1-2 cell Li-ion/polymer fuel gauge on a 1-Wire bus
The DS2781G+: This is a battery monitor IC that tracks charge and discharge for one or two series-connected lithium-ion or lithium-polymer cells. The 1-Wire interface means the host communicates over a single data line plus ground, keeping the wiring simple in a portable device or battery pack. Operating temperature spans -20°C to 70°C, which covers indoor consumer and industrial environments but not automotive under-hood or extended cold storage. The part is ROHS3 compliant, so it meets current EU and global material restrictions without exemptions.
10-TDFN package — exposed pad rework notes
The DS2781G+ comes in a 10-lead WFDFN with an exposed pad, supplier package designation 10-TDFN (3x4 mm). The exposed pad on the bottom needs a thermal land on the PCB for heat sinking and electrical ground connection — a standard via-in-pad or solder-paste stencil opening around the centre pad helps avoid voids during reflow. The package ships in a Tube. For hand rework, the small 3x4 mm body and exposed pad are manageable with hot air at 300-350°C; the pad orientation is clear from the datasheet pinout. Will it survive the hot air? Yes — the TDFN has no internal cavity and the mould compound handles typical rework profiles without delamination, provided the board is preheated to 100°C to reduce thermal shock.