TPS51623: VCORE current sensing design

chentsu chung

Part Number: TPS51623

Hi,

Based on the Excel calculation, here's some question:

1. where's the I_TDC in intel's spec?

For example, the power VNN in spec, our customer can only find the maximum current is 3.5A, and the I_TDC does affect the result of DCR pass or fail.

Or how do you recommend to decide the I_TDC based on the maximum current?

2. Can I set I_TDC lower if I can keep the heat away?

3. In the datasheet of TPS51623, there are 2 way to sense current-inductor DCR sensing or resistor current sensing.

Is there any reference circuit and calculation about resistor current sensing?

4. If end-product has size limitation, so can't chose low DCR inductor. Is it ok to use resistor current sensing?

Thank you.

over 7 years ago

0 Rama Pamidi over 7 years ago

TI__Intellectual 1790 points

Hi Chung,

1. I_TDC will not effecr DCR pass or fail. I_TDC is defined by INTEL, so please check with INTEL.
2. No. I_TDC is defined by INTEL.
3.i don't think, we have seperate excel for resistor current sensing.
Resistor current sensing case caluculations are easy. No-need to add DCR thermal compensation. update Rcs_eff = Rsense (in excel) or you can send me excel and Rsense value, i will update and send back to you.
4. yes. you can choose resistor current sensing.

Thanks.
Regards,
Rama.

0 chentsu chung over 7 years ago in reply to Rama Pamidi

Mastermind 6180 points

Hi Rama,

1. But for a fixed DCR value, the E63 value (pass or not) of excel file will also change if I modify I_TDC.

If I modify I_TDC value lower, then the result will be "pass" even if DCR is bigger.

2. If now we try to use resistor current sensing, is the modified circuit correct? the schematic correct?

0 Rama Pamidi over 7 years ago in reply to chentsu chung

TI__Intellectual 1790 points

Hi Chung,
1.that DCR fail related to thermal. please click on E63 (IF(DCR_Ploss<DCR_Pmax,"PASS","FAIL, DCR too high")). so don't worry for lower currents.
2. that is correct.

Thnaks.
Regards,
Rama.

0 chentsu chung over 7 years ago in reply to Rama Pamidi

Mastermind 6180 points

Hi Rama,

Thank you very much!

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TPS51623: VCORE current sensing design