TPS2493: TPS2493PWR

Thomas Lochmatter1

Part Number: TPS2493

Hello

We are using the TPS2493PWR. During tests I observed the following behaviour. If the device switches off because of an overcurrent event occured, it tries to restart in time Intervals with gaps of TRETRY as described in the datasheet. How many times does it do that? I observed different number of retry cycles: e.g 13 times, 28 times, 41 times.. After that, the device shut down and could be restarted by eliminating the overcurrent source and performing a power cycle.

Best regards

Thomas

over 4 years ago

0 Praveen GD over 4 years ago

TI__Guru 57737 points

Hi Thomas,

Welcome to e2e!

I am looping in Rakesh to help you on this query. Meanwhile, can you share your schematics.

0 Rakesh over 4 years ago in reply to Praveen GD

TI__Guru* 95911 points

Hi Thomas,

Retry time is fixed and should follow the behavior described in Page-19 of the datasheet. Can you please share few test waveforms along with the schematics.

BR, Rakesh

0 Thomas Lochmatter1 over 4 years ago in reply to Rakesh

Prodigy 60 points

Below you can find the schematics:

If I measure the VOUT (TP2003) in case of load is connected which consumes more than 12.45A, the voltage @ TP2003 switches on and off every 0.996s. The voltages rises up to env 5V for env 20ms. After different number of such cycles, the device operation stops.

0 Rakesh over 4 years ago in reply to Thomas Lochmatter1

TI__Guru* 95911 points

Hi Thomas,

Thank you!

As asked, Can you help with couple of test waveform during retry mode of operation. Share the details of the test condition.

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

Any update on the test waveforms to look into the issue.

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

Please feel free to reopen the thread as soon as you get test waveforms.

BR, Rakesh

0 Thomas Lochmatter1 over 4 years ago in reply to Rakesh

Prodigy 60 points

Hi Rakesh

Measurement #1: pin 11, OUT. After an overcurrent event occurs, the voltage switches off and the TPS2493 tries to restart env. every 1s. -> behaviour as expected.

After a certain time (not always same), the device stops working.

The following pic shows the OUT pin (yellow) and the TIMER pin (blue) during restart trials:

At the points where the cursors are, is a voltage spikes on channel 1.

The following pic shows the OUT (yellow) and the TIMER (blue) pin at the time, where the device stops working:

The following pic shows the OUT (yellow) and the PROG (blue) pin during a restart trial:

Thomas

0 Rakesh over 4 years ago in reply to Thomas Lochmatter1

TI__Guru* 95911 points

Hi Thomas,

Thanks for the test waveforms.

Can you check by removing R2010 (3.9k) resistor. I just want to disable UVLO, OVP and then see to rule out any dependencies.

Also, is the device still functional or failed ?

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

Is the device still functional or failed ?

Is similar retry behavior (of different number of retry cycles) observed across multiple devices ?

Can you reach out to TI local sales to submit the units for failure analysis.

BR, Rakesh

0 Thomas Lochmatter1 over 4 years ago in reply to Rakesh

Prodigy 60 points

Hi Rakesh

It seems that the device is working. I made the following test on another board. I removed the resistor R2010 (3k9), triggered an over-current event by connecting a big load and then the device retries to start during 9 hours... Then I stopped this test, placed R2010 again, triggered an over-current event and had the same behaviour as last time with the other board. Means, after a certain time (< 1h), the device stopped working (no start retries visible). Then I removed R2010 again, triggered a over-current event and could see start retries for more than 3 hours. Then I stopped the test. For me the behaviour depends on the presence of R2010. You mentioned something about undervoltage. Could you explain a little bit more in detail what do you exactly mean?

BR Thomas

0 Rakesh over 4 years ago in reply to Thomas Lochmatter1

TI__Guru* 95911 points

Hi Thomas,

I just want you try by disabling UVLO. There is no relation to UVLO to the behavior you observed. Also, we never seen this kind of issue.

Let me know the operating test conditions, how you loaded the unit so that I can cross verify at my end.

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

Can you share test conditions. ?

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

Any update ?

BR, Rakesh

0 Thomas Lochmatter1 over 4 years ago in reply to Rakesh

Prodigy 60 points

Hi Rakesh

I connected the Input to 24V (two lead acid batteries in Serie) and at TP2003 a Culatti power resistor with a variable resitance value. Then I decrease the resistance until the TPS2493 Switches off the MOSFET.

0 Rakesh over 4 years ago in reply to Thomas Lochmatter1

TI__Guru* 95911 points

Hi Thomas,

I will test at my end and get back by 10th Oct.

BR, Rakesh

0 Rakesh over 4 years ago in reply to Rakesh

TI__Guru* 95911 points

Hi Thomas,

I have not seen any such shutdown issue at my end. Can you please ship a board to me for debug ?

BR, Rakesh

0 Thomas Lochmatter1 over 4 years ago in reply to Rakesh

Prodigy 60 points

Hi Rakesh

Unfortunately, we have not enough boards for send you one of them.

0 Rakesh over 4 years ago in reply to Thomas Lochmatter1

TI__Guru* 95911 points

Hi Thomas,

OK understood. Let me know if there is any other way to help.

BR, Rakesh

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TPS2493: TPS2493PWR