The bq24200EVM is an evaluation tool for the bq24200 500-mA single-cell Li-Ion charger. The bq2420x works with a current-limited, wall-mount transformer and therefore does not provide any current regulation. However, these devices offer a fixed internal current limit to prevent damage to the internal powerFET. A time-limited preconditioning phase conditions deeply discharged cells.
Once the battery reaches the charge voltage, the voltage-regulation loop takes over and completes the charge cycle. Charge is terminated on the basis of minimum current. An internal charge timer provides a backup safety for charge termination.