Bidirectional Switches Protect 1-Cell and 2-Cell Lithium Batteries During Charging

Diodes, Inc. has introduced the DMN2014LHAB and DMN2011UFX. These dual N-channel enhancement mode MOSFETs provide compact, bi-directional low-loss switches for battery-charging circuits. End-markets include chargers for portable devices such as smartphones, tablets, cameras and media players, which use 1-cell and 2-cell lithium batteries.

The DMN2014LHAB and DMN2011UFX are configured as dual common-drain MOSFETs and, when switched on, these devices allow bi-directional current flow for charging or operational use. When switched off they protect the battery by preventing over-charging or excessive current drain. With a 20V breakdown rating, the DMN2014LHAB and DMN2011UFX also feature low on resistance, RDS(on) < 13mΩ and < 9.5mΩ, respectively, to reduce battery power loss in normal operation. A high maximum peak current up to 80A allows the switch to briefly handle short-circuit conditions before the protection circuitry kicks in, while a low gate threshold voltage (VGS(th) <1V) ensures correct operation even with drive voltages as low as 1.8V.

The DMN2014LHAB is available in the 2 mm by 3 mm DFN2030 package and the DMN2011UFX in the 2 mm by 5 mm DFN2050, providing small form-factor solutions that allow designers to use the space saved for additional cells and increase the battery’s mAh capacity.