BQ24650RVAT

• Maximum Power Point Tracking (MPPT) capability by inputVoltage regulation
• Programmable MPPT setting
• 5-V to 28-V Input solar panel
• 600-kHz NMOS-NMOS Synchronousbuck controller
• Resistor programmable floatvoltage
• Accommodates Li-Ion/Polymer, LiFePO4, lead acidchemistries
• Accuracy
  • ±0.5% Charge voltageregulation
  • ±3% Charge current regulation
  • ±0.6% Inputvoltage regulation
• HighIntegration
  • Internal loop compensation
  • Internal digitalsoft start
• Safety
  • Inputovervoltage protection
  • Battery temperature-sensing
  • Batteryabsent detection
  • Thermalshutdown
• Charge status outputs for LED or hostprocessor
• Charge enable on MPPSET pin
• Automatic sleep modefor low power consumption
  • < 15-μA OFF-state battery dischargecurrent
• Small 3.5 × 3.5mm2 16-pin QFN package

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The BQ24650 device is a highly integrated switch-mode battery charge controller. Itprovides input voltage regulation, which reduces charge current when input voltage falls below aprogrammed level. When the input is powered by a solar panel, the input regulation loop lowers thecharge current so that the solar panel can provide maximum power output.

The BQ24650 offers a constant-frequency synchronous PWM controller with high accuracycurrent and voltage regulation, charge preconditioning, charge termination, and charge statusmonitoring.

The BQ24650 charges the battery in three phases: pre-conditioning, constant current, andconstant voltage. Charge is terminated when the current reaches 1/10 of the fast charge rate. Thepre-charge timer is fixed at 30 minutes. The BQ24650 automatically restarts the charge cycle if thebattery voltage falls below an internal threshold and enters a low quiescent current sleep modewhen the input voltage falls below the battery voltage.

The BQ24650 supports a battery from 2.1 V to 26 V with VFB set to a 2.1-V feedbackreference. The charge current is programmed by selecting an appropriate sense resistor. The BQ24650is available in a 16 -pin, 3.5 mm × 3.5 mm2 thin QFN package.