Uditha Reddy Level 1 Report

23 / 3 / 2025

Electronic Design

TASK 1: Engineer’s Swiss Army Knife (MATLAB Onramp Course)

For this task, I created a Matlab account and completed the MATLAB Onramp course and obtained the certification for the same.

Key Learnings: Basic Commands • Use >> in Command Window to run commands • = assigns values to variables • ; hides output • clear removes all variables • clc clears the command window • save and load to handle MAT-files • Built-in functions: pi, abs, trig functions Arrays and Matrices • Use [] to create arrays • Spaces → row vector, Semicolons → column vector • Use colon : for ranges (e.g., 1:2:9) • Use linspace(start, end, num_elements) for evenly spaced vectors • ' transposes a vector • Single index reads columns first Plotting • plot(x, y) to plot data • Customize plot with colors, line styles, markers • hold on to plot multiple lines on same axes • hold off to reset • Use name-value pairs for plot settings (e.g., LineWidth=5)

Final Project - Star Spectrum In this MATLAB project, we can find out if a star is moving toward or away from Earth by studying its light spectrum. Stars give off light, and some of that light gets absorbed at specific wavelengths—like the hydrogen alpha line at 656.3 nanometers. If this line appears at a different wavelength in the star's spectrum, it means the light has shifted due to the Doppler effect. A shift toward a longer wavelength (redshift) means the star is moving away from Earth, while a shift to a shorter wavelength (blueshift) means it’s coming closer. Using MATLAB, we load and visualize data from a file to see this shift and calculate the star’s speed.

TASK 2: Band Pass Filter

Filters are used to change the frequency of signals. • Low pass filter (LPF): LPF allows signals with frequencies below a set cutoff frequency to pass through while blocking higher frequencies. • High Pass Filter (HPF): This filter allows only higher-frequency signals above a specific cut-off frequency. • Band Pass Filter (BPF): A band-pass filter is a type of filter that allows signals within a specific range of frequencies to pass through while blocking frequencies outside that range.

Active bandpass filters use active components such as operational amplifiers. Designing a second order band pass filter using IC747 that amplifies the signal to roughly 1.5 times the original signal. Cutoff range between 4kHz and 10kHz.

TASK 3: SPICE Code

SPICE code refers to the text-based input used by SPICE software. It's a structured way to describe the components, interconnections, and desired analysis parameters of an electronic circuit. Inspite of having so many GUI softwares where we can just pick and place the components and simulate them, we use spice code in VLSI simulation because when we use Cadence, Mentor Graphics etc, we might face simulation issues.

CMOS Inverter:

CMOS AND:

CMOS OR:

TASK 4: Voltage Multiplier

The voltage multiplier using capacitor pumps and a 555 Timer IC operates by converting a low DC voltage (9V) into higher DC voltages (first 18V, then 27V) through a series of charge-pump stages driven by a square wave. In this setup, the 555 Timer is configured as an astable multivibrator to produce a continuous square wave signal, typically in the kilohertz range. This oscillating signal is used to alternately charge and discharge capacitors through diodes, effectively shifting voltage levels. In the first stage, the circuit doubles the 9V input to approximately 18V using a diode-capacitor arrangement known as a voltage doubler. The output of this stage then feeds into a second similar stage, which adds another 9V, resulting in a final output of approximately 27V. Each diode ensures current flows in the correct direction, while capacitors store and transfer the charge.

TASK 5: The Power Shuffle: Buck-Boost Edition

Boost converters increase the voltage of a power source. For example a boost converter could take a 5V power source and boost it up to 25V. Typically, you find DC-DC boost converters in battery chargers or solar panels. They can also be used to supply components with different operating voltages from the same battery.

Buck converters reduce the voltage of a power supply. This is a power electronics circuit that steps down the DC voltage to a level determined by the choice of components in your circuit. Unlike linear regulators that reduce the voltage by dissipating power as heat, buck converters reduce the voltage by increasing the current.