Product details


Number of series cells 1 Charge current (Max) (A) 0.1 Operating Vin (Max) (V) 5.1 Cell chemistry Li-Ion/Li-Polymer, SuperCap Battery charge voltage (Min) (V) 2.2 Battery charge voltage (Max) (V) 5.5 Absolute Vin (safety rating) (Max) ((V)) 5.5 Control interface Standalone (RC-Settable) Features Input OVP, Solar input/MPPT Operating Vin (Min) (V) 0.6 Rating Catalog open-in-new Find other Battery charger ICs

Package | Pins | Size

VQFN (RGR) 20 12 mm² 3.5 x 3.5 open-in-new Find other Battery charger ICs


  • Ultra Low-Power With High-Efficiency DC-DC Boost Charger
    • Cold-Start Voltage: VIN ≥ 600 mV
    • Continuous Energy Harvesting From Input Sources as Low as 100 mV
    • Ultra-Low Quiescent Current of 325 nA
    • Input Voltage Regulation Prevents Collapsing High-Impedance Input Sources
    • Ship Mode With < 5 nA From Battery
  • Energy Storage
    • Energy can be Stored to Rechargeable Li-Ion Batteries, Thin-Film Batteries, Super-Capacitors, or Conventional Capacitors
  • Battery Charging and Protection
    • Internally Set Undervoltage Level
    • User-Programmable Overvoltage Level
  • Battery-Good Output Flag
    • Programmable Threshold and Hysteresis
    • Warn Attached Microcontrollers of Pending Loss of Power
    • Can be Used to Enable or Disable System Loads
  • Programmable Maximum Power Point Tracking (MPPT)
    • Integrated MPPT for Optimal Energy Extraction From a Variety of Energy Harvesters
  • Gate Drivers for Primary (Nonrechargeable) and Secondary (Rechargeable) Storage Element Multiplexing
    • Autonomous Switching Based on VBAT_OK
    • Break-Before-Make Prevents System Rail Droop
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The bq25505 device is specifically designed to efficiently extract the microwatts (µW) to miliwatts (mW) of power generated from a variety of DC energy harvesting, high-impedance sources like photovoltaic (solar) or thermal electric generators (TEGs) without collapsing those sources. The battery-management features of the bq25505 ensure that a secondary rechargeable battery is not overcharged by this extracted power, with voltage boosted, nor depleted beyond safe limits by a system load. The integrated multiplexer gate drivers autonomously switch the system load to a primary nonrechargeable battery if the secondary battery voltage falls below the user-defined VBAT_OK threshold.

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Technical documentation

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Software development

SLUC463A.ZIP (31 KB)

Design tools & simulation

SLUC484.ZIP (284 KB)

Reference designs

Energy Harvesting Ambient Light and Environment Sensor Node for Sub-1GHz Networks Reference Design
TIDA-00488 TIDA-00488 demonstrates an ultra-low power and a renewable method of wireless environmental sensing using daylight energy harvesting with a long backup battery life. This reference design uses our ultra-low power harvester power management SimpleLink™ ultra-low power sub-1 GHz wireless (...)
document-generic Schematic
Energy Harvesting and Fault Indicator Subsystem for Overhead Fault Indicators Reference Design
TIDA-00998 — This reference design shows multiple architectures for extending primary battery life using a secondary battery or supercapacitor with energy harvested from a current transformer (CT) or solar cells. Optimal power management is done using efficient LED drivers to drive series or parallel (...)
document-generic Schematic
Indoor Light Energy Harvesting Reference Design for Bluetooth Low Energy (BLE) Beacon Subsystem
TIDA-00100 The Indoor Light Energy Harvesting Reference Design for Bluetooth Low Energy (BLE) Beacon Subsystem provides a solution where by with just the power of the typical indoor lighting in a retail environment (greater than 250 LUX) the Bluetooth Low Energy chip can broadcast BLE beacons.

This subsystem (...)

document-generic Schematic

CAD/CAE symbols

Package Pins Download
VQFN (RGR) 20 View options

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