This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS54232EVM-415: Using Higher Input Voltage

Part Number: TPS54232EVM-415
Other Parts Discussed in Thread: TPS54232, TPS54233EVM-373, TPS54233

Hi team,

We are interested in using the TPS54232 in an application to buck 18V down to 15V for a 1A load.

Looking at the EVM for this part, it says the input voltage range is only up to 15V even though the part is rated for 28V. Will there be an issue with using this EVM for 18Vin? Do I need to make any modifications to make it work for this? It looks like I will have to change R6 to 575 Ohm according to Formula 1 in the EVM User's Guide.

Also, are there any other/better parts that we should be looking at for this application? 


Akash Patel

  • The input capacitor is rated for 25 V, at 18 V input, it will have less effective capacitance.  You may want to add a second capacitor on the unused C2 pads.  C3 is only rated for 10 V.  You will definitely need to change it for 15 V output. As you note you will need to change one feedback resistor to change the output voltage.  The output inductor and compensation network are also designed for this specific application.  They may work as is, but you should check them following the datasheet design guide.  The catch diode is only rated for 20 V.  I would recommend a 30 V part to have some margin.  The resistor divider for EN sets the external UVLO for the device.  It is probably set for around 4.5 V.  You will want it set to somewhere just above 15 V.  So basically, you will need to change just about everything, but TPS54232 should allow you to meet your 18 V to 15 V design.

  • Hi John,

    Seems like I have a good amount of work in front of me in order to get this working for this application.

    It looks like the TPS54233EVM-373 will take 18Vin, but to output 15V, I imagine I will have to make some changes there too. It looks like the output capacitor, C9, is not listed in the BoM (there is a C8 on the BoM but not on the schematic as well). Do you know what the rating is for this capacitor?

    Akash Patel
  • Looks like a typo in the BOM.  C9 in the schematic is 470 uF, it is C8 in the BOM and is rated for 10 V.  Either TPS54232 or TPS54233 EVM will take a lot of modification, especially if you want to optimize for your Vin and Vout..  I think it is your choice on which best suits your needs.