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).