TPS74901: About simulation of TPS74901 TINA-TI Transient Reference Design (slim257.tsc)

Masanori Tachibana

Part Number: TPS74901
Other Parts Discussed in Thread: TINA-TI

Hello support team,

I ran a transient analysis simulation of TPS74901.
I used "slim257.tsc" which is downloaded from "TINA-TI Transient Reference Design" on your homepage of TPS74901.

As a result of simulation, the output voltage seems to be a little lower than expected.
I investigated the cause, and found that simulation result of VREF is 0.786 V although it is 0.802 V (TYP) and 0.798 V (MIN) on the datasheet.

Why is VREF voltage less in the simulation result?
Is the simulation model strange?
Could you teach me?

Sincerely,
M. Tachibana

over 4 years ago

0 Stephen Ziel over 4 years ago

TI__Mastermind 29400 points

Hello Masanori,

I will review this model and get back to you after I get into the office tomorrow.

It may take up to 2 business days for a reply, but I will take a look.

Thanks,

- Stephen

0 Masanori Tachibana over 4 years ago in reply to Stephen Ziel

Genius 5350 points

Hello Stephen-san,

Thank you for your prompt reply.
I look forward to your advice.

Best regards,
M. Tachibana

0 Stephen Ziel over 4 years ago in reply to Masanori Tachibana

TI__Mastermind 29400 points

Hi Masanori,

I reviewed the netlist of the TPS74901 spice model.
The designer of the model used 0.8V to model the reference voltage.
If you open the netlist file, in the .PARAM statement the parameter Vref=0.8.

I downloaded the Cadence PSpice model and created the same circuit in Cadence Orcad, but I received the same results.
It seems the error is somewhere else inside the model.

It appears that this is a deficiency of the model, and you will need to account for this small error going forward in your DC analysis.

Thanks,

- Stephen

0 Masanori Tachibana over 4 years ago in reply to Stephen Ziel

Genius 5350 points

Hello Stephen-san,

Thank you for valuable information.

I understood that there is something error in this model although the reference voltage should be modeled at 0.8V.
For DC analysis, I understood that it is necessary to consider this error.
Does this small error affect the results of transient analysis?

Best regards,
M. Tachibana

0 Stephen Ziel over 4 years ago in reply to Masanori Tachibana

TI__Mastermind 29400 points

Hi Masanori,

The accuracy of the transient analysis will be relatively unaffected by this discrepancy in output voltage.

Thanks,

- Stephen

0 Masanori Tachibana over 4 years ago in reply to Stephen Ziel

Genius 5350 points

Hello Stephen-san,

Thank you for your prompt reply.
I understood.
And I appreciate your kind response.

Best regards,
M. Tachibana

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TPS74901: About simulation of TPS74901 TINA-TI Transient Reference Design (slim257.tsc)