SNVAA30 December   2021 LM5170-Q1

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Commercial Vehicle Power System
    2. 1.2 Operation of Battery Equalizer
  3. 2Designing Buck Converter with LM5170-Q1
    1. 2.1 VHV to VLV Buck Converter with 13-A Maximum Output Current
    2. 2.2 Inner Current Loop Design
    3. 2.3 Outer Voltage Loop Design
    4. 2.4 Implementation of Current Limit
  4. 3Experimental verification
  5. 4Conclusion
  6. 5References

2.1 VHV to VLV Buck Converter with 13-A Maximum Output Current

GUID-20211201-SS0I-DS0V-XB28-ZP48R8CVCZ1S-low.gif Figure 2-1 Schematic of Buck Converter for Battery Equalizer

Figure 2-1 shows schematic of the buck converter with LM5170-Q1. VHV is the input voltage connected to the 24 V port, which is also the 24-V rail, VLV and is the output voltage connected to the 12-V port, which is also the 12-V rail. Synchronous buck converter is implemented with QH1 and QL2 MOSFET while LM5170-Q1 channel-2 is disabled. RCS1 is the shunt resistor to sense inductor current of buck converter. The current sense signal is used for inner current loop regulation. The output voltage of the equalizer is regulated by an external Op-amp LM6142. The designs of the inner current loop and external voltage loop to achieve constant current operation and voltage equalization are detailed in the following section.