Every software package contains a full set of examples suitable for that version and are installed with the software. If you see examples here that are not in your installation you should consider updating to a later version of the software. These examples can be used by beginners and advanced users for product evaluation, teaching purposes, and self-training.
Required Modules
Victory Process:
- 2D Core Simulator
Victory Mesh:
- 2D Meshing
Victory Device:
- 2D Simulator
- 2D TFT
- 2D MixedMode
The purpose of example explains how to make an equivalent TFT pixel circuit in Victory Device/Mixedmode simulation software. This aims at demonstrating how to set up TFT pixel equivalent circuit including passive element such as resistance and capacitance arising from pixel and liquid crystal. The actual pixel size is very large in scale and practically device simulation takes long time to simulate pixel behaviour and charging/discharging characteristics of liquid crystal. MixedMode circuit simulation performs both device level simulation and circuit level simulation, in which IGZO TFT test active structure is for device level and TFT pixel (Cst), liquid crystal (Clc) is for circuit level. As a result, users could trace pixel electrode’s voltage during TFT on/off periods and additionally estimates pixel voltage shift by active device characteristics such as a-IGZO traps, backlight, and other facts.
MixedMode syntax description Mixedmode circuit description starts with .BEGIN statement and ends with .END statement. Some passive elements (Cst and Clc) are connected to Victory Device TFT structure in ATFT element. Here, Cst is storage capacitance and Clc is liquid crystal capacitance. Both are connected to active IGZO TFT device. Gate, Drain, and Vcom pulse are applied to circuit using “Vname ” statement. For liquid crystal capacitance model, we used simple constant capacitance value. Regarding real LC capacitance model, we can use user-defined two terminal element which is defined in C-interpreter function(tftex14_0.c) and uncomment “bLC ” statement.
The example shows:
Structure formation using Victory Process syntax
Structure loading into Victory Device and region modification to have a region name “GI ” and “channel ”
MixedMode Active IGZO device and circuit element description
Pixel transient simulation
Plotting transient response of pixel
The key command in a-IGZO:TFT Mixedmode pixel simulation is the active device element which is defined in “Aname ” statement between .BEGIN and .END. “atft ” device’s each electrodes name(gate,source,drain) is connected to passive element and time dependent voltage source via node number.
.numeric controls various Mixedmode convergence and iteration during solution. .options fulln sets the numerical method in Mixedmode. Default is full newton method
go internal activates Mixedmode simulation.
After completion of transient simulation, charging and discharging behaviour of LC is plotted.
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