STPTIC tunable capacitor DC Ground

[KTrot.1]

Hi.

I have the STPTIC-82G2 tunable capacitor, and I have noticed that there is no ground pin. What is the DC ground that the bias pin is referenced to? Should I provide DC ground through RF1/RF2 pins?

Thank you!

[JPROO.1]

Hello,

There is No GND pin, for Bias pin reference you should provide DC ground return through RF1 or RF2

No matter which one as they are DC connected internally in the PTIC

Best Regards

jean-pierre.proot@st.com

[KTrot.1]

Thanks for the answer!

Does that mean that RF1 and RF2 are DC shorted? What happens if they are DC biased with different voltages? Should I avoid it?

[JPROO.1]

RF1 and RF2 are not DC shorted, you have to connect RF1 or RF2 to DC ground thru a shunt inductor for instance.

If you bias RF1 or RF2 to a DC voltage (reference) then this reference will be substracted from the Vbias (Vbias - reference)

Hope it answers you question

[KTrot.1]

If, for example, RF1 is biased at 5V DC, and RF2 is biased at 3V DC, what will the be reference voltage to the "bias" pin?

[JPROO.1]

Please see internal schematic

if RFin and RFout are not using the same DC voltage there will be leakage current

[JPROO.1 · Accepted solution]

[KTrot.1]

Thanks a lot!