Описание
The ISL6291-2 provides a low-cost integrated charger solution for single-cell Li-ion and Li Polymer rechargeable batteries. No external pass element, current sensing resistor, or reverse blocking diode is required with this solution. The ISL6291-2 is a constant-current (CC)/constant-voltage (CV) charger. The constant charge current is programmable up to 2.0A with an external signal resistor. An internal trimmed current-sense circuit guarantees 10% accuracy, with no bulky external current-sense resistor. The constant voltage is either 4.1V or 4.2V. The charger always preconditions the battery with 1/10 of the programmed charge current at the beginning of a charge cycle, until it verifies that the battery can be fast-charged. A safety timer prevents over-charging a dead battery. The charging terminates as the charge current falls below the programmed minimum current during the CV mode. The charger automatically re-charges the battery when the battery voltage drops below a recharge threshold. A simple interface with an NTC thermistor avoids charging the battery outside a programmable temperature window. A thermalfoldback feature of the ISL6291-2 guarantees safe operation when the printed circuit board space is limited for thermal dissipation. The charger reduces the charge current automatically, as the internal temperature rises above a preset level, to prevent further temperature rise. When the wall adapter is not present, the ISL6291-2 draws less than 1µA current from the battery. Two logic outputs provide the charging status and fault information, and an easy interface to system logic. A V2P8 pin outputs a 2.8V reference voltage that can be used to bias other circuits, or as an indication for the adapter presence. The ISL6291-2 is packed in a thermally enhanced 5×5 QFN package. See the Technical Brief TB389 given in the Related Literature for more information related to the package.
- Integrated Linear Pass Element
- Integrated Charge Current Sensor
- No External Reverse Blocking Diode Required
- 1% Voltage Accuracy
- Programmable Current Limit Up to 2.0A
- Programmable End-of-Charge Current
- Trickle Charge an Over Discharged Battery
- Charge Current Thermal Foldback
- Simple Interface for Low-Cost Thermistor
- Accepts USB Bus Power
- Ambient Temperature Range: -20°C to 70°C
- Thermally-Enhanced 5×5 QFN Package (?JA = 33°C/W)
- Pb-Free Available (RoHS Compliant)
