A 1.5A 88.6 Li-ion Battery Charger Design using Pulse Swallow Technique in Light Load

摘要

Traditional Li-ion battery chargers face a dilemma, which is the poor efficiency at a large charging current or vice versa. A pulse swallow technique is proposed in this investigation to resolve the mentioned problem. The proposed design carries out the automatic switching of PWM/PFM when the charging operation enters a light load scenario. When the battery voltage is close to the pre-defined full voltage, PFM strobes mask out the system clock to shut off power transistors to boost the efficiency. Post-layout simulations justify the proposed design generates 1.5 A current with 87.4%-88.6% efficiency.