Digital Libraries for ngspice

[tomhajjar]

Issue #900 was getting too long...

@ra3xdh since you are assigning this task to a student I though this info might help.

ngspice supports multiple Digital Libraries but the ones one from "MicroCap" offer the most devices. These are simple models that support gate delays and I/O voltage levels. More complete models can be found but there are so few the Library would be tiny.

MicroCap_dig000.lib has 74, AC, LS, HC...etc. Unfortunately there are many missing devices.
MicroCap_74lv.lib has a wide selection of 74LV devices.
MicroCap_cmos.lib has CD4000 devices.
MicroCap_ecl.lib has ECL devices.

There may be other MicroCap Digital Libraries. They would need to be tested to work in ngspice.

I have created four projects containing 74HC and 74LV devices.

Digital_HC_prj to create and test sub-circuits for Digital_HC.lib
Digital_HC_lib_prj to test the library Digital_HC.lib

Digital_LV_prj to create and test sub-circuits for Digital_LV.lib
Digital_LV_lib_prj to test the library Digital_LV.lib

I created Digital_HC.lib and Digital_LV.lib. They need to be expanded with more devices.

symbols_logic.sch contains some useful symbols.

The Libraries contain device descriptions and analysis requirements for use.

One can convert devices from one family to another. You would need to alter all the delays, capacitances and voltages.

Digital_device_projects.zip

[tomhajjar]

I found additional MicroCap Digital Libraries. The following are included above.

dig000.lib
74lv.lib
cmos.lib
ecl.lib

MicroCap_digital_libs.zip

[tomhajjar]

Found a NXP 74HC component-level library. Might be useful for mixed-signal analysis, I used the 74HCU04.
https://assets.nexperia.com/documents/spice-model/hc.zip
https://forum.allaboutcircuits.com/threads/74hcu04.185257/

To make individual Spice models requires a lot of copy-paste. A device might have 6 sub-circuits throughout the files.

NXP 74HC_component-level.zip

[ra3xdh]

Found a NXP 74HC component-level library.

Thanks! This would be the best library for analog mode simulations.

[tomhajjar]

LTspice uses sub-circuits called dviewX making calls to dview.lib to create Timing Diagrams. This is another option.

LTspice Digital-View.zip

[tomhajjar]

@ra3xdh

Any digital libraries from your students you want me to review? Always best to catch issues early. ;-)

[ra3xdh]

There is no progress on this subject yet.