Switching Battery Charger with Cascaded Two Loop Control Using Time-Based Techniques

This paper presents a Lithium-ion battery switching charger control chip with cascaded two loop time-domain controller. The proposed time-domain controller achieves seamless transition between constant-current (CC) mode and constant-voltage (CV) mode, and simplifies the controller design. The proposed switching charger control chip is designed and fabricated in TSMC 0.18 μm BCD technology. The input voltage range is from 5 V to 10 V, the battery voltage range is from 2.7 V to 4.2 V and the maximum charging current is 2.0 A. Measured results show that the proposed charger achieves maximum power efficiency of 93.3% at 1.0 A of charging current.