Summary
I modified a broken microwave to be used as a user-safe UV-C sanitizing device that is effective against SARS-CoV-2, the virus responsible for the coronavirus disease. The use of a microwave ensures that the user will never be exposed to harmful doses of UV-C light by making use of the safety features that are inherent in a microwave. To make this device as safe as possible, it fully operates without the high voltage inverter circuit board and the magnetron. Achieving this required designing an external circuit that mimics the signals sent by the optocoupler circuit in the inverter circuit board to the microwave’s microcontroller.
Summary
I designed a bus-powered USB headphone amplifier that is capable of driving over-the-ear headphones. This headphone amplifier is based on two ICs from Texas Instruments: the PCM2706C which is used for the USB interface and the PCM5102A for the high performance external DAC. The process involved component selection, analyzing component datasheets, applying methods of minimizing noise, schematic drawing and PCB design in Altium Designer, along with soldering and troubleshooting.
Abstract
The design challenge of this two-man team project was to create a high-speed transistor level 8-bit hierarchical carry-lookahead adder that is able to achieve a higher performance compared to the ripplecarry adder in Cadence Virtuoso. We implemented the 8-bit carry-lookahead adder by using 4-bit carry-lookahead generator blocks that are responsible for computing the carryout, group propagate, and group generate bits. This architecture also includes the sum block, which computes the sum, propagate, and generate bits based on the inputs and the carry-in. The design process includes hand-designing the schematic, performing partial layout, DRC/LVS checks, and parasitic extractions. The design achieved a maximum clock speed of 6.22GHz pre-extraction and a 4.35GHz post-extraction using a 45nm process.
