TAS5755M: TAS5755M output DC voltage between OUT_P and OUT_N

Hi

I can not open your schematic, can you check the file and upload it again?

Best regards.

Wei Qiu.

Hi Wei,

thank you,pls try it again.

3480.TAS5755M数字功放板_A1_Schematic.pdf

Hi wei,pls see below picture.

yellow chanel shows current of spk,and purple chanel shows PWM signal,if the current up to very  high,the PWM signal disappear for a few milliseconds.

Hi

I still can't open the pdf file...

According to your waveform, I think this maybe caused by Over-Current Protection, under BTL mode the protection point is 6A, and under PBTL mode will be double, 12A.

If the device is triggered the OCP will result in the power stage being set in the high-impedance (Hi-Z) state, which will cause the PWM signal disappear. And the device returns to normal operation once the fault condition (that is, a short circuit on the output) is removed. 

Maybe you can change a bigger Load or use PBTL mode to have a try.

Best Regards.

Wei Qiu.

HI，Wei，

what's your email address?I will sent The schematic to your Email.

the case use 2pcs 5755M,1 for BTL and other one for PBTL,the problem only happen to PBTL.We have changed a 6 ohm load SPK,output power set to 32W,test result is OK.

becase the spk is  MP material,  very hard to change impedande,is there any other way to limit the current?like DRC or other setting?

Hi

My e-mail is wei-qiu@ti.com.

I don't think there exist some good methods to limit the current because the OCP point is fixed. I think you can decrease the gain of your AMP to avoid this condition.

Best Regards.

Wei Qiu.

We also found that the error register 0X02 show all errors,whatever in normally working or in abnormally.

Moreover,the overcurrent error can result in a DC voltage between OUTA&B and OUTC&D?

Hi

Do you mean the register 0x02 value is fe? Rather than 02?

And can you post the waveforms of the differential voltage of the output?

Best regards.

Wei Qiu.

The problem occurs only in PBTL, the value of 0x02 is 40 (no audio is played)，then starts accumulating to FC when music is played.  the error output state also show OUTA&B=13.28、OUTC&D=10.89.below picture show the moment of error happened.