TINA and LTspice IV

David,

After checking the performance of the circuit, we have found two things that have added to the difference in the TINA simulation. The first was the missing 50 ohm resistor at the input. The second issue was more difficult to find. Apparently, a couple of parameters in TINA's built in transistor model were different from the current manufacturer's model. I am attaching a new TINA_reset_changed .TSC file to this post for your to evaluate. The parameters changed were the Reverse Beta (from 5 to 1.3) and the Reverse transit time (from 51.7n to 5.17n).

After these changes are made, the waveforms look more closely similar. As with any test between two simulators, there will be differences due to the individual nature of each simulator (defaults, convergence alogrithms, tolerances, numerics, etc.).

Please let us know if you have any additional questions.

Britt Brooks

4188.TINA_reset_changed.TSC