TAS6424E-Q1: About automatically retrying DC diagnostics

miyuki.fukumoto

Part Number: TAS6424E-Q1

Hello everyone,

We are planning to use the function that automatically repeats DC diag in our product.
This is based on the method described in sloa286's application report.

Page9
>If the DC diagnostics are triggered automatically before entering MUTE or PLAY mode, the device will keep retrying without a control command being needed if any fault is detected.

When I monitored the waveform, it appeared to be repeating at a 1000ms cycle.

I would like to know how much this cycle time changes depending on the parts (or surrounding circuit design).

Are there any detailed explanations or application notes about the features?

Thanks,Miyuki

9 months ago

0 Gregg Scott 9 months ago

TI__Mastermind 37565 points

Fukumoto-san,

The 1000ms cycle is based on an internal timer. No external circuitry will influence the time. There are no application notes to detail this timer.

Regards,
Gregg Scott

0 miyuki.fukumoto 9 months ago in reply to Gregg Scott

Prodigy 60 points

Hello Mr.Scott,

Thank you for your reply!

Please tell me When does the internal timer start counting 1000ms?

Does the count start after setting the error report for each channel?
Or does the count start after DC diag on all channels is completed?

With best regards,

Fukumoto

0 Gregg Scott 9 months ago in reply to miyuki.fukumoto

TI__Mastermind 37565 points

Fukumoto-san,

What are you trying to do? There may be a better solution than using timers.

Regards,
Gregg Scott

0 miyuki.fukumoto 9 months ago in reply to Gregg Scott

Prodigy 60 points

Mr.Scott,

We would like to implement a retry mechanism for DC diagnostics.
The application report(sloa286) describes a method to count N times, but considering MCU control, I thought it would be better to have AMP-IC execute the retry and then have the MCU time out after a while.

Checking the waveform, it appeared that execution continued even if the 0x04 register setting was changed to Hi-Z during the DC diag retry.
Since it is undesirable for there to be a gap between SW and HW movements, we want to set the optimal timeout timing.

I asked this question to consider the optimal timeout timing.

Regards,
Fukumoto

0 Gregg Scott 9 months ago in reply to miyuki.fukumoto

TI__Mastermind 37565 points

Fukomoto-san,

The state of the output can be checked by reading register 0x0F. You could easily read this after a certain amount of time and if it is still in the Load Diagnostic state, you can time out the amp and abort the Load Diagnostics and keep the bad channel in Hi-Z and log the load diagnostic fault.

Regards,
Gregg Scott

0 miyuki.fukumoto 9 months ago in reply to Gregg Scott

Prodigy 60 points

Mr.Scott,

Thank you for your kind reply.
After trying out your proposal, there are two things I would like to know.

I've attached an image so please check it out.

Regards,
Fukumoto

+1 Gregg Scott 9 months ago in reply to miyuki.fukumoto

TI__Mastermind 37565 points

Fukomoto,

In register 0x09 bit 7, you will need to abort the automatic load diagnostics to make them stop. After it is aborted, you can then make the channel Hi-Z.

Regards,
Gregg Scott

0 miyuki.fukumoto 9 months ago in reply to Gregg Scott

Prodigy 60 points

Mr.Scott

I see, I guess a command to cancel was necessary.
Thank you for answering my question.

Regards,
Fukumoto

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TAS6424E-Q1: About automatically retrying DC diagnostics