VA7205 Datasheet | Vimicro

FEATURES Ideal for Single (4.2V) Li-ion or Li-Polymer Packs - Better Than ±1% Voltage Regulation Accuracy With Preset Voltage .. - Adjustable precharge current with an external resistor - Adjustable Charging Current During Constant Current Charging Stage - Constant Voltage Charging - Automatic Battery-Recharge Feature - Cell-Temperature Monitoring Before and During Charge - Dynamic pensation of Battery Pack’s Internal Impedance to Reduce Charge Time - Charge Status Output for Dual Led - Cell Condition Monitoring - Automatic Low-Power Sleep Mode When Vcc is Removed or When Voltage Supply is Lower than battery voltage - Requires Small Number of External ponents - Packaging: 8-Pin SOP or MSOP - condition the battery. The conditioning charge rate can be adjusted with an external resistor. After the battery is precharged to Vmin, the VA7205 applies a constant current to the battery. An external sense-resistor sets the current. The constant-current phase continues until the battery reaches the charge-regulation voltage (normally at 4.2V) and then the VA7205 begins the constant-voltage phase. The accuracy of the voltage regulation is better than ±1% over the operating-temperature and supply-voltage ranges. Under this stage the charging current will gradually decrease. Charge stops when the current tapers to the charge termination threshold, ITERM. The VA7205 will continue monitoring the battery voltage level and entering a new cycle of charging if the battery’s voltage level has fell below VRECHG (normally at VREG 125m V). During the charging process, for the safety concern, the VA7205 continuously measures battery temperature using the battery’s internal heat sensitive resistor and an external resistors. If the temperature of the battery exceeds the pre-set temperature range, the charging process will e to a halt after 0.5 seconds; After the temperature fell back into the pre-set temperature range, the charging will continue again after 0.5 seconds. The VA7205 can also...