TPS543C20A: Switching frequency accuracy

Han Wang

Part Number: TPS543C20A

Hi team,

May I ask about the max and min value of the switching frequency set by the resistor? We are seeing a 45kHz error on the fs.

Thanks,

Han

8 months ago

0 Britton Jones 8 months ago

TI__Expert 6596 points

Hi Han,

What FSW setting are you selecting? There is some tolerance to the setting and to the resistor. That said, the fsw settings are not discrete so you can adjust the resistor slightly to achieve your desired setting.

Best regards,

Britton

0 Cai Lin 8 months ago

Prodigy 30 points

Hi Britton,

In addition to the error caused by the external resistor, in the range of -40C to 125C, how much error is brought by the internal chip?

BR//

Songlin

0 Britton Jones 8 months ago in reply to Cai Lin

TI__Expert 6596 points

Hi Songlin,

It can be up to +/-10%

Best regards,

Britton

0 Cai Lin 8 months ago in reply to Britton Jones

Prodigy 30 points

Hi Britton，

We found that under heavy and light load, the switching frequency has a change of 2kHz, is this normal? Could you explain the reason? My understanding is that they work in fixed frequency mode instead of COT mode.

BR//

Songlin Cai

0 Cai Lin 8 months ago in reply to Cai Lin

Prodigy 30 points

Hi Britton，

In addition, could you please provide normal distribution data of switching frequency tolerance (+/-10%)?

BR//

Songlin Cai

0 Britton Jones 8 months ago in reply to Cai Lin

TI__Expert 6596 points

Hi Cai,

Are you seeing the frequency shift down by 2kHz at high loads? This is likely due to higher IC temperature and is not unexpected. I do not have distribution data that I can share externally

Best regards,
Britton

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TPS543C20A: Switching frequency accuracy