TPS4H000-Q1: output issue

Cooper Zhang1

Part Number: TPS4H000-Q1

Hi,

TPS4H000AQPWPRQ1 is a high-edge electronic switching chip. After the diagnostic enabling pin (P11) is pulled up, when the channel is in the OFF state, but the output voltage of OUT1 is 0.47V, and the output voltage of OUT2, OUT3, and OUT4 is 0V. Please help to confirm whether it is normal

over 3 years ago

0 Shreyas Dmello over 3 years ago

TI__Mastermind 32650 points

Hi Cooper,

Can you share a waveform of the event? What is the load here? Diagnostics Enable does on changes weather faults are reported on the status pin of the device.

Thanks,

Shreyas

0 Cooper Zhang1 over 3 years ago in reply to Shreyas Dmello

Expert 2190 points

Hi Shreyas:

wave as below, it is no load .

0 Shreyas Dmello over 3 years ago in reply to Cooper Zhang1

TI__Mastermind 32650 points

Hi Cooper,

Are the other channels loaded? This seems to be expected behavior caused by the leakage currents for open load detection.

If you were to load this output, we expect the voltage to be pulled to GND.

Thanks,

Shreyas

0 Cooper Zhang1 over 3 years ago in reply to Shreyas Dmello

Expert 2190 points

Hi Shreyas：

others are no load; so it is the normal phenomenon in no load condition ,right ？

0 Cooper Zhang1 over 3 years ago in reply to Cooper Zhang1

Expert 2190 points

Hi Shreyas：

if is，so ，why is only the output1 voltage 0.47V（ the leakage currents ）, others is 0V ?

0 Cooper Zhang1 over 3 years ago in reply to Cooper Zhang1

Expert 2190 points

I found the datasheet shows the pull up resistance is 20KΩ，ctm maybe not put it ，thanks

0 Shreyas Dmello over 3 years ago in reply to Cooper Zhang1

TI__Mastermind 32650 points

Hi Cooper,

To confirm whether this situation is due to the open load, please attach a load to the output and check if the voltage drops to 0V. We expect this open load detection to be present for Version A on Ch1.

If off state open load detection is not required, another workaround is to disable the DIAG_EN pin when the channel is OFF.

Thanks,

Shreyas

0 Cooper Zhang1 over 3 years ago in reply to Shreyas Dmello

Expert 2190 points

Hi Shreyas:

attach a load to the output and check that the voltage can drop to 0V；

but I still have one question , is internal open circuit detection toggled by analog switching? Or is there other problem that causes only channel one to have this leakage current? Could you help me explain that working principle?

0 Shreyas Dmello over 3 years ago in reply to Cooper Zhang1

TI__Mastermind 32650 points

Hi Cooper,

For Version A device, this behavior is expected on Ch1.

Unfortunately, we cannot go into detail on the internal design of the device on a public forum.

Open load detection occurs on this channel when DIAG_EN is high which is the reason behind this leakage current which is used to detect an open load.

Thanks,

Shreyas

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TPS4H000-Q1: output issue