TPS65235: The function of R,C which are parallel with inductor

Ben Kuo

Expert 7570 points

Part Number: TPS65235

Dear expert,

Our customer would like to learn from you what the function of RC which parallel with boost inductor(220uH)?

How to calculate this RC value? Can we change to 220nF with 220uH inductor?

Thanks!

Ben

over 7 years ago

0 Jason Wang (BSR-MV) over 7 years ago

TI__Genius 9550 points

Hi Ben,
I am looking into your request and will give you answer on Monday.

0 Sam(MPAA) Zhang over 7 years ago

TI__Mastermind 19080 points

Hi Ben,

Do you mean the 220uH inductor in red circle?

It acts as a RLC filter. In DiSEqC 2.x protocol, it's a 2-way communication between LNB and the switch box. The LNB can work in both receiver and accessory mode. When it works as a receiver, the parallel FET is ON and tone signal goes to switch box. When it works as an accessory, the FET is OFF and the signals from switch box is filtered out, so the output of LNB is not affected.

For the detail, please refer to the application note below, (Chapter 3.2.2)

Regards,

Sam

0 Sam(MPAA) Zhang over 7 years ago

TI__Mastermind 19080 points

So please don't change the value of the RLC.

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TPS65235: The function of R,C which are parallel with inductor