The LTC4095 is a complete constant-current/constantvoltage linear charger for single-cell lithium-ion/polymer batteries. Its small 2mm x 2mm DFN package and low external component count make the LTC4095 especially well-suited for portable USB power applications. Up to 950mA of charge current may be programmed via a single resistor from the PROG pin to ground. The HPWR pin allows the charge current to be set at 20% or 100% of its full-scale programmed value. An internal safety timer terminates charge current. The final float voltage is preset to 4.2V and held to a tight 0.5% tolerance. Also featured is an NTC thermistor input to monitor battery temperature while charging, a C/10 current detection output, automatic recharge, bad-battery detection and low-battery trickle charge. A thermal feedback loop regulates the charge current to limit the die temperature during high power operation or high ambient thermal conditions. The LTC4095 is available in a tiny, low profile (0.75mm) 8-lead 2mm × 2mm DFN package.
