Linear Technology Corp. (LTC, Milpitas, CA) introduced the LTC4007, a standalone, full-featured, 4A, lithium-ion, battery pack charger with operating efficiencies as high as 96 percent. The LTC4007 is a step-down battery charger that drives external MOSFETs synchronously to achieve high efficiency. The IC is suitable for charging three-cell or four-cell lithium-ion battery packs from input voltages ranging from 6V to 28V.
As a microcontroller-independent charger, the LTC4007 integrates all the functions for charging control, termination, temperature monitoring and battery conditioning as well as status and fault reporting. The IC's high switching frequency of 300kHz reduces the size of inductor and capacitors for a compact design solution, which occupies only 5.6cm². Application examples include battery charger cradles, uninterruptible power supplies, portable data terminals and notebook PCs.
The LTC4007's charging current is programmable to ±5 percent accuracy. The preset float voltages are accurate to ±0.8 percent. The LTC4007 features a current-limiting function, which maximizes the charge rate without overloading the ac/dc adapter while the end product is in operation. The LTC4007 also includes a thermistor input, which suspends charging if an unsafe temperature condition is detected. For simple setup, the output float voltage is pin-programmable for cell counts of three or four cells and cell voltages of 4.1V or 4.2V.
The LTC4007 is offered in a 24-pin SSOP package. Pricing starts at $3.80 each for 1,000-piece quantities.
