New single-input cell Li-Ion and Li-Pol battery charger with an auto start

Halo Microelectronics has released its HL7040C, a highly integrated family of 2mm x 2mm single-cell Li-Ion and Li-Pol linear chargers.

The device is excellent for portable applications, comprising smartphones, MP3 players, PDAs, and low-powered handheld devices with limited board space. It functions 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 charger has a single power output that charges the battery and a system load that may be placed in parallel with the battery as long as the average system load does not keep the battery from charging completely during the ten-hour safety timer.

As the battery is charged in three phases – pre-charge to recover a completely discharged battery, fast-charge constant current to supply the buck charge safely, and voltage regulation to reach full capacity safely –

an internal control loop monitors the IC junction temperature and decreases the charge current if an internal temperature threshold is exceeded.

The charger also has a full set of safety features, including the JEITA temperature standard, over-voltage protection, safety timers, DPM-In, and ISET short protection. The device is intended 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. Also, the pre-charge current, termination current threshold, and fast-charge current are all programmed through an external resistor.

“The new HL7040C features a 1% charge-voltage accuracy, a 10% charge-current accuracy, and a selectable 100mA/500mA input current with key protection. It also includes a programmable hot-fault threshold making the IC one-off from its competition, thus making it ideal for portable applications,” said David Nam, CEO of Halo Microelectronics.