SLUAAR2 august   2023 BQ27Z746

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Reverse Charger Protection with Optional RCP Circuit
  6. 3Reverse Charge Protection Without Optional RCP Circuit
  7. 4Summary
  8. 5References

Abstract

This application note introduces design option for RCP (Reverse Charge Protection) feature that is offered with the BQ27Z746. The RCP feature will be required by cell manufacturers to prohibit reverse charging of battery packs in the system and make sure safety. Most BMS (Battery Management System) IC requires a parallel FET to implement RCP feature. However, this can be a design limitation for some applications with limited PCB sizes such as smart phones and wearables. The BQ27Z746 Impedance Track™ battery gauge design is a highly integrated, accurate 1-series cell gas gauge and protection design with integrated RCP feature. Using a parallel FET for RCP is no longer required if BQ27Z746 is used in the system and it can be determined by system needs. Therefore it can help save PCB size and BOM cost. This document describes how RCP feature can be implemented without parallel FET and with it for both cases.