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Unformatted text preview: ECE 327: Electronic Devices and Circuits Laboratory I Procedure for Lab 6 (Digital-to-Analog Conversion (DAC) Lab) SEE LAB BOOK . The questions you must answer in your report are given in the book. Regulated power supply: BY NOW , you should be using a 10 V DC regulated supply for the TRANS- MITTER . You ALSO need one for your RECEIVER . See the supplementary text for details. To ensure good performance, pay attention to bypass capacitors. Bypass capacitors: Unless otherwise noted, bypass capacitors terminate at 0 V DC . Construction: YOU WILL KEEP EVERYTHING that you build in this laboratory. Build your circuits to be clean , accessible , and COMPACT . TRY TO BUILD ENTIRE RECEIVER IN SAME BREADBOARD “ COLUMN .” Be sure to make the PWM demodulator output EASY TO FIND in later laboratories. REPORT: You do NOT need to report on the nonpositive steps of the procedure.-2. Build a second 10 V DC LM317 voltage regulator for your RECEIVER (i.e., your PWM demodulator). • See supplementary text for details. • Use ∼ . 1 μ F bypass capacitor at 15 V DC input near input pin. • Use ∼ 1 μ F bypass capacitor at 10 V DC output (across rails is fine). – A . 47 μ F bypass capacitor near components across each breadboard rail will be sufficient. – An additional ∼ 1 μ F bypass capacitor at the Adjust pin is a good idea. • ISOLATE a set of supply rails for your receiver. – Your transmitter and receiver my share ground rails but SHOULD NOT share 10 V rails. – FROM NOW ON , use receiver supply rails ( except for the infrared LED).-1. This lab requires THREE FET analog switches. Use one or more CD4066 parts for these switches— TEST SWITCHES BEFORE continuing. • Construct the testing circuit shown below. Use R = 1 kΩ and connect V DD = 10 V and V SS = 0 V. 10 V 0 V R R I/O Z I/O Z CONTROL Z I O CONTROL = ⇒ I O 0 V = ⇒ 10 V 0 V 10 V = ⇒ 5 V 5 V • When you connect CONTROL to 0 V or 10 V, use a 1 k Ω resistor (for safety). • For 0 V control , use DMM to verify switch input sees 10 V and switch output sees 0 V. • For 10 V control , use DMM to verify input and output BOTH see the same 5 V. • TEMPORARILY connect control to 30 kHz clock and verify no switch delay . • Repeat until you find THREE working switches. • DISCONNECT switch testing circuit. You may leave V DD and V SS connected. 0. This lab requires TWO CMOS inverters. Find them on a CD4049 — TEST INVERTERS BEFORE CONTINUING • Connect V DD to 10 V and V SS to 0 V. • Using a 1 kΩ resistor (for safety), connect inverter input to 10 V; use DMM to verify 0 V output. • RE connect 1 kΩ resistor at inverter input to 0 V; use DMM to verify 10 V output. • Connect inverter input to 30 kHz 555 clock and use oscilloscope to verify output is correct....
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- Fall '08
- power supply, Input/output, Switched-mode power supply