TAS2110: VBAT Limiter minimum threshold

based on the table above, the UVLO is 2V (min) and the 10.1 power supplies, the boost input is from VBAT 2.9 to 5.5V.

1) is it saying that when the VBAT is lower than 2.9V, the internal boost is not functioning? 

2) as long as the voltage above 2V, the IC is able to function?

Hi,

10.1 is a more system level recommendation. Table 6.3 lists VBAT minimum as 2.7: the minimum VBAT you can have that will maintain performance as documented. When VBAT drops below 2.7, you can no longer rely on it to perform as well as it did with VBAT>2.7V.

It's unknown but the boost is most likely still on even though the performance may degrade due to the lower voltage. The part will remain on until you reach VBAT <= 2V which triggers shutdown. That region 2V<VBAT<2.7V is an unknown that we don't recommend operating in.

Best regards
Jeff McPherson

Hi

we would like know what is the consequences if the IC operate at 2V<VBAT<2.7V? 

Hi,

I'll test this and get back to you by the middle of next week.

Thank you,

Jeff McPherson

Hi,

I tested an EVM with VBAT 2V<VBAT<2.7V. I didn't observe any noticeable drop in performance until 2V where the Under Voltage triggered and shut the device down. I still can't guarantee that all features will behave well across devices when VBAT <2.7V but I hope that gives you knowledge to move forward.

Best regards,

Jeff McPherson

Hi jeff,

thank you for the reply.

During the test with VBAT 2V<VBAT<2.7V,  the Internal boost(class G) still working?

Hi,

No, the Internal Boost shuts down at about 3V due to the charge pump no longer being able to support it. In this range you will be pretty limited in your output volume because there is no boost. However the output appears to continue to work without performance degradation.

hi,

since the internal boost shutdown at about 3V. So during high output, the THD performance will be different between 2.9V and 3.1V(with boost). is that correct?

hi,

since the internal boost shutdown at about 3V. So during high output, the THD performance will be different between 2.9V and 3.1V(with boost). is that correct?

Hi,

Yes, without the boost, high output will cause clipping and impact THD performance negatively. I had to turn down my input volume during the test to prevent clipping after the boost shut off.