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university:courses:electronics:electronics-lab-21 [29 Oct 2012 16:27] – created Doug Mercer | university:courses:electronics:electronics-lab-21 [13 Jun 2022 20:06] (current) – [Appendix:] Doug Mercer | ||
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- | ====== Activity | + | ====== Activity: CMOS LC Oscillator ====== |
===== Objective: ===== | ===== Objective: ===== | ||
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The goal is to explore the use of the high gain inverting CMOS amplifier in a LC oscillator. | The goal is to explore the use of the high gain inverting CMOS amplifier in a LC oscillator. | ||
- | ====== | + | ====== High gain inverting amplifier ====== |
===== Materials: ===== | ===== Materials: ===== | ||
- | Analog Discovery Lab hardware\\ | + | ADALM2000 Active Learning Module\\ |
Solder-less breadboard\\ | Solder-less breadboard\\ | ||
Jumper wires\\ | Jumper wires\\ | ||
- | 2 - 0.1uF capacitor (104)\\ | + | 2 - 0.1 uF capacitor (104)\\ |
- | 1 - 47Ω resistor\\ | + | 1 - 47 Ω resistor\\ |
1 - 1 mH inductor\\ | 1 - 1 mH inductor\\ | ||
- | 1 - CD4069A, CD4069UB or 74HCU04 unbuffered hex inverter (be sure not to use the buffered 74HC04 version) Alternatively three simple CMOS inverters can be built using the CD4007 transistor array. Note the appendix at the end.\\ | + | 1 - CD4069A, CD4069UB or 74HCU04 unbuffered hex inverter (be sure not to use the buffered 74HC04 version) Alternatively three simple CMOS inverters can be built using the CD4007 transistor array. Note the appendix at the end. |
===== Background: ===== | ===== Background: ===== | ||
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===== Directions: ===== | ===== Directions: ===== | ||
- | First build the simple example shown figure 2 to test the input to output transfer function of the simple CMOS amplifier. The green boxes indicate connections to the connector on Analog Discovery. Connect Vp (+5V) power to V< | + | First build the simple example shown figure 2 to test the input to output transfer function of the simple CMOS amplifier. The green boxes indicate connections to the connector on The ADALM2000. Connect Vp (+5V) power to V< |
{{ : | {{ : | ||
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===== Hardware Setup: ===== | ===== Hardware Setup: ===== | ||
- | Configure the waveform generator for a 1 KHz triangle wave with 2V amplitude and 2.5V offset. Both scope channels should be set to 1V/Div. | + | Configure the waveform generator for a 1 KHz triangle wave with 4V amplitude |
===== Procedure: ===== | ===== Procedure: ===== | ||
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Measure the slope of the output and calculate the DC gain of the amplifier as the ratio of the change in the output voltage to the change in input voltage at the center of the output swing (i.e. around 2.5V). Remember this should be a negative number because the amplifier inverts. | Measure the slope of the output and calculate the DC gain of the amplifier as the ratio of the change in the output voltage to the change in input voltage at the center of the output swing (i.e. around 2.5V). Remember this should be a negative number because the amplifier inverts. | ||
- | ====== | + | ====== Adding LC resonator ====== |
On your solder-less breadboard construct the filter network shown in figure 4 below. Using the Network (Bode) analyzer tool measure the gain and phase response of the LC network. | On your solder-less breadboard construct the filter network shown in figure 4 below. Using the Network (Bode) analyzer tool measure the gain and phase response of the LC network. | ||
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===== Hardware Setup: ===== | ===== Hardware Setup: ===== | ||
- | Configure the Network (Bode) analyzer for 2 log decades, end frequency of 100 KHz, a max gain of 2X, run time of 10 sec, offset of 0 V and an amplitude of 1 V. Run a single sweep and save the data to a file. | + | Configure the Network (Bode) analyzer for 2 log decades, end frequency of 100 KHz, a max gain of 2X, run time of 10 sec, offset of 0 V and an amplitude of 2 V peak-to-peak. Run a single sweep and save the data to a file. |
=====Question: | =====Question: | ||
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Based on the frequency response of the LC network, at what frequency do you think the circuit will oscillate? | Based on the frequency response of the LC network, at what frequency do you think the circuit will oscillate? | ||
- | ====== | + | ====== Placing LC network in feedback of amplifier ====== |
{{ : | {{ : | ||
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Below is the schematic and pinout for the CD4007: | Below is the schematic and pinout for the CD4007: | ||
- | {{ : | + | {{ : |
<WRAP centeralign> | <WRAP centeralign> | ||
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Two of these inverters can be used to construct the LC oscillator in figure 5 for example. | Two of these inverters can be used to construct the LC oscillator in figure 5 for example. | ||
+ | |||
+ | **Return to Lab Activity [[university: | ||