Research And Design Of Intelligent Li-ion Battery Charger XD0818

Based on the project of “Theoretical research and design of Li-Ion BatteryCharger”, an intelligent Li-Ion battery charger XD0818is designed for digital cameras,mobile phones and other portable electronic products.XD0818is a linear charger, which can deliver up to1A of programmable chargecurrent. The charger has three phases of charging: pre-charge, constant current chargingand constant voltage charging. By controlling the gate voltage of PMOS powertransistor through the competence of multiple control loops, the circuit fulfills theconstant-current, constant-voltage and thermal regulation charge modes, and the smoothtransitions between them. The charger can check to see if a battery is present and allowprogramming of termination current. In addition, the charger also comes with a full setof safety features: JEITA (Japan Electronics and Information Technology Association)Temperature Standard, the input undervoltage/overvoltage protection, Safety timer, thebattery short/overvoltage protection. XD0818can automatically detect the state ofcharging information and make the appropriate adjustments.The chip was implemented using0.5μm CMOS process. Simulation and testresults show that the constant current accuracy is within4%, and constant voltageaccuracy is within0.5%; the other electrical indicators and protection functions are metwith the design requirements.