TPA2005D1-Q1 Short to GND protection

Hello,

The appropriate applications engineer has been notified of your question, and will respond soon.

Regards,
Karl

Hello Clancy-san,

Thank you for your answer.

Please answer following additional questions for TPA2005D1-Q1 form customer.

Q1:

Please let me known how to work short to GND protection.

 -Does protection monitoring the current of Vo- and Vo+?

   If yes, please let me known typical value of current limit.

 -Please advise the behavior after detect short.

   For example, all 4 FET of H-Bridge is OFF and short is latched or device will re-start after xx delay.

 

Q2:

Please answer if short to GND is detected for following each condition.

 -/Shutdown terminal is Low.

 -Speaker is driven by audio signal

 -Input is 0V and speaker is not driven.

 

Q3:

Please advise the state of H-Bridge FET when /Shutdown terminal is Low.

Are all FET OFF?

 

Q4:

Please advise if TPS2005D1-Q1 has short to battery protection.

 

Best Regards.

Toshio,

Q1 and Q3:  If an over-current condition is detected on the outputs, the output FETs will be turned off.  Note that when the power supply is lower, the current might not be enough to trip the over-current protection, and instead it will enter thermal shutdown.  From tests done before, we know that the short circuit protection will work at 5.5V, but that at 3.6V, it will enter thermal shutdown before the overcurrent condition is tripped.

Q4: The TPA2005D1-Q1 does not have short to battery protection. 

I need to do some lab work to answer your other questions, which I will do next week.

Thanks,

-Clancy

Hello Clancy-san,

Thank you for your answer.

 

Q1:

I want to confirm my understanding of action when I use VDD=5V and short to GND is happen.

According to your answer, do you say that occurrence of over-current detection or thermal shutdown is not determined?

 

Also, please advise how to restart after over-current is detected and FETs are turned off.

 

Q2:

Please answer Q2.

 

Best Regards.

Hello Clancy-san,
I have meeting with customer this Friday morning (Japan time) about TPA2005D1-Q1.
So, could you please answer my question until this Thursday (US time)?
Best Regards.

Toshio,

I had to order another EVM, which just arrived, so I'll be able to do the testing and get back to you tomorrow.

Thanks,

-Clancy

Hello Clancy-san,

Thank you for your cooperation.

I hope your answer tomorrow.

Best Regards.

When VDD = 5V, and a short to GND occurs, the device will detect the short and turn off the output FETs.  After testing this on the bench, the device stays in shutdown until either the SHUTDOWN pin is toggled low and then high again, or power is cycled.

Q2:

The device will detect the short circuit condition while it is in the normal operating state.  This is true whether or not it is driving a speaker and regardless of what the audio input signal is.

If the device is in shutdown mode, the outputs are not active so it will not detect a short circuit condition.  If the short circuit condition is removed before exiting shutdown, then the device will work properly.  If the short circuit is maintained, then it will be detected as soon as the device attemps to exit the shutdown state.

 

Hello Clancy-san,

Thank you very much for your answer.

I could answer to customer's question and they will use TPA2005D1.

Could you kindly answer additional following question?

 

Please advicse what will happen if Vo+ and Vo- short to Battery (9V to 14V).

For example, device may be damaged but it will not be extraordinary heated or burned.

 

Best Regards.

Above the maximum voltage (6V normal, 7V in shutdown), the device could be damaged.  They will need external protection circuitry if their system needs to survive that condition.

Thanks,

-Clancy

Hello Clancy-san,

Thank you for your answer.
Customer knows that TPA2005D1 could be damaged when Vo+ and Vo- shorts to Battery (9V to 14V).
They want to know the amount of damage, for example, device will be damaged but it will not be extraordinary heated or burned, or could be heated and/or burned.

Best Regards.