Difference between revisions of "220-A2.1"
| Line 3: | Line 3: | ||
* At the end of this activity, the student should be able to: | * At the end of this activity, the student should be able to: | ||
# Understand and observe the effects of the fabrication process on passive RC circuits. | # Understand and observe the effects of the fabrication process on passive RC circuits. | ||
| + | |||
| + | == Reading Assignment == | ||
| + | Go over the Phillip Allen's excellent slides on [https://aicdesign.org/wp-content/uploads/2018/08/lecture07-140310.pdf resistors and inductors] and [https://aicdesign.org/wp-content/uploads/2018/08/lecture06-140818.pdf capacitors]. Focus on the non-idealities of integrated resistors and capacitors, and how designers can work around these non-idealities to create reliable circuits. | ||
== Modeling Integrated RC Circuits == | == Modeling Integrated RC Circuits == | ||
| − | + | In order to model and simulate integrated resistors and capacitors, we can create semiconductor resistor models in SPICE that contains the sheet resistance of the layer, and the temperature coefficient. Consider an n-type polysilicon resistor, with <math>R_\mathrm{sh} =100\mathrm{\Omega}</math>, and <math>T_C =-800\mathrm{ppm/^\circ C}</math> at a nominal temperature, <math>T_\mathrm{nom} =27\mathrm{^\circ C}</math>. Let us create a resistor model '''rpoly_n''': | |
| + | |||
| + | <source lang="bash"> | ||
| + | .model rpoly_n R rsh=100 tc1=-800u tnom=27C | ||
| + | </source> | ||
| + | |||
| + | Instantiating a resistor using the '''rpoly_n''' model, with the appropriate width and length, as: | ||
| + | |||
| + | <source lang="bash"> | ||
| + | R1 in out rpoly_n w=2u l=20u | ||
| + | </source> | ||
| + | |||
| + | We can also create a capacitor models using: | ||
| + | |||
| + | <source lang="bash"> | ||
| + | .model cmom C cj=50m tc1=30u tnom=27C | ||
| + | </source> | ||
| + | |||
| + | Where '''cmom''' is the model name of the capacitor, '''cj''' is the | ||
| + | |||
| + | |||
== Effects of Process Variations == | == Effects of Process Variations == | ||
Revision as of 07:33, 22 September 2020
Activity: Integrated Resistors and Capacitors
- Instructions: This activity is structured as a tutorial with a design problem at the end. Should you have any questions, clarifications, or issues, please contact your instructor as soon as possible.
- At the end of this activity, the student should be able to:
- Understand and observe the effects of the fabrication process on passive RC circuits.
Reading Assignment
Go over the Phillip Allen's excellent slides on resistors and inductors and capacitors. Focus on the non-idealities of integrated resistors and capacitors, and how designers can work around these non-idealities to create reliable circuits.
Modeling Integrated RC Circuits
In order to model and simulate integrated resistors and capacitors, we can create semiconductor resistor models in SPICE that contains the sheet resistance of the layer, and the temperature coefficient. Consider an n-type polysilicon resistor, with , and at a nominal temperature, . Let us create a resistor model rpoly_n:
.model rpoly_n R rsh=100 tc1=-800u tnom=27C
Instantiating a resistor using the rpoly_n model, with the appropriate width and length, as:
R1 in out rpoly_n w=2u l=20u
We can also create a capacitor models using:
.model cmom C cj=50m tc1=30u tnom=27C
Where cmom is the model name of the capacitor, cj is the
