TAS3251: TAS3251 Issue

Hi Ian,

Question :
1. What’s the happen condition for three behavior? how much temp it over ? how much voltage it lower ? how much current it higher ?
a. CLIP_OTW pin goes low
JB: This means the part is in over temp warning, the junction temperature is above 125C. The part will shut down at 150C.
b. CLIP_OTW pin toggles
JB: This is pre clip warning, or clipping. Meaning the device will toggle CLIP_OTW before clipping happens (output voltage is near PVDD limit) or when the output is already clipping.
c. FAULT goes low
JB: The device has shut down the outputs.

2. I found U4 is easier than others occur CLIP problem , have you ever did experiment for single output then C17/C18 installed , and it’s stable and without any issue like thermal cause clipping?
JB: We do not recommend operating the device without BST caps on the all 4 outputs. I believe the best case for this part is to put it into pre-filter PBTL. This would require directly grounding the INC and IND inputs, and setting the mode pin to 1. This will give you the benefit of not spending cost on another LC set for CD outputs, and should keep the device in normal operation. You will also get the benefit of a reduced Rdson on the output FETs, and therefore a bit better thermal performance.

3. Since there is no output on BST_C & OUT_C , so I would like to ask if I remove C17/C18/R200/R201 , do you have any concern for this configuration ? any side effect ?
JB: If you are going to continue using the device with just the BAST caps on the output you should AC couple the INC and IND pins to ground with a capacitor. If you are not already, you should be muting the Right output of the DAC.

Justin