The LTC4066/LTC4066-1 include a standalone constantcurrent/constant-voltage linear charger for single cell Li-ion batteries. The float 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 currents 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 float voltage, automatic recharging of the battery occurs. Also featured is an NTC thermistor input used to monitor battery temperature while charging. The LTC4066/LTC4066-1 are available in a 24-pin thin profile (0.75mm) 4mm x 4mm QFN package. The LTC4066 is also available in a 24-pin ultrathin profile (0.55mm) 4mm x 4mm UTQFN package.