TAS5720A-Q1: Abnormal waveform of SLEEP pin when turing power off

Hi Sam,

We will take a look and then provide our feedback.

Andy

Sam,

Seems it is reasonable that the SPK_SLEEP will drop , because the VDD should also droped at the same time.



Dylan

Hi Dylan,

Can you explain more details? My expectaion is that SPK_SLEEP should remain LOW when turning off the power. But, the SPK_SLEEP first goes to high and then drop. I need the root cause for my customer.

Thanks,
Sam Lee

Sam,

The SPK_SLEEP is a input pin, so the voltage level depends on customer DSP/Uc.  i think customer followed datasheet guidance, put SPK_SLEEP to high before set SPK_SD to low.  so the detailed steps would be:

1. DSP/Uc detected PVDD lower than a threshold

2. set SPK_SLEEP to high.

3. set SPK_SD to low, then PWM stop.

4. PVDD continue drop, and VDD also drop.

5. SPK_SLEEP high level drops with VDD.

Hi Dylan,

Thank you for your exlanation for sequence. I'll give you more question by email.

Thanks,
Sam Lee