• High-Efficiency Switched-Mode Charger With Separate Power Path

• Startup System From Deeply Discharged or Missing Battery

• USB Charging Compliant

• Selectable Input Current Limit of 100 mA, 500 mA, 900 mA, 1.5 A, and 2 A

• BC1.2 Compatible D+, D– Detection

• In Host Mode (After I2C Communication Starts and Before Watchdog Timer Times Out)

• Programmable Battery Charge Voltage, VBATREG

• Programmable Charge Current (ICHG)

• Programmable Input Current Limit (ILIM)

• Programmable Input Voltage-Based Dynamic Power Management Threshold, (VIN_DPM)

• Programmable Input Overvoltage Protection Threshold (VOVP)

• Programmable Safety Timer

• Resistor Programmable Defaults for:

• ICHG up to 2 A With Current Monitoring Output (ISET)

• ILIM up to 2 A With Current Monitoring Output (ILIM)

• VIN_DPM (VDPM)

• Watchdog Timer Disable Bit

• Integrated 4.9 V, 50 mA LDO

• Complete System-Level Protection

• Input UVLO, Input Overvoltage Protection (OVP), Battery OVP, Sleep Mode, VIN_DPM

• Input Current Limit

• Charge Current Limit

• Thermal Regulation

• Thermal Shutdown

• Voltage-Based, JEITA Compatible NTC Monitoring Input

• Safety Timer

• 22 V Absolute Maximum Input Voltage Rating

• 10.5 V Maximum Operating Input Voltage

• Low RDS(on) Integrated Power FETs for a Charging Rate of up to 2 A

• Open-Drain Status Outputs

• Synchronous Fixed-Frequency PWM Controller Operating at 3 MHz for Small Inductor Support

• AnyBoot Robust Battery Detection Algorithm

• Charge Time Optimizer for Improved Charge Times at Any Given Charge Current

• 2.40-mm × 2.00-mm 30-Ball DSBGA and 4-mm × 4-mm 24-Pin QFN Packages

The bq24250, bq24251, and bq24253 are highly integrated single-cell Li-Ion battery chargers and system power-path management devices targeted for space-limited, portable applications with high-capacity batteries. The single-cell charger has a single input that operates from either a USB port or an AC wall adapter for a versatile solution.

The power-path management feature allows the bq24250, bq24251, and bq24253 to power the system from a high-efficiency DC-DC converter while simultaneously and independently charging the battery. The charger monitors the battery current at all times and reduces the charge current when the system load requires current above the input current limit. This reduced charge current allows for proper charge termination and enables the system to run with a defective or absent battery pack. Additionally, this reduced charge current enables instant system turnon even with a totally discharged battery or no battery. The architecture of the power-path management also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents. This supplementation of current requirements enables the use of a smaller adapter.

The battery is charged in four phases: trickle charge, precharge, constant current, and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the internal temperature threshold is exceeded. Additionally, a voltage-based, JEITA compatible battery pack thermistor monitoring input (TS) that monitors battery temperature for safe charging is included.