New Industry Products

Maxim Offers Single-Chip Lithium-Ion Protector For 5- To 10-Cell Battery Packs

October 22, 2008 by Jeff Shepard

Maxim Integrated Products introduced the DS2726, described as the industry’s most comprehensive stand-alone protection IC with integrated cell balancing for 5- to 10-cell lithium-ion (Li+) battery packs. Described as the only solution on the market that combines voltage and current monitoring with cell balancing in a single chip, the DS2726 is said to provide a space-saving solution for battery-operated devices. It is thus a suitable protector for power tools, e-bikes, portable household appliances, battery-backup systems, or any application with a 5- to 10-cell Li+ battery pack.

The DS2726 employs high-side p-channel protection FETs to provide comprehensive overvoltage, undervoltage, discharge-current, and short-circuit protection. The protection circuit monitors individual cell voltages to detect overvoltage and undervoltage conditions. Additionally, high-side protection allows the host system to maintain communication with a fuel gauge, such as the DS2788, even when a fault condition causes the protection FETs to switch off.

According to the company, to further simplify design and reduce cost, the DS2726 eliminates the need for an external microcontroller to configure the device. Voltage-protection and cell-balancing thresholds are pin programmable; overdischarge and short-circuit current limits are set with external resistors; and overdischarge and short-circuit current time-out delays are set with external capacitors. This simple device is thus said to provide robust protection while extending battery life by ensuring that all cells are equally charged. During cell balancing, internal switches shunt 150mA (typ) of current. For added flexibility, cell balancing can be enabled automatically on detection of a charger or by signaling a control pin.

The DS2726 is available in a space-saving, 7 x 7mm, 32-pin TQFN package. Prices start at $4.58 (1000-up, FOB USA).