Microelectronic Filters

ABSTRACT

Considering oscillator circuits are implemented in almost every electronic product today, these fundamental circuits can be thought of as the foundation for many devices. Oscillator circuits provide clean and dependable signals to drive other devices, so as to provide a reference or clock signal in the form of a square wave, triangle wave, or sine wave. For example, oscillators are used to operate key functionality in metal detectors, radios, and stun guns.

In order to design a collector-coupled BJT oscillator, also known as a relaxation oscillator, a sufficient amount of calculation and simulation time is required. Using PSpice to simulate the collector-coupled BJT oscillator, transient analysis and frequency response curves can be used to determine key signal parameters, such as amplitude, frequency, total harmonic distortion (THD), and DC offset voltage. After simulation, practical implementation can be used to attain these same parameters to determine the percentage error due to factors not accounted for during simulation. For example, affects due to inaccurate component values and attenuation in signal strength from power loss definitely contribute to attaining a nonzero percentage error. However, if time is taken into designing the collector-coupled BJT oscillator, factors such as inaccurate component values can be minimized, and a more ideal output waveform can be generated.

INTRODUCTION

1. Background

An electronic oscillator is a device that produces a periodic signal, such as a square wave, a triangle wave, or a sine wave, so as to provide a clock source or reference signal for another device. Two basic types of oscillators include linear and nonlinear types, where linear oscillators use feedback to manifest a desired output signal, and nonlinear oscillators use