TPS1663: how large Cdv/dt cap is acceptable

Takashi Onawa

Part Number: TPS1663

Hi Team,

My customer wants to use this device with 20 parallel connections, and they want to choose a long SS to minimize the inrush current of the system to be as small as possible. So could you tell me how large Cdv/dt cap can be acceptable for TPS1663?

Regards,

Takashi Onawa

over 5 years ago

0 Rakesh over 5 years ago

TI__Guru** 105361 points

Hi Takashi,

Thanks for reaching out!

There is no limit on the Cdv/dt cap value for the eFuse devices. You can use large Cdv/dt cap to set lower inrush currents. An example is discussed in the app note http://www.ti.com/lit/an/slva920/slva920.pdf

Best Regards, Rakesh

0 Takashi Onawa over 5 years ago in reply to Rakesh

TI__Genius 13200 points

Hi Rakesh-san,

Thanks for your prompt response on this. I understood TPS1663 also can deal with large Cout cap from the material.

Sorry, What I wanted to know is how small current can be used as limited inrush current...
TPS1663 needs to be waked up within 1.25s, so I can understood this might introduce some limitation but are there other any restrictions?

here is one study case. It's nice if you can tell me settable min Iinrush in this case.
Vin 24V
Cout 200uF

Regards,

Takashi Onawa

0 Rakesh over 5 years ago in reply to Takashi Onawa

TI__Guru** 105361 points

Hi Takashi,

The inrush current to the Cout is Iout = Cout *Vin/t_startup = 200uF *24V/1.25s = 3.84 mA.

As the device operates in open loop during inrush current control, I do not expect any issue or limitations. However, I suggest you to evaluate other use cases in your system.

Why such low inrush current needs to be limited in your system ?

Best Regards, Rakesh

0 Rakesh over 5 years ago in reply to Rakesh

TI__Guru** 105361 points

Hi Takashi,

Did you get to know "Why such low inrush current is needed" for the customer ?

Best Regards, Rakesh

0 Takashi Onawa over 5 years ago in reply to Rakesh

TI__Genius 13200 points

Hi Rakesh-san,

Let's talk about the detail on off line.

I will send you a email later.

Regards,

Takashi Onawa

0 Takashi Onawa over 5 years ago in reply to Takashi Onawa

TI__Genius 13200 points

Hi Rakesh-san,

Could you tell me your email address?

Regards,

Takashi Onawa

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TPS1663: how large Cdv/dt cap is acceptable