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TPA3245: Connecting a speaker in PBTL mode after the LC filter

Part Number: TPA3245
Other Parts Discussed in Thread: TPA3255


I'm trying to switch between BTL stereo and PBTL mono mode without making any circuit changes other than M1,M2 pins and pulling down INC and IND.

Would it be safe to connect the speaker as PBTL after the filtering capacitors?

TI datasheet application sample

What I'm trying to do

  • Hi,

    It's OK, but please note that this configuration actually made the output capacitance doubled. May I ask why you are thinking about doing so? Is it the limited AC power capability of the capacitor?




  • Hi Sam!

    Thanks for the fast response. I am testing the TPA3255 EVM for both BTL stereo and PBTL mono mode, but I only have 1 EVM board. Removing and soldering the OUTC/OUTD shunts got really tired, so I wanted to check if it was safe to test the PBTL mode even with the shunts not removed from the board.

    I will try to change the output capacitor values so that the high frequencies are not as filtered in the PBTL mode

    Best regards


  • Hi Brian,

    Understood. Just short the SpkA and SpkC together for PBTL setting(similar to SpkB and D). 1uF to 2uF doesn't has much impact. Just remember the LC frequency response is changed a little bit.