TPS43061: TPS43061 datasheet DCR sensing

lev nemets1

Part Number: TPS43061

Hello,

Datasheet for this controller gives an example of typical application (page 21). Note on this page says that for DCR sensing ,open R14 and short R15, R16, R17. But in this case inductor will be directly connected to sense input of controller. The voltage across inductor is rectangular shape pulse (need saw shape pulse for current loop)with amplitude equel Vin , and this is much higher current limit threshod. Could you, please , explane how this circuit can work.

Thanks

over 5 years ago

0 Yinsong Cai1 over 5 years ago

TI__Expert 7450 points

Hi lev,

The voltage feeds into the chip is the voltage across the cap, which is in series with a resistor. It is not the rectangular voltage across the inductor but a RC-filtered voltage.

This is the popular DCR sensing method. You can google search 'DCR current sensing' and you can easily find the equations and required relationship of the RC network.

Thanks,
Yinsong

0 Yinsong Cai1 over 5 years ago

TI__Expert 7450 points

Hi lev,

Please let me know if you have further concerns. I'm still looking for the amplifier gain and slope comp info you asked for.

Thanks for considering TPS43061.

0 lev nemets1 over 5 years ago in reply to Yinsong Cai1

Intellectual 475 points

Hi Yinson,

Thank you for reply. I know this method. But there is no such capacitor on circuit diagramin datasheet (page 21) and, if you follow recomendation in the notes on this page, you will connect inductor directly to sense inputs of controller.

I think that such a reputable company as TI should fix this inaccurate in datasheet and SLVU799A.

Thaks

Lev

0 Yinsong Cai1 over 5 years ago in reply to lev nemets1

TI__Expert 7450 points

Hi Lev,

I believe it is C12.

Thanks,
Yinsong

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TPS43061: TPS43061 datasheet DCR sensing