Bi-directional switches protect 1-cell and 2-cell lithium batteries on charge

The new DMN2014LHAB and DMN2011UFX dual N-channel enhancement mode MOSFETs, from Diodes Incorporated, provide a compact, bi-directional low-loss switch 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, the 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) < 13mO and < 9.5mO 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 tiny 2mm x 3mm DFN2030 package and the DMN2011UFX is offered in the 2mm x 5mm DFN2050, providing small form-factor solutions that allow designers to use the space saved for additional cells and increase the battery’s mAh capacity, says the company.