TPSF12C3: how Observation indicators in simulation(common current?or other)

PIM LI

Part Number: TPSF12C3
Other Parts Discussed in Thread: TPSF12C1

The following is normal condition(IC work) simulation result,and observe common current at input side(common current=IR+IS+IT)

I TRY TO SWITCH IC VDD 0V=off IC,(so this IC should be off ，no work，no injection current)

and simulation result as follow

there is no injection current,but why this case common current same to IC work?

over 1 year ago

0 Jimmy Hua over 1 year ago

TI__Guru 50120 points

Hello,

I've looped in the appropriate apps engineer to help look into your question.

Regards,

Jimmy

0 Timothy Hegarty over 1 year ago in reply to Jimmy Hua

TI__Guru 74812 points

Hi Pim,

Tie EN pin low to disable the IC. This keeps the INJ pin low, so the inject cap can still behave as a Y cap.

Please use the TPSF12C1/3 quickstart calculator, particularly for stability, and refer to the EVM user's guides for the AEF design flow. I attached the latest quickstart file here for convenience:

1581.TPSF12C3 quickstart calculator A5.xlsm

Also, here is a convenient resource hub for AEF that includes FAQs:

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1257197/faq-tpsf12c1-and-tpsf12c3-power-supply-filter-ic-faqs

Regards,

Tim

0 PIM LI over 1 year ago in reply to Timothy Hegarty

Prodigy 10 points

thanks reply

more question ：in simulation,In addition to Cinj current, where can we observe that the IC work

0 Timothy Hegarty over 1 year ago in reply to PIM LI

TI__Guru 74812 points

Hi Pim,

You can probe the INJ pin voltage to see the IC operating.

Regards,

Tim

0 PIM LI over 1 year ago in reply to Timothy Hegarty

Prodigy 10 points

I MEAN THE FILTER CIRCUIT PERFORMANCE

IF I USE IC,HOW EFFECT TO FILTER(COMMON CURRENT SMALLER?OR OTHER)

0 Timothy Hegarty over 1 year ago in reply to PIM LI

TI__Guru 74812 points

Hi Pim,

You can enable and disable the IC to check the performance difference when making an EMI measurement. Note that AEF here only applies to common-mode (CM) noise, so check that the differential mode (DM) noise is not too high - otherwise the DM will dominate and you may not see the improvement in CM when measuring the total noise. Another option is to use a DM-CM plitter so you can look at CM noise separately.

Regards,

Tim

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TPSF12C3: how Observation indicators in simulation(common current?or other)