Linear Technology Develops LTC1732 Li-Ion Battery Charger
Linear Technology (Milpitas, CA) has developed the LTC1732, a linear battery charger for single-cell lithium-ion batteries. Featuring one percent charge-voltage accuracy, programmable charge current and charge termination, Linear Technology claims that the new constant-current constant-voltage chip is a complete charger.
The LTC1732 is designed to automatically detect and report the presence of the wall adapter and insertion of a new battery, thereby eliminating the need for external detection circuitry. A digital voltage selection input allows the chip to charge to either 4.1V or 4.2V. The company maintains that its programmable charge current achieves 7 percent accuracy.
Linear Technology claims that their new IC automatically trick-charges deeply discharged cells and enters sleep mode when the input supply is removed, dropping battery drain to 7microamps. It also detects end-of-charge conditions while a programmable timer, using an external capacitor, sets the total charge time.
NiCd and NiMH batteries can also be charged in the constant-current mode using external termination. The part is offered in a 10-lead miniature small-outline package. Pricing starts at $2.15 each in quantities of 1,000.
