STGIPL20K60 : Gate and control signals polarity and bootstrap sizing

[axisan]

Hi, i'm using a STGIPL20K60 IPM (SDIP-38L) .

I have a two questions :

• Regarding the control signals :

on ST website produt page regarding which states "Logical Function" : "Negative Input" ; this information is not stated in product's datasheet and not clear enough ?

And in the datasheet gate signals input (HIN and LIN = "NOT LIN") are mentioned, does this mean that wanted LIN signal have to be inverted ?

The truth table states quite the opposite and is contradictory with the waveforms (page 14). (maybe a typo?)

• Rearding bootstrap sizing :

the product's datasheet doesn't cite all the parameters for a correct (exact) bootstrap capacitor sizing (IGBT and driver parameters).

• VF: bootstrap diode forward voltage drop
• VRDS(on): DMOS voltage drop

and :

• QGATE: total MOSFET gate charge
• ILKGS: MOSFET gate source leakage current
• IQBO: bootstrap circuit quiescent
• ILK: bootstrap circuit leakage current
• ILKDiode: bootstrap diode leakage current
• QLS: charge required by the internal level shifters

I'll be glad if anybody could answer these questions or faced similar issues

[MikeDB]

Yes it should say /LIN in the table

[axisan]

Thanks;

[axisan]

@MikeDBThanks; but i'm still struggling with the bootstrap capacitor sizing :

• the STGIPL20K60 doesn't provide Total gate charge of the IGBT used or any precision regarding the characteristics being similar to some other ST product IGBT
• VRDS(on) DMOS voltage drop isn't mentionned.
• ILK: bootstrap circuit leakage current, ILKDiode: bootstrap diode leakage current are not mentionned either but instead an "Undervoltage quiescent current" under Bootstrap section, which isn't defined : does it represent ILK + ILKDiode ?

By making several approximations across different ST products : STGW20H60DF IGBT (for Qgate and VGE(min)) and Vdrop = (Qgate/Tcharge)*RDS(on), the condition which is : Vcbootstrap(min)>=Vbs_threshold isn't fullfiled !

Are there any Ressources such Application Note with real data with the SGTPIL20K60 on ST website ressource section ? Is this a know issue regarding the STGIPL20K60 ?

[MikeDB · Accepted solution]

See section 6.1 in

L638xE application guide - STMicroelectronics

https://www.st.com/resource/en/application_note/cd00004008.pdf

Different IC but principle is still the same

[axisan]

Thanks for you quick answer;

I still can't find any indication about used IGBT's but an approximation should be fine for the bootstrap sizing (which is pretty much sensible to the Gate Charge).

Maybe because i'm a first time user but i find it that the IPM is "poorly" documented and it's time consuming to go through other products datasheets to understand another.

Is there an area where i can report/suggest a revision regarding these ressources ?

Thank You again!!!!

[MikeDB]

IGBTs are still MOS input so the principle is the same. Do the calculations but If your answer is >0.22uF you are probably in the right ballpark. If it's greater than 10uF you've probably got something wrong.

STM's documentation has always been poor so I don't think they are going to listen to any suggestions. We banned using their devices at one of my previous places as we were spending so much time dealing with obsoletion notices and then finding it difficult/impossible to determine if the suggested alternative was good enough or not.