The MAX1870AETJ step-up/step-down multichemistry battery charger charges with battery voltages above and below the adapter voltage. This highly integrated charger requires a minimum number of external components. The MAX1870AETJ uses a proprietary step-up/stepdown control scheme that provides efficient charging. Analog inputs control charge current and voltage, and can be programmed by the host or hardwired. The MAX1870AETJ accurately charges two to four lithiumion (Li+) series cells at greater than 4A. A programmable input current limit is included, which avoids overloading the AC adapter when supplying the load and the battery charger simultaneously. This reduces the maximum adapter current, which reduces cost. The MAX1870AETJ provides analog outputs to monitor the current drawn from the AC adapter and charge current. A digital output indicates the presence of an AC adapter. When the adapter is removed, the MAX1870AETJ consumes less than 1μA from the battery. The MAX1870AETJ is available in a 32-pin thin QFN (5mm x 5mm) package and is specified over the -40°C to +85°C extended temperature range. The MAX1870AETJ evaluation kit (MAX1870AEVKIT) is available to help reduce design time.
Feature
- Highly Flexible Input Voltage Range Works with Affordable AC Adapters
- Step-Up/Step-Down Control Scheme
- Input Voltage from 8V to 28V
- Analog Output Indicates Adapter Current
- Accurately Charge Li+ or NiCd/NiMH Batteries
- Battery Voltage from 0 to 17.6V
- ±0.5% Charge-Voltage Accuracy
- ±9% Charge-Current Accuracy
- ±8% Input Current-Limit Accuracy
- Tune Design to Increase Safety and Efficiency
- Programmable Maximum Battery Charge Current
- Analog Inputs Control Charge Current, Charge Voltage, and Input Current Limit
- 32-Pin Thin QFN (5mm x 5mm) Package Saves Space While Supporting Step-Up and Step-Down Operation
Applications
- Handheld Terminals
- Notebook and Subnotebook Computers
