Differential amplifier circuits based on carbon nanotube field effect transistors (CNTFETs)

Original publisher: Adelphi, MD : Army Research Laboratory, [2010] OCLC Number: (OCoLC)640093151 Subject: Field-effect transistors. Excerpt: ... 3.2 Circuit Configuration A simple long-tail differential amplifier using two electrically matched CNTFETs and three potentiometers was set up for the initial testing. The long-tail design was chosen for its simplicity to get initial results, while limiting any complications that might arise from the use of a current mirror or other, more complex current source circuit. A schematic of the circuit used is shown in figure 5. V S R S S S S CNTFET CNTFET G G G G D D D D V + + OUT V GS2 V GS1--R R D D Figure 5. Schematic of the long-tail differential amplifier used for initial testing. 3.3 Experimental Setup and Procedure The circuit was set up as pictured in figure 5 with power supplies attached to V, V, and V. S GS1 GS Voltmeters were hooked up to each of the power supplies to monitor the voltages. A fourth voltmeter was hooked up between the V terminals to measure the output voltage. The OUT resistors were tuned so that when V = V, the output voltage ( V ) read 0.0 V. GS1 GS2 OUT For the first measurements, V and V were held constant while V was changed to simulate S GS1 GS2 the analyte. Changing V changed the channel conductance, which is what the presence of an GS2 analyte would do. Multiple experiments were performed with V set to different bias values. GS1 Depending on the reference point ( set by V ), the difference between V and V would GS1 GS1 GS2 cause varying output voltage responses. Four initial sets of measurements were performed on the differential amplifier circuit. In all four cases, the source-drain voltage supplied ( V ) was kept the same at 3 V. The gate reference S voltage ( V ) was changed for each of the four cases while V was swept. The resistance GS1 GS2 values were adjusted for each circuit to tune V to 0 V when V = V. A table with the OUT GS1 GS2 values for each of the four sets of measurements ...