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— | university:courses:alm1k:alm-lab-3m [26 Apr 2019 13:35] – [Questions:] Antoniu Miclaus | ||
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+ | ======Activity 3M. The MOS transistor connected as a diode====== | ||
+ | |||
+ | =====Objective: | ||
+ | |||
+ | The purpose of this activity is to investigate the forward current vs. voltage characteristics of a MOS field effect transistor (NMOS and PMOS) connected as a diode. | ||
+ | |||
+ | =====Notes: | ||
+ | |||
+ | As in all the ALM labs we use the following terminology when referring to the connections to the M1000 connector and configuring the hardware. The green shaded rectangles indicate connections to the M1000 analog I/O connector. The analog I/O channel pins are referred to as CA and CB. When configured to force voltage / measure current -V is added as in CA-V or when configured to force current | ||
+ | |||
+ | Scope traces are similarly referred to by channel and voltage / current. Such as CA-V , CB-V for the voltage waveforms and CA-I , CB-I for the current waveforms. | ||
+ | |||
+ | =====The Diode Connected NMOS transistor===== | ||
+ | |||
+ | ====Materials: | ||
+ | |||
+ | ADALM1000 Hardware Module\\ | ||
+ | Solder-less Breadboard\\ | ||
+ | 1 - 100 Ω Resistor\\ | ||
+ | 1 - Small signal enhancement mode NMOS transistor (CD4007 CMOS array)\\ | ||
+ | 1 - Small signal enhancement mode PMOS transistor (CD4007 CMOS array) | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | <WRAP centeralign> | ||
+ | |||
+ | ====NMOS Directions: | ||
+ | |||
+ | The current vs. voltage characteristics of the gate source of an enhancement mode NMOS transistor can be measured using the ALM1000 hardware and the following connections. Set up the breadboard with the channel A generator attached to one end of resistor R< | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | <WRAP centeralign> | ||
+ | |||
+ | ====Hardware Setup:==== | ||
+ | |||
+ | The waveform generator should be configured for a 100 Hz triangle wave with 5 volt Max and 0 V Min. The CA-I signal trace measures the current in the resistor (and in the transistor). Scope channel B is connected to measure the voltage across the transistor. The current flowing through the transistor is the current measured in channel A (CA-I) or the Math trace voltage difference between CB-V - CA-V divided by the resistor value (100 Ω). | ||
+ | |||
+ | ====Procedure: | ||
+ | |||
+ | Load the captured data into Excel and calculate the current. Calculate and plot the current vs. the voltage across the transistor (V< | ||
+ | |||
+ | ====Questions: | ||
+ | |||
+ | By plotting the data measured for I< | ||
+ | Are these V< | ||
+ | |||
+ | ====PMOS Directions: | ||
+ | |||
+ | Repeat the experiment using one of the PMOS devices in the CD4007. The connections are similar and as shown on figure 2 below. The Source of M< | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | <WRAP centeralign> | ||
+ | |||
+ | ====Hardware Setup:==== | ||
+ | |||
+ | The channel A generator should be configured for a 100 Hz triangle wave with 5 volt Max and 0 V Min. The CA-I signal trace measures the current in the resistor (and in the transistor). The scope channel B is connected to measure the voltage across the transistor. The current flowing through the transistor is the current measured in channel A (CA-I) or the Math trace voltage difference between CB-V - CA-V divided by the resistor value (100 Ω). | ||
+ | |||
+ | ====Procedure: | ||
+ | |||
+ | Load the captured data in to Excel and calculate the current. Calculate and plot the current vs. the voltage across the transistor (V< | ||
+ | |||
+ | ====Questions: | ||
+ | |||
+ | By plotting the data measured for I< | ||
+ | Are these V< | ||
+ | How do the V< | ||
+ | |||
+ | **Resources: | ||
+ | * LTSpice files: [[ https:// | ||
+ | * Fritzing files: [[ https:// | ||
+ | |||
+ | **For Further Reading:** | ||
+ | |||
+ | http:// | ||
+ | http:// | ||
+ | |||
+ | **Return to ALM Lab Activity [[university: | ||