PC and microcontroller-based current-voltage controller for electronic transport characterization of field effect transistors.

Date

4-2010

Degree

Bachelor of Science in Applied Physics

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Nelio C. Altoveros

Abstract

A hardware-software system for controlling voltage and measuring current for characterization of field effect transistor electronic transport was developed and tested. The main controller used is a microcontroller which was connected to a computer via serial communication. The microcontroller program was developed using ZDSII development environment encoded in C language. Visual Basic was utilized to develop the graphical user interface. The picoammeter was programmed using SCPI programming. The main unit of the voltage controller is a calibrated 16 bit Digital/Analog Converter which exhibited a linear correlation of 1 for values of decimal coded input and output voltage. The DAC showed a 0.479% error percentage for its voltage output. The developed voltage-current controller reads at a sampling rate of 10 samples per minute due to the length of time the picoammeter utilizes in its zero checking and zero correction process. The reading of the developed system is highly precise with a standard deviation of only 6.995x 10-07 IAA for the current values and 8.0x10-°5 V for the voltage values. The developed system was used to generate transfer characteristic curves of a Field Effect Transistor array. Each of the four N-type JFETs was characterized by gathering 30 data points per sampling at a rate of 10 samples per minute at room temperature. The values of the drain current Id, were measured as the gate voltage Vg, was ramped from -0.5V to 1.8V at increments of 0.1V. The measured values were graphed to generate the transfer characteristic curves for the FET array and to determine the cutoff voltage Vgsoff for the field effect transistors. The obtained transfer characteristic curves for the test FETs were similar to the curves specified by the manufacturer's datasheet, as well as the specified Vgs(off) which is -0.5V. Thus, the developed system can correctly characterize a field effect transistor for verification of its electronic transport characteristics.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

This document is currently not available here.

Share

COinS