TPSM82866A: tdelay

Mia Ma

Part Number: TPSM82866A

Hi team,

Could you please help with following question?

there is a description ''The tDelay time varies with the VSET/MODE resistor used and is longest with a resistance of 249 k or higher''

And there is a table as following:

so I am little confusing here, for example, I am wanting a 0.90V output, I should choose a 18.7k resistor at Vset/mode pin.

Q1. Will my tdelay to be a matched delay time, right?

Q2. if Q1 answer is 'Yes', so there will be only one delay time under one output voltage condition, this delay is not actually adjustable?

Q3. How about, if Vset pin is 0.90V, the Vset/mode logic is low, so the part must worked under a PSM?

Thanks

Best regards

Mia Ma

over 3 years ago

0 Chris Glaser over 3 years ago

TI__Guru**** 150750 points

Hi Mia,

The device automatically adjusts the tdelay time based on the resistor value. Here is a more detailed explanation of the R2D converter: https://www.ti.com/lit/wp/slyy180/slyy180.pdf

The delay time is fixed internally inside the IC. It cannot be adjusted, except by changing the resistor value (before startup).

Yes, if you use a resistor on the VSET/MODE pin, then the pin will be pulled down by the resistor. You can achieve a high level on the pin after startup by applying a logic high voltage. See this app note: https://www.ti.com/lit/an/slvaf64/slvaf64.pdf

Thanks,

Chris

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TPSM82866A: tdelay