| Both sides previous revisionPrevious revisionNext revision | Previous revision |
| university:courses:electronics:electronics-lab-pn-junction-cap [12 Jul 2019 12:58] – Pop Andreea | university:courses:electronics:electronics-lab-pn-junction-cap [27 Jan 2021 22:36] (current) – use wp> interwiki links Robin Getz |
|---|
| For further reading on PN junction depletion region: | For further reading on PN junction depletion region: |
| |
| [[http://en.wikipedia.org/wiki/Depletion_region|Depletion Region]] | [[wp>Depletion_region|Depletion Region]] |
| |
| ===== Materials: ===== | ===== Materials: ===== |
| ===== Hardware Setup: ===== | ===== Hardware Setup: ===== |
| |
| Using the Network Analyzer instrument in the Scopy software obtain a gain (attenuation) vs. frequency plot from 5 kHz to 10 MHz. Scope channel 1 is the "filter" input and scope channel 2 is the "filter" output. Set AWG offset to 1V and the Amplitude to 200mV. The offset value is not important at this point when measuring a simple real capacitor but will be used as the reverse bias voltage when we measure diodes in later steps. Set the vertical scale to start at 1dB to -50 dB range. Run a single sweep and export the data to a .csv file. You should notice a high pass characteristic that has a high attenuation at very low frequencies where the impedance of the capacitor is large compared to R<sub>1</sub>. At the very high end of the frequency sweep there should be a relatively flat region where the impedance of the C<sub>1</sub>, C<sub>m</sub>capacitive voltage divider is much lower than R<sub>1</sub>. | Using the Network Analyzer instrument in the Scopy software obtain a gain (attenuation) vs. frequency plot from 5 kHz to 10 MHz. Scope channel 1 is the "filter" input and scope channel 2 is the "filter" output. Set AWG offset to 1V and the Amplitude to 200mV peak-to-peak . The offset value is not important at this point when measuring a simple real capacitor but will be used as the reverse bias voltage when we measure diodes in later steps. Set the vertical scale to start at 1dB to -50 dB range. Run a single sweep and export the data to a .csv file. You should notice a high pass characteristic that has a high attenuation at very low frequencies where the impedance of the capacitor is large compared to R<sub>1</sub>. At the very high end of the frequency sweep there should be a relatively flat region where the impedance of the C<sub>1</sub>, C<sub>m</sub>capacitive voltage divider is much lower than R<sub>1</sub>. |
| |
| {{ :university:courses:electronics:apn_f3.png?600 |}} | {{ :university:courses:electronics:apn_f3.png?600 |}} |
| {{ :university:courses:electronics:apn_e1.png?220 |}} | {{ :university:courses:electronics:apn_e1.png?220 |}} |
| |
| [[http://en.wikipedia.org/wiki/Voltage_divider#Capacitive_divider|Capacitive Dividers]] | [[wp>Voltage_divider#Capacitive_divider|Capacitive Dividers]] |
| |
| ===== Directions Step 2: ===== | ===== Directions Step 2: ===== |
| <WRAP round download> | <WRAP round download> |
| ** Lab Resources ** | ** Lab Resources ** |
| * Fritzing files: [[ https://minhaskamal.github.io/DownGit/#/home?url=https://github.com/analogdevicesinc/education_tools/tree/master/m2k/fritzing/volt_dep_cap_pn_junc_bb | v_dep_pn_bb]] | * Fritzing files: [[downgit>education_tools/tree/master/m2k/fritzing/volt_dep_cap_pn_junc_bb | v_dep_pn_bb]] |
| * LTSpice files: [[ https://minhaskamal.github.io/DownGit/#/home?url=https://github.com/analogdevicesinc/education_tools/tree/master/m2k/ltspice/v_dep_pn_ltspice | v_dep_pn_ltspice]] | * LTSpice files: [[downgit>education_tools/tree/master/m2k/ltspice/v_dep_pn_ltspice | v_dep_pn_ltspice]] |
| </WRAP> | </WRAP> |
| |
| ==== For Further Reading: ==== | ==== For Further Reading: ==== |
| [[http://en.wikipedia.org/wiki/Varicap|The Varactor Diode, Varicaps]] | [[wp>Varicap|The Varactor Diode, Varicaps]] |
| |
| **Return to the Lab Activity [[university:courses:electronics:labs|Table of Contents]]** | **Return to the Lab Activity [[university:courses:electronics:labs|Table of Contents]]** |
