Switch-Mode 1-Cell Li+ Chargers
Smallest, Simplest Switch-Mode Li+ Charger in 4mm x 4mm QFN Package
DescriptionThe MAX1925/MAX1926 single-cell lithium-ion (Li+) switch-mode battery chargers use an external PMOS pass element step-down configuration. Charge current is programmable, and an external capacitor sets the maximum charge time.
Additional features include automatic input power detection (active-low ACON output), logic-controlled enable, and temperature monitoring with an external thermistor. The MAX1925 disables charging for inputs greater than 6.1V, while the MAX1926 charges for inputs between 4.25V and 12V.
The MAX1925/MAX1926 feature two precondition levels to restore near-dead cells. The devices source 4mA to a cell that is below 2V while sourcing C/10 to a cell between 2V and 3V. Full charge current is then applied above 3V. A active-low CHG output drives an LED to indicate charging (LED on) and fault conditions (LED blinking).
The MAX1925/MAX1926 are available in a 12-pin 4mm x 4mm thin QFN package and are specified over the extended temperature range (-40°C to +85°C). An evaluation kit is available to speed design.
- Cradle Chargers
- Digital Still Cameras
- Self-Charging Battery Packs
|Part Number||Lithium Ion Cells||Protected VIN|
|Charge Rate Set by||Max. ICHG|
|Charge Termination||Charge Regulation||Oper. Temp.|
|MAX1925||1||12||12||Resistor||2||Timer||Switchmode||-40 to +85|
MAX1926EVKIT: Evaluation Kit for the MAX1925, MAX1926
Technical DocumentsTutorial 680 How to Design Battery Charger Applications that Require External Microcontrollers and Related System-Level Issues
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
- Optimized Feature Set for Supercapacitor Charging
- Reliable Operation in Adverse Environmental Conditions
- Up to 16V Protection
- 13.7V Maximum Input Operating Voltage
- 3.15A Maximum Charging Current
- 3.5V to 23V Input Operating Range, 30VDC Withstand Voltage
- Reverse Leakage Protection
- 50mA to 3.15A Programmable Input Current Limit
- Battery Health + Programmable Safety/Protection
- ModelGauge m5 EZ Algorithm
- Precision Measurement Without Calibration
- AEC-Q100 Grade 2 Temperature Range
- Operating Voltage from 9V to 65V
- Ultra-Low-Power Operation