The Design Of A Liquid Crystal Display Circuit ASIC

Based on the commonly used integrated circuit designing flow, the digital and analog portions of a LCD (liquid crystal display) driving circuit are designed. The design of this ASIC (Application Specific Integrated Circuit) is more advanced in power consumption, clock & calendar circuit and reset circuit making it more competitive than similar domestic products.Applying silicon gate technology, the chip has a lower value in power consumption than the products made by aluminum gate technology. The power consumption of the digital circuit is evaluated as 450uW, and the total current is 90uA. The simulation results show that the total current of the analog circuit is 160uA, which is 10 percent lower than other similar products.The commonly used designing flow and basic technology of integrated circuit, such as the cell layout, synthesis, simulation, FPGA verification, automatic layout & routing of the digital circuit, are introduced and analyzed in detail. The layout designing and simulation of the analog circuit are also introduced and analyzed in detail.The designing of the oscillator circuit and detailed layout are specially introduced and analyzed. The simulation results indicate that the oscillator circuit with the CMOS technology producing steady oscillating signal has power consumption as low as 800uW.As a preliminary investigation of the channel automatic routing, some of the channel router algorithm, such as left edge algorithm, the dogleg algorithm, net merge channel router and greedy channel router, are analyzed. With the computer programs, the left edge algorithm and the greedy channel router are performed. A channel example in the LCD driving circuit is used to compare these two and the results routed by hand.The comparison results show that the left edge algorithm can only resolve the channel routing problem without vertical constraints, while the greedy channel router can accomplish the problem with vertical and horizontal constraints. However in aspect of reducing channel height, via number and average route length, the results from the greedy channel router is not as good as the results routed by hand. More studies are required for better algorithm.