In this paper, an integrated multimode battery charger in a Qi-compliant wireless power receiver is presented. The proposed wireless battery charger includes a synchronous rectifier circuit and a multi feedback low dropout regulator. The charging circuit automatically switches trickle current, constant-current, and constant-voltage mode corresponding to battery voltage. Through control of the target rectified voltage from the perspective of the wireless power receiver, the synchronous rectifier circuit can generate an adaptive rectified voltage to closely track the battery voltage, which significantly reduce the power loss in the charging circuit. The wireless battery charger was implemented with a TSMC 0.18 µm BCD 1P5M process and the experimental results show the charging current of constant-current mode is 1 A and the final voltage of the wireless battery charger is 4.2 V. The maximum efficiency of the overall system is 78%.

本文提出了在符合Qi标准的无线电力接收器中集成的多模式电池充电器。所提出的无线电池充电器包括同步整流器电路和多反馈低压差稳压器。充电电路会根据电池电压自动切换trick流电流，恒定电流和恒定电压模式。通过从无线电力接收器的角度控制目标整流电压，同步整流电路可以生成自适应整流电压以紧密跟踪电池电压，从而显着减少充电电路中的功率损耗。无线电池充电器由TSMC 0实现。