1 Features
1• Ultra Low Power DC-DC Boost Charger
– Cold-Start Voltage: VIN ≥ 600 mV
– Continuous Energy Harvesting From VIN as
low as 100 mV
– Input Voltage Regulation Prevents Collapsing
High Impedance Input Sources
– Full Operating Quiescent Current of 488 nA
(typical)
– Ship Mode with < 5 nA From Battery
• Energy Storage
– Energy can be Stored to Re-chargeable Li-ion
Batteries, Thin-film Batteries, Supercapacitors,
or Conventional Capacitors
• Battery Charging and Protection
– Internally Set Undervoltage Level
– User Programmable Overvoltage Levels
• 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 Step Down Regulated Output
(Buck)
– High Efficiency up to 93%
– Supports Peak Output Current up to 110 mA
(typical)
• Programmable Maximum Power Point Tracking
(MPPT)
– Provides Optimal Energy Extraction From a
Variety of Energy Harvesters including Solar
Panels, Thermal and Piezo Electric Generators

2 Applications
• Energy Harvesting
• Solar Chargers
• Thermal Electric Generator (TEG) Harvesting
• Wireless Sensor Networks (WSN)
• Low Power Wireless Monitoring
• Environmental Monitoring
• Bridge and Structural Health Monitoring (SHM)
• Smart Building Controls
• Portable and Wearable Health Devices
• Entertainment System Remote Controls

3 Description
The bq25570 device is specifically designed to
efficiently extract microwatts (μW) to milliwatts (mW)
of power generated from a variety of high output
impedance DC sources like photovoltaic (solar) or
thermal electric generators (TEG) without collapsing
those sources. The battery management features
ensure that a rechargeable battery is not overcharged
by this extracted power, with voltage boosted, or
depleted beyond safe limits by a system load. In
addition to the highly efficient boosting charger, the
bq25570 integrates a highly efficient, nano- power
buck converter for providing a second power rail to
systems such as wireless sensor networks (WSN)
which have stringent power and operational
demands. All the capabilities of bq25570 are packed
into a small foot-print 20-lead 3.5-mm x 3.5-mm QFN
package (RGR).