Unregulated power supply pulse charger using DS2770

DS2770 is a battery fuel gauge and lithium-based and nickel-based chemical battery charger control integrated chip produced by Dallas Semiconductor. It can communicate with the power management system through the Dallasl-Wire interface to read battery voltage, temperature and other detection information, and read and write E2PROM at the same time, so it can be widely used in portable electronic devices. The unregulated power supply pulse charger based on DS2770 is shown in the figure below.

The DS2770 battery monitor and charge controller provides comprehensive battery maintenance functions. Each DS2770 has a unique 64-bit ID, a digital temperature sensor, an analog-to-digital (A/D) converter for measuring battery voltage and current, an integrated current accumulator (for recording the total amount of current flowing into and out of the battery), an elapsed time recorder, nonvolatile memory for storing important parameters, and an integrated charge controller that supports rechargeable lithium and NiMH batteries.

The DS2770 sends and receives information via the 1-Wire interface, so only one wire (and ground) is needed between the processor and the DS2770. This can greatly save CPU hardware resources. When working in conjunction with the main system's processor, the DS2770 inside the battery pack can perform functions such as charging, remaining capacity estimation, safety monitoring, and non-volatile (NV) parameter storage.