PSPICE-FOR-TI: Making schottky diode with PSPICE Modelling Application

Attila Varhelyi

Part Number: PSPICE-FOR-TI
Other Parts Discussed in Thread: TPS61165

As I see, only power diode could be choiced in PSPICE Modelling Application.

This diode type does not allow to setup Vf below of 0.4V for SMPS simulation under the wizard. However I can modify its property on the sheet as workaround, but I get very false simulation results after this. It seems very unusable.

Unfortunately, the TI's reference designs (e.g. TPS61165) use type of DD diode, which is ideal and it has Vf=8mV!

Could you tell me more about constraints and usability of this power diode type?

Is there any alternate way to define schottky diode and avoid importing external compenent and degrade PSpice for TI into very restriction mode?

Attila

over 5 years ago

0 JC Zhu over 5 years ago

TI__Mastermind 37790 points

Hi Attila,

I am consulting the designer of this model and will get back to you this week.

Thanks,
JC

0 Lawrence Arledge over 5 years ago in reply to JC Zhu

TI__Prodigy 70 points

Hello, Attila:

From your email:

> This diode type does not allow to setup Vf below of 0.4V for SMPS simulation under the wizard. However I can modify its property on the sheet as workaround, but I get very false simulation results after this. It seems very unusable.

We will work on your request. Would you send us a test case? Also, please explain your requirements for the diode.

Thank you.

Best regards,

Lawrence

0 Attila Varhelyi over 5 years ago in reply to Lawrence Arledge

Intellectual 615 points

Hi Lawrence,

I would like to simulate differrent SEPIC SMPS's with coupled inductors. But there we are runnning other SMPS topologies like BOOST/BUCK with TPS61165.

I would like to determine the exact efficiency, power dissipation and step-in DCM mode points at different loading, and under VIN with using real components.

The target diode type is PMEG4005EJ or similar.

Other components and details in nutshell about SEPIC SMPS is here:

(7) PMP10835: How can I make a coupled inductor in "PSpice for TI" from two uncoupled inductor? - Simulation, hardware & system design tools forum - Simulation, hardware & system design tools - TI E2E support forums

PS: At this moment ticket above is in open state, so I am waiting for TI's response, how can I use coupled inductor models for correct simulation.

Attila

0 Lawrence Arledge over 5 years ago in reply to Attila Varhelyi

TI__Prodigy 70 points

Hello Attila,

I have been able to import and simulate a Schottky diode, as you requested. It took much longer than expected to do this, since, during debugging, I found my version of Pspice for TI and model libraries were buggy. So, I updated as follows:

1. Allegro/Pspice, 17.4.-2020-S004

2. Re-install the TI Models and Libraries using “Help > Reinstall TI Models and Libraries”

3. Refresh the caches

Regarding your earlier question on the "power diode" model, it does not have all the parameters explicit in the model form that one needs to easily construct a Schottky diode. The Schottky diode has a lower barrier height and possibly smaller N factor in the exponent. I’ve included the NXP PMEG4005EJ diode (as you suggested) and can send you the zip file.

Please let me know if this works for you.

Thank you and best regards,

Lawrence

PS: Please accept my friend invitation, and I will send the zip file. Thank you.

0 Lawrence Arledge over 5 years ago in reply to Lawrence Arledge

TI__Prodigy 70 points

Hi Attila,

Thank you. I received your email letting me know you received the zip file containing the working Schottky diode circuit.

Please let us know if this works.

Thank you for your collaboration.

Best regards,

Lawrence