LM25116: The lower MOS transistor (synchronous rectifying) of the PSPICE model is continuously off.

Jos Achten

Part Number: LM25116

Running the test transient simulation in the PSPICE for TI environment does not show the lower MOS transistor switching. It is continuously off. There exists no synchronous rectifying. I tried also in a heavy load situation. Is the model wrong? I used the transient model. The upper transistor is switching. I downloaded the test circuit directly from the TI webpage.

over 1 year ago

0 David Baba over 1 year ago

TI__Mastermind 40040 points

Hello Jos,

Can you please share the model you are using?

Thanks.

David.

0 Jos Achten over 1 year ago

Prodigy 10 points

Hi David,

The model comes directly from the webpage of TI. Go to https://www.ti.com/product/LM25116#design-development and then select the second from top (LM25116 PSpice Transient Model). It includes a complete demo circuit. Here the transient model of the IC is encrypted.

With Siemens / Mentor I checked it too but now with the unencrypted transient model (4th from the top - LM25116 Unencrypted PSpice Transient Model) and build the same circuit as in the demo around the model. It gave the same results.

Maybe there is a MOS transistor inside the model pulling down the SW node when the (external IC) MOS transistor X2 should be activated.

With regards,

Jos

0 David Baba over 1 year ago in reply to Jos Achten

TI__Mastermind 40040 points

Hello Jos,

I ran the start up stimulation and there does appear to be an issue with this, I will feed this back and have this fixed in due course, in the meantime, please feel free to use WEBENCH if needed.

Thanks.

David.

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LM25116: The lower MOS transistor (synchronous rectifying) of the PSPICE model is continuously off.