Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide Mixed analog/digital simulation October 2019 642 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. the same as the level 2 DtoA interface, except that the level 2 DtoA interface does not generate intermediate R, F, and X levels. The OrCAD libraries provide two different DtoA models in the HC/HCT series: the simple model and the elaborate model. You can use the simple model by specifying level 1 or 2, the elaborate model by specifying level 3 or 4. The elaborate model is noticeably slower than the simple model, so you should only use it if you are using a power supply level other than 5.0 volts. The HC/HCT level 1 and 2 DtoA models produce accurate I-V curves given a fixed power supply of 5.0 volts and a temperature of 25°C. The level 3 and 4 DtoA models produce accurate I-V curves over the acceptable range of power supply voltages (2-6 volts), and they include temperature derating. Level 1 interface The level 1 AtoD interface generates intermediate logic levels (R, F, X) between the voltage ranges VILMAX and VIHMIN (specific voltages depend on the technology you are using). A steadily rising voltage on the input of the AtoD will transition from 0 to R at VILMAX and from R to 1 at VIHMIN. The F level is output for steadily falling voltages in a similar manner. The X level is produced if the input voltage starts in the threshold region or doubles back into a previously crossed threshold. Level 1 (the default) strictly maps logic levels onto the changing input voltage. The exact switching voltage is assumed to be anywhere Table 15-1 Interface subcircuit models Level Subcircuits Definition 1 AtoD1/DtoA1 AtoD generates intermediate R, F, and X levels 2 AtoD2/DtoA2 AtoD does not generate intermediate R, F, and X levels 3 AtoD3/DtoA3 (same as level 1) 4 AtoD4/DtoA4 (same as level 2)