TPS40210: Switching Frequency

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS40210

Hi,

Switching frequency depends on VDD on customer's circuit.

It is 86kHz at VDD=12V, it is 84kHz at VDD=30V.

Is this variation valid?

The RC pin is connected with VDD via a resistor on the schematic.

RT and CT connected with RC pin are 680kΩ and 220pF

Best Regards,

Kuramochi

over 5 years ago

0 Youhao Xi over 5 years ago

TI__Guru 74230 points

Hi Kuramochi-san

No, it is virtually not vary with input voltage. The frequency is basically determined by the time constant of the R and C. Please refer to the datasheet Sectoin 7.3.5.

Best Regards,

Youhao Xi, Applications Engineering

0 Kuramochi Tadahiko over 5 years ago in reply to Youhao Xi

Guru 28715 points

Xi-san,

Thank you for your support.

Though we observe frequency variation actually, what do you consider as this cause?

Best Regards,

Kuramochi

0 Youhao Xi over 5 years ago in reply to Kuramochi Tadahiko

TI__Guru 74230 points

Hi Kuramochi-san,

There will be some variations owing to the nonlinearty of the internal oscillator circuit. The datasheet actually also gives out the variation limits vs line in the EC table. Sorry I forgot to tell in previous reply: the variation that you observed seems normal.

Best Regards,

Youhao

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TPS40210: Switching Frequency