TINA/Spice/LM5116: Convergence Issue with TINA-TI LM5116 Transient Model

Pranesh Kulkarni50

Part Number: LM5116
Other Parts Discussed in Thread: TINA-TI, , LM5118

Tool/software: TINA-TI or Spice Models

I am using LM5116 to Simulate in TINA-TI. I have used updated Spice Model from this forum. Even with new model, the output voltage is not reaching the desired output (output is 12V @ 3Amp). Currently, I have removed the load and verified, the result is same, Vo is not stuck as low as 200mV. Please help me to solve the issue. Our simulation has stuck here, and further processing has become an issue.

over 7 years ago

0 David Baba over 7 years ago

TI__Mastermind 39940 points

Hello Pranesh,

I have notified an individual, who should respond shortly. Thanks.

David.

0 Saket over 7 years ago

TI__Intellectual 2680 points

Hi Pranesh,

Could you please share your TINA schematic with us?

Regards,
Saket

0 Pranesh Kulkarni50 over 7 years ago in reply to Saket

Prodigy 180 points

Dear Saket,

Please find the attached TINA-TI schematics. Help to solve the issue.LM5116_Test.TSC

0 Saket over 7 years ago in reply to Pranesh Kulkarni50

TI__Intellectual 2680 points

Hi Pranesh,

I do not see any convergence issue (with attached tsc file) in latest version of TINA 9.3.150.328 SF-TI.(Please refer below image)

Could you please confirm which version of TINA you are using?

Below is the simulation result with attached tsc file

VBridge or VIN is 4.42V which is not enough to generate 12V output. I am not sure if bridge rectifier is giving desired output.

Another thing I observed that output capacitors were missing at VOUT node in schematic.

I added them in schematic and simulated the test bench with 48V DC voltage. Model regulates at 12V VOUT with 3A load current. PFA tsc file and below are the simulation results.LM5116_Test_DC.TSC

Please let me know if you have any queries on this.

Regards,

Saket

0 Pranesh Kulkarni50 over 7 years ago in reply to Saket

Prodigy 180 points

Dear Saket,

Thanks a lot for your reply. TINA version used is same as yours. Convergence error is solved now. As you suggested Vout_Bridge output is not reaching beyond 4V. I have run the simulations for 500m and found Vout_Bridge reaches more than 15V. With this the LM5116 output is not reaching 12V. However, with DC input (without Bridge), It reaches 12V and proper load.
Please suggest.

0 Saket over 7 years ago in reply to Pranesh Kulkarni50

TI__Intellectual 2680 points

Hi Pranesh,

I am replicating the same issue in TINA and will try to get back on this within couple of days.
Thank you for your patience!

Regards,
Saket

0 Pranesh Kulkarni50 over 7 years ago in reply to Saket

Prodigy 180 points

Dear Saket,

Waiting for your reply.

0 Saket over 7 years ago in reply to Pranesh Kulkarni50

TI__Intellectual 2680 points

Hi Pranesh,

The issue was with resistor divider present at UVLO pin. I changed the ratio and device is getting enabled for ~15V. Below is the change done in schematic and simulation result.

Old Resistor divider

New Resistor divider

Simulation Result

Please note that CLOAD of Bridge rectifier is decreased to 100u from 10m in order to see settle transients quickly.

Kindly let me know if you have any queries.

Regards,

Saket

0 Pranesh Kulkarni50 over 7 years ago in reply to Saket

Prodigy 180 points

Dear Saket,

Thanks a lot for your reply. It was nice to see my problems getting solved. There is change in requirement, we need to use buck-boost converter for our final product. So we are moving ahead to use LM5118 in our module.

Thanks a lot for your reply.

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TINA/Spice/LM5116: Convergence Issue with TINA-TI LM5116 Transient Model