I've been trying to perform a basic transient analysis within LTSpice using the ADG408 multiplexer, and have been getting very strange results:
- The output voltage spikes when the address is changed, but the corresponding switch input is not transferred.
- A substantial amount of current is sometimes drawn at the switch inputs.
- Changing the enable input seems to have no effect.
I've tried a variety of configurations, and have been unable to get the model to work as expected. Is this a limitation of the model or LTSpice, or am I doing something incorrectly?
I've attached the LTSpice schematic and symbol I created, along with a screenshot showing the unexpected behavior. The A2:A0 pins are driven with 3.3V pulse sources configured to produce a 3-bit binary count pattern.
The ADG409 Spice model produces similar results.