The Analog Devices ADP3806 is a stand-alone Li-Ion battery-charging IC that combines high output voltage accuracy with precise current control to improve the performance and reduce the design complexity of Constant-Current, Constant-Voltage (CCCV) chargers.
The industry’s highest end-of-voltage accuracy levels are achieved to within ±0.4% at 25ºC, ±0.6% at 5ºC to 55ºC and ±0.7% at 0ºC to 85ºC. The ship sports three selectable voltage options, programmable charge currents and programmable oscillator frequencies.
Functional integration includes automatic current sensing with reverse input protection, under voltage lockout and a bootstrapped synchronous drive for external NMOS FETs. (Synchronous operation provides high efficiency when charging at high current.) The ADP3806 is designed primarily for notebook PCs as well as fast chargers and handheld devices such as personal digital assistants (PDAs).
Three models of the ADP3806 offer adjustable battery voltages guaranteed to within ±0.6% of their specified value: the ADP3806-12.6 can be set to either 12.6 or 16.8 V, the ADP3806-12.5 can be either 12.525 or 16.7 V, and the adjustable version is useful for charging one- or two-cell Li-Ion batteries, or for custom Li-Ion cells.
As a battery approaches its final voltage, the ADP3806 switches from constant-current mode to constant-voltage mode. The on-board current sense amplifier accepts rail-to-rail inputs to ensure precise and controlled operation under low drop out and short circuit conditions.
All models of the ADP3806 are housed in a 24-lead TSSOP package, available on tape and reel and priced at $2.25 per unit in 10,000 piece quantities.