The LTC4066/LTC4066-1 are USB power managers and Li-Ion battery chargers designed to work in portable battery-powered applications. The parts control the total current used by the USB peripheral for operation and battery charging. The total input current can be limited to 100mA, 500mA or "unlimited" (i.e., above 2A). Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the programmed input current limit. The LTC4066/LTC4066-1 include a standalone constant-current/constant-voltage linear charger for single cell Li-ion batteries. The ?oat voltage applied to the battery is held to a tight 0.8% tolerance, and charge current is programmable using an external resistor to ground. A programmable end-of-charge status output (CHRG) indicates full charge. BAT pin charge and discharge cur- rents can be monitored via an analog output (ISTAT). Total charge time is programmable by an external capacitor to ground. When the battery drops 100mV below the ?oat voltage, automatic recharging of the battery occurs. Also featured is an NTC thermistor input used to monitor bat- tery temperature while charging. The LTC4066/LTC4066-1 are available in a 24-pin thin pro?le (0.75mm) 4mm x 4mm QFN package. The LTC4066 is also available in a 24-pin ultrathin pro?le (0.55mm) 4mm x 4mm UTQFN package.
