and a follow-up to the LTC4066 displayed earlier. This seems like an earlier version of the same design, which makes sense, since the 4066 was from the iPhone while the 4055 is from a fourth generation iPod. The designs look similar, but we won’t fully know what changed until the datasheet for the LTC4066 is publicly available. The 10x stitch is of the whole chip while the 20x stitch is a closeup of the control electronics on the bottom of the chip.”

Source: http://microblog.routed.net/2007/11/09/ic-friday-linears-tlc4055/

Package

Die