Creating an LTspice Model for the HMC346C8 Voltage Control Attenuator

Issue:

A system designer requires a SPICE model for the HMC346C8 voltage control attenuator to analyze the open loop transfer function of a high power calibrator/amplifier system. The absence of a SPICE model is impeding stability and performance analysis.

Cause:

The HMC346C8 does not have a readily available SPICE model.

Resolution:

To create an LTspice model for the HMC346C8 using available S-parameter files, follow these steps:

1. Download the S-Parameter File:

   • Obtain the appropriate .s2p file for the HMC346C8 from the product page. Multiple .s2p files are available depending on the desired attenuation.

2. Install the s2spice Program:

   • Locate and download the s2spice tool from its repository (referenced as a GitHub project for s2spice).
   • Install the s2spice tool on your operating system.

3. Convert .s2p to SPICE:

   • Launch the s2spice application.
   • Open the desired .s2p file within s2spice.
   • Use the tool to generate the following files:
     • .asy (LTspice symbol file)
     • .inc (LTspice include file)

4. Open in LTspice:

   • Copy or save the generated .asy and .inc files into the LTspice directory.
   • Use these files to incorporate the HMC346C8 model into your LTspice simulations.

By following these steps, you can simulate the HMC346C8 voltage control attenuator in LTspice for system analysis and design.