TINA-TI: Convergence problem. Cehck the analysis parameters

Adam Daluga

Part Number: TINA-TI
Other Parts Discussed in Thread: TIDA-01040, OPA827, INA128

Hello,

I am trying to do transient analysis with TINA-TI and keep getting the error "Convergence problem. Check the analysis parameters!"

What can I do to solve this?

Thanks,
Adam

over 2 years ago

0 JMac over 2 years ago

TI__Intellectual 1955 points

Hi Adam,

This often happens when there are issues with one or more of the SPICE models in a circuit, or things fail to converge due to instability. Can you upload a copy of the TINA design you are trying to simulate?

Cheers,

Jon

0 kai klaas69 over 2 years ago

Guru 140200 points

Hi Adam,

please post your simulation file.

Kai

0 Adam Daluga over 2 years ago in reply to kai klaas69

TI__Expert 5680 points

Hi all,

Thanks for the help. Please see the file attached.

tidm034 (1).zip

Best,
Adam

0 JMac over 2 years ago in reply to Adam Daluga

TI__Intellectual 1955 points

Hi Adam,

It looks like you're trying to simulate the TIDA-01040 reference design. The transient sim does not appear to be modified from the original version (here). The sim seems to be locking up because something in the OPA827 model is unhappy. I ran the unaltered transient sim that is included with the other TIDA-01040 simulations and saw the same error occur.

I was able to fix it by including a 10.5 ohm resistor between the output/feedback of the OPA827 and the 1.5k resistor. This resistor appears in the schematics on the reference design page but is missing from the sim. Once the resistor was added, the simulation did converge, although it took some time to do so. After getting it to run with the 10.5 ohm resistor I added the 10pF cap and it again converged.

I'm not very familiar with the OPA827 or its model, so perhaps someone from the high-speed group can weigh in with more details as to exactly why this occurs.

Cheers,

Jon

0 kai klaas69 over 2 years ago in reply to Adam Daluga

Guru 140200 points

Hi Adam,

it's the usual mistake: TINA-TI does not like too many OPAmps running in one simulation. So, as you know what the output signal of INA128 will be, divide and conquer: