The HL7040C is intended for portable applications, including smartphones, PDAs, MP3 players, and low-powered handheld devices with limited board space, as it operates from either a USB port or an AC adapter. The high-input voltage range with input over-voltage protection also supports low-cost unregulated adapters.
The device has a single power output that charges the battery, and a system load that can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10-hour safety timer.
As the battery is charged in three phases - pre-charge to recover a fully discharged battery, fast-charge constant current to supply the buck charge safely, and voltage regulation to safely reach full capacity - an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded.
The HL7040C also comes with a full set of safety features, including the JEITA temperature standard, over-voltage protection, DPM-In, safety timers, and ISET short protection.
The device is designed for a single-power path from the input to the output to charge a single-cell Li-Ion or Li-Pol battery pack.
In the charger-power stage with the charger-current sense functionally integrated, the charger function has a high-accuracy current, and the voltage regulation loop charge display and charge termination. In addition, the pre-charge current, termination current threshold, and fast-charge current are all programmed via an external resistor.
