TPSF12C3: Line frequency range

Vijay Jaswa

Prodigy 10 points

Part Number: TPSF12C3

Will the TPSF12C3 AEF IC work at 400 Hz line frequency for aerospace applications?

1 month ago

0 Ben C 1 month ago

TI__Mastermind 29235 points

Hi Vijay,

With sensing capacitors (CSEN1-4) of 680pFand TPSF12C3 internal components, the combination creates a high-pass filter that attenuates 50Hz/60Hz line frequency by ~100dB. At 400Hz of line frequency, the rejection is less and the IC will see around 50 times more of the 400Hz signal than the standard 50Hz/60Hz signal. The IC will work at 400Hz of line frequency but there may be some line frequency signal appearing on the output of the INJ pin.

Ben

0 Vijay Jaswa 1 month ago in reply to Ben C

Prodigy 10 points

Thanks, Ben, that clarifies things. However, even if some line frequency signal appears on the output of the INJ pin at 400 Hz, it should manifest as a differential mode noise signal, and that should not matter if I am trying to get rid of common mode. Is that correct? Should I simply reduce the Csns caps, and try with an eval board, or will the scheme just not work?

+1 Ben C 1 month ago in reply to Vijay Jaswa

TI__Mastermind 29235 points

Hi Vijay,

The IC rejects DM noise and only focuses on CM noise. The 680pF sense caps creates an optimal high-pass filter response that rejects 50Hz/60Hz signals and would not recommend other values. You can order a single-phase EVM filter board to evaluate its performance.

Ben

0 Vijay Jaswa 1 month ago in reply to Ben C

Prodigy 10 points

Thanks

0 Ben C 1 month ago in reply to Vijay Jaswa

TI__Mastermind 29235 points

Hi Vijay,

No problem. Glad to be of help! :-)

Ben

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TPSF12C3: Line frequency range