Cd4051 Spice Model Link ((free))

Finding a dedicated SPICE model for the analog multiplexer can be challenging because it is a legacy CMOS part. Many manufacturers do not provide standalone SPICE models for these older logic ICs directly on their product pages. TI E2E support forums Available Models and Alternatives LTspice Community Models

While Analog Devices does not manufacture the CD4051, the community and ADI utility libraries often include generic CMOS multiplexers or specific CD4051 models. cd4051 spice model link

Depending on your simulation environment, you can obtain the necessary .lib or .sub files from these reputable sources: Finding a dedicated SPICE model for the analog

Because the CD4051 is essentially a set of eight voltage-controlled switches and a 3-to-8 decoder, many SPICE veterans don't use a link at all. They use a generic cd4051 spice model link