SDAA050 August   2025 BQ25180 , BQ25186 , BQ25188 , BQ25622E , BQ25638 , BQ25798 , BQ25890 , TPS2121

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Possible Architectures
    1. 2.1 Power Mux
      1. 2.1.1 Other Power Mux Considerations
      2. 2.1.2 Power Mux Over Voltage and Priority Settings
      3. 2.1.3 Power Mux Testing
    2. 2.2 Multicell Charger IC
    3. 2.3 Dual Chargers
    4. 2.4 eFuses (USB OTG)
  6. 3Summary
  7. 4References

1 Introduction

There are several circuit topologies that can be used to design a dual input battery charger system. This application note methodically explores the use of a power mux in combination with a single cell battery charger IC. The document also discusses a number of other possible designs including two parallel chargers, a multicell charger with dual input functionality, and the use of eFuses.

The power mux design is likely the most simple to implement and is preferred for a variety of applications, however each of the following designs has a place in certain applications. The advantages and disadvantages of each architecture are discussed thoroughly including a comparison of the prices for a particular example of each design presented.