Praveen Subramani design + technology + cities

Analog Circuit Design

I have significant experience in the design and construction of analog electronic circuitry on breadboards, protoboards, and printed circuit boards (PCBs). In my coursework and work experience, I have designed multistage wideband amplifiers from discrete transistors, designed and laid out PCBs for hardware prototypes, and completed design and implementation for devices ranging from audio players to optical encoders. Some samples are shown below.

In Solid State Circuits, I designed and built devices such as a wideband amplifier and transimpedance amplifier. The wideband amplifier had a midband gain of 400 and an upper half power frequency of over 6 MHz. Six 2N3904 bipolar junction transistors were used to construct a four stage amplifier consisting of an input and output emitter follower and two intermediate gain stages composed of cascodes. The schematic and breadboarded prototype are shown below.

Wideband AmplifierWideband Amplifier Schematic

Breadboarded Wideband AmplifierBreadboarded Prototype of Wideband Amplifier

In Microelectronic Devices & Circuits, I designed an optical converter for converting incoming photon intensity into useful electrical signals understandable by digital processors. This project also involved sizing MOS transistor channel widths and lengths to achieved the desired performance and meet specifications.

Optical EncoderOptical Encoder Block Diagram

In my Circuits & Electronics coursework I designed and constructed a music player that sampled audio signals from a digital memory bank at an 8 kHz rate, converted the digital signals to analog through a DAC, filtered the resulting signal, and amplified it to be output through a speaker (block diagram shown below).

Audio Player Block Diagram

Audio Player Block Diagram