The MAX6775LTA+T is supplied in a 6-WFDFN package (6-uDFN, 1.5x1 mm footprint). That 1.5 mm by 1 mm body is about as small as a six-pin DFN gets — the exposed pad under the package is the thermal and electrical ground path, so the PCB layout needs a solid via pattern under that pad to pull heat out of the die during continuous monitoring.
What the battery monitor does
This is a single-cell battery monitor that works with multiple chemistries — Li-ion, Li-Poly, NiMH, alkaline, you name it.