Linear Technology Corp. (LTC, Milpitas, CA) introduced the LTC4006, a two-cell to four-cell, lithium-ion (Li-Ion) battery charger with up to 4A charge capability that includes essential I/O status signals required for constructing a simple, autonomous, high-power, battery charger system. The LTC4006 is housed in a narrow, 16-pin, SSOP package and offers output signals for end-of-charge and wall-adapter detection, as well as a charge current value indicator for gas-gauging. The IC's synchronous, dc/dc, step-down operation allows up to 96% operating efficiency from supplies from 6V to 28V supplies.
The LTC4006 can operate at up to 98% duty factor, which permits 0.5V dropout operation and allows charging from low-voltage wall adapters. To improve safety during charging, the LTC4006 features a battery temperature monitor as well as over-voltage and over-current protection. End applications include memory backup systems, portable medical and automotive diagnostics, global positioning systems, as well as notepad and notebook PCs.
The LTC4006 features a quasi-constant frequency, and constant off-time architecture that does not generate audible noise even when using ceramic capacitors. The IC is offered in three versions for 8.4V (two-cell), 12.6V (three-cell) and 16.8V (four-cell) float voltages with ±0.8% accuracy. Charging current is programmable with a resistor to ±4% typical accuracy. For gas gauging, a proprietary feature represents the charging current as a voltage to a microcontroller or an analog-to-digital converter. A resistor sets total charge time from one to three hours. The LTC4006 includes automatic recharge and trickle charging.
The LTC4006 operates from -40°C to +85°C and is priced at $3.60 each for 1,000-piece quantities.
