If you need help setting up your simulation schematic, let me know:

The small current flowing when the switch is off.

This error occurs if LTspice cannot find the model file or if the naming conventions do not match. Ensure that the .include statement points to the correct directory path and that the component's Value attribute exactly matches the name following the .subckt text inside the library file. Convergence Errors During Transient Analysis

Texas Instruments provides robust SPICE models for their CD4000 series. Look for the "CD4051B PSpice Model" or "CMOS Behavioral Models" library on the official TI website under the CD4051B product page. These files are fully compatible with PSpice and LTspice.

Below are the verified sources for functional CD4051 SPICE models.

: If you cannot find a "CD" specific model, look for HEF4051 (NXP) or MC14051 (ON Semi) models, which function identically for most simulations. 2. How to Import the Model

Finding models for older CMOS ICs (4000 series) can be tough, as they are not always provided by modern manufacturers like TI. Here are the best sources: The Best Choice: LTspice Community Model

(positive supply). If you are only switching positive analog signals, you must explicitly connect VEEcap V sub cap E cap E end-sub VSScap V sub cap S cap S end-sub

For a deeper understanding of how these types of ICs are modeled at a "deep paper" level, you can refer to:

: For variants like the MC14051B (a direct CD4051 equivalent), Onsemi hosts SPICE models directly on the component product page under "Design Resources." Understanding the CD4051 SPICE Subcircuit

is the primary source. While they don't always provide a standalone