TPS543C20: Overvoltage protection Level

JH Shin

Mastermind 7840 points

Part Number: TPS543C20

Hello,

My customer encountered an issue which the level of the overvoltage protection was not constant.

When VREF is 0.6V, they consider that the level of the OVP is max 1.05V VOUT according to the table below.

If VOUT = 1.05V, then about 0.729 will be input to the RSP pin.

However, OVP works when the actual VOUT is 1.1V to 1.13V.

Please advise on the cause of this symptom.

Thank you.

over 2 years ago

0 Tahar Allag over 2 years ago

TI__Mastermind 29440 points

Hello JH,

The device compare the RSP pin voltage to internal selectable pre-set voltages. If I understand you setting, you selected 0.6V as VREF using VSEL res=0. Then you set the VOUT using a resistor divider on SRP. In this case, the OVP will be 113% to 121% (min and max) (typical=117%) of your target preset VOUT.

1the OVP on 0.6VREF will be anything between 0.678V to 0.726V. You just need to scale that up to your RSP target value to find the OVP on the RSP pin.

Thanks!

Tahar

0 JH Shin over 2 years ago in reply to Tahar Allag

Mastermind 7840 points

Hello Tahar,

Thanks for your reply.

The customer will check if the OVP works at 0.678V ~ 0.726V with RSP pin input voltage.

They has additonal question.

Could you please tell us all the conditions that could cause the TPS543C20's power good alarm?

Regards,

0 Tahar Allag over 2 years ago in reply to JH Shin

TI__Mastermind 29440 points

Hi JH,

If the output voltage goes outside of ±12% of the target value, the power good signal becomes low after an internal delay.

thanks

Tahar

0 JH Shin over 2 years ago in reply to Tahar Allag

Mastermind 7840 points

Hi Tahar,

What happens to the PG signal if the TPS543C20's internal thermal shutdown is caused by overtemperature protection?

Thank you.

0 Tahar Allag over 2 years ago in reply to JH Shin

TI__Mastermind 29440 points

Hi JH,

In Thermal shut down, power conversion stops, output voltage goes outside of ±12% of the target value, the power good signal becomes low.

Thanks

Tahar

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TPS543C20: Overvoltage protection Level