LTC4077

The LTC4077 is a standalone linear charger that is capable of charging a single-cell Li-Ion battery from both wall adapter and USB inputs. The charger can detect power at the inputs and automatically select the appropriate power source for charging.

No external sense resistor or blocking diode of LTC4077 is required for charging due to the internal MOSFET architecture.

Internal thermal feedback of LTC4077 egulates the battery charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions.

The float voltage is fi xed at 4.2V and the charge current is programmed with an external resistor. The LTC4077 terminates the charge cycle when the charge current drops below the termination threshold after the fi nal fl oat voltage is reached. The LTC4077 can be put into shutdown mode reducing the DCIN supply current to 20A, the USBIN supply current to 10A, and the battery drain current to less than 2A even with power applied to both inputs.

Other features of LTC4077 include automatic recharge, undervoltage lockout, charge status output, power present status output to indicate the presence of wall adapter or USB power and high power/low power adjustable mode for USB compatible applications.