PTH08T210W: Triming the output voltage

Meng Chan74

Part Number: PTH08T210W

Hi, What is the best way to trim the output voltage(1.0V) by +/-5% ? Can the Vo_adj accept voltage source override, with what drive strength?

Thanks,

Meng

over 5 years ago

0 Denislav Petkov over 5 years ago

TI__Mastermind 19070 points

Hello Meng,

Using the Vo_adj may be one option. Let me check with the team what the internal schematic looks like.

Cheers,
Denislav

0 Denislav Petkov over 5 years ago in reply to Denislav Petkov

TI__Mastermind 19070 points

Hello Meng,

Here are the details on the internal (on the module) feedback resistors:

You can use ADJ terminal to adjust the output voltage. You could switch in different R values or use a DAC to inject current into the ADJ pin to shift Vout.

Cheers,
Denislav

0 Meng Chan74 over 5 years ago in reply to Denislav Petkov

Prodigy 50 points

Hello Denislav,

Thank you very much. It seems it would be easier to switch the Rset value to trim the Vo.

Meng

0 Meng Chan74 over 5 years ago in reply to Denislav Petkov

Prodigy 50 points

Hi Denislav,

I thought about the switching Rset method for trimming the Vo. I can see that there will be discontiunity (break-before-make) during the Rset swithing. Would you know how sensitivty the Vo to the Rset switching discontiunity if trimming the Vo from 1.0V (63.7k) to 0.97V (Rset=71.5K), and then 0.95V (77.79k)?

Thanks

Meng

0 Denislav Petkov over 5 years ago in reply to Meng Chan74

TI__Mastermind 19070 points

Hi Meng,

I think it would be good to always have a resistor connected for one Vout value and achieve the trimming by switching in parallel combinations. That way you won't risk having an open circuit on the pin and Vout defaulting to Vref.

For example, you could have a default resistor always installed for the lowest voltage (0.95V) and switch in large resistors in parallel so that you get a parallel combinations resulting in 0.97V and 1V out.
If the switches are open, then you will get a default of 0.95V always.

Let me know if this makes sense.

Cheers,
Denislav

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PTH08T210W: Triming the output voltage