I am using TAS5613A power amplifier to drive audio signal (3.5KHz to 4KHz) in PBTL mode. The Load resistance will be around 9-10Ohm. I have constructed the schematics as given in the datasheet, what i noticed is the Output (out A, B, C, D) doesn't have the filter capacitor.
Does it require a filter capacitor in series with the Load and output, if not why we don't need?
Does the load gets damaged if we are not using a series capacitor?
Please review this Design Note which I believe addresses your concerns.
Audio Applications Engineering Manager
Dallas, TX USA
Hello Don Dapkus,
Thanks for your reply on my earlier post.
We have the output noise issue (Hiss) and the input current is High in Ideal mode, I have constructed the schematics as in Demo board (OPA 1632+TAS5613A). I am applying 35V to the bridge of Power amplifier. The 35V supply current is around 120mA, But in datasheet its around43mA(12V+Half bridge current) when in Ideal. I have configured the power amplifier to PBTL (BD mode).
I am giving the input to A and B (C is connected to VREG and D is connected to GND). What we observed is Hiss noise at the output (connected Speaker with 9-10Ohm load). Speaker has a frequency response till 16KHz.
I connecting the preamplifier input to GND for verification, when both input are grounded we won't hear any HISS but when any one input is grounded then we will hear the HISS at the output (And when input is open also we hear HISS).
I have attached the Schematics of preamplifier and Power amplifier schematics.
We are unable to open the file, "Power Amplifier.pdf"
It generates an error on our computers.
Can you re-generate it and re-post it?
Hi Don Dapkus,
Please find Attached power amplifier PDF.
Please find attached Power amplifier PDF.
Great! Thank you.
Jade will get back with you shortly on this issue.
Hi, Sreekanth,I checked your schematic. Also, I want to check your layout, too.Could you post your layout?Thank you.Regards,Jade
How are you jade?
Hope schematics is fine.
I cannot post Layout as it is confidential.
If you can give your mail Id then i can send it to you.
Sorry for the delay. One of the guys is looking at your question.
Mr Jade goo requested for PCB layout and i have sent them already But not received any comments or suggestion from him.
looking forward for solution.
I am using TAS5613A for one of our product, I have constructed the schematics as in Demo board (OPA 1632+TAS5613A). I am applying 35V to the bridge of Power amplifier. The 35V supply current is around 120mA, But in datasheet its around43mA when no input is applied. I have configured the power amplifier to PBTL (BD mode).
I am giving the input to A and B (C is connected to VREG and D is connected to GND). What we observed is there is Hiss noise at the output (Speaker with 9-10Ohm load).
I tried connecting the preamplifier input to GND for verification, when both input are grounded the we won't hear any HISS but when any one input is grounded then we will hear the HISS at the output (And when input is open also we hear HISS).
I checked your schematic and layout.
Thank you for your review on our PCB layout.
I am are using a square heatsink for power amplifier so the DC blocking capacitors are bit far from the input of power amplifier.
What i observed is when no input is connected to the pre amplifier we wont hear any noise, but if i ground any one input of pre amplifier we start hearing noise at the output.
i tried grounding both the input of pre amplifier but the result is same.
i don't know what is the reason for that.
Looking forward for your earliest reply.
I will measure the output integrated noise and let you know the same.
Thanks & regards,
I have not received any update from your side waiting for your reply.
Could it be that your ground is noisy and injecting noise into the amp?
Did you get a chance to measure the noise floor? And FFT might be useful, too.
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