OP484
 Op Amp 25A3483-01-KSADW

There were a number of issues that arose with the development of this model. First, it must be stated the worst case PSPICE model was the first approach. However, there were a number of issues that made this approach nearly impossible to do. The PSPICE Model editor was used to create three models using our classical approach of trying to minimize variables for each characteristic down to one or two SPICE parameters. This follows the approach we have used for other parts in the past. However, since you cannot tolerance the PSPICE model directly an attempt was made to map the model characteristics to the individual SPICE elements. This seemed to be a chore but it could be done after much effort. It should be pointed out that Cadence never supplied a Boyle's model for the op amp to use so a similar model was found and used as a template. With this completed asymmetric distributions were developed for some of the SPICE elements. Then Cadence was contacted regarding tolerancing a polynomial source. It was at this point that it was determined that Voltage and Current sources could not be toleranced in PSPICE and even with the use of the Advance PSICE option the tolerances were not supported. It was then decided that a nominal, maximum and minimum model would be used to support multiple Monte Carlo runs.:

  1. The vendor supplied op amp model had a problem with output slew rate.
  2. Asymetrical distributions were needed for some of the SPICE parameters.
  3. Aeroflex developed a Boyle's model because of problems with the MPZ model.
  4. PSPICE does not support tolerancing voltage or current sources.
  5. Needed to switch to Advance PSPICE to use the AWB model templates.
  6. Body problems with Aeroflex Boyle's model.
  7. Output Impedance from Maximum Output Swing Curve not good.

The following is a listing of the PSPICE models developed for the OP484 Op Amp used in the Aeroflex PS Worst Case Analysis. Test circuits were developed to measure the perfromance of the models. A Component Worksheet was also developed to support the WCA effort.
op484_boyle.lib body model
op484boyle.lib body model
op484max.lib body model
op484min.lib body model
op484nom.lib body model
op484wc.lib body model
op484wca.lib body model
op484tst.lib body model

op_amp_test1This simulation circuit was used to check Analog Devices' OP484F op amp model. The OP484F model can be found in C:\Cadence\PSD151\tools\pspice\library\anlg_dev.lib
op484_testThis simulation circuit was used to check Aeroflex's OP484 model. The op amp model is found in the subdirectory parts\op484_boyle.lib. The big question with this model was how the step response changed with capacitive loading. Note the body needs to be fixed as well.
op484f_slew_rate_testThis simulation circuit checks the vendor model, the slew rate of the OP484F. The OP484F model can be found in C:\Cadence\PSD151\tools\pspice\library\anlg_dev.lib
op484max_testThis simulation circuit check the OP484 max model. The max model corresponds to the max parameters listed in the component worksheet. The op amp model is found in the subdirectory parts\op484max.lib.
op484min_testThis simulation circuit check the OP484 min model. The min model corresponds to the min parameters listed in the component worksheet. The op amp model is found in the subdirectory parts\op484min.lib.
op484nom_testThis simulation circuit check the OP484 nom model. The nom model corresponds to the nom parameters listed in the component worksheet. The op amp model is found in the subdirectory parts\op484nom.lib.
op484wc_testMissing stimulus files. Created to test OP484 model using and existing project but stimulus files didn't copy. Can be trashed.
op484wc2_test Created to test OP484 model using and existing project. Body file for op amp is not correct. Can be trashed.
op484wca_testThis simulation circuit was used to check the AWB Model Template version of the OP484. The path to the model checked is parts\op484wca.lib
op484wca_test_offsetMissing stimulus files. Created to test OP484 model using and existing project but stimulus files didn't copy. Can be trashed.
op484wca_test2This simulation was used to troubleshoot the VOS, IB and IBOS problems with the OP484 Model.
test_boyleop484This simulation circuit was used to check Aeroflex's OP484 op amp model. The OP484 model can be found in the subdirectory parts\op484wca.lib
test_op484boyleThis simulation circuit checks Aeroflex's model, the slew rate of the OP484_boyle. The OP484_boyle model can be found in the subdirectory parts\op484_boyle.lib
zout_op484This simulation circuit was used to measure the ouput impedance of the OP484F model supplied by Analog Devices. The OP484F model can be found in C:\Cadence\PSD151\tools\pspice\library\anlg_dev.lib