An Adaptive DC-DC Converter for Loading Circuit of Li-Ion Battery Charger

In this paper, an adaptive output DC-DC converter designed for lithium-ion (Li-Ion) battery charger circuit is proposed. The converter operates in continuous conduction mode (CCM) to provide an output voltage in response to battery voltage and a wide-range output current to ensure that circuit requirements are met. This circuit is designed on Cadence using 0.35-mu m BCD technology. Simulation results show that the circuit fully operates in CCM mode with a load current from 50 mA to 1000 mA and output voltage ripple factor is less than 1%. Furthermore, the current supplied to the load circuit responses to three types of Li-Ion rechargeable currents. The output voltage of the converter varies from 2.8 V to 4.5 V corresponding to the voltage range of the battery being charged from 2.5 V to 4.2 V. The average power output of the converter in large load current mode (1000 mA) reaches 92.3%.