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Lecturer Kent Bertilsson Kent.Bertilsson@miun.se S-Building Office S206 Phone 060-148915. Analog Electronics. http://www.miun.se/personal/kent.bertilsson/Courses/AnalogElectronics.htm Thomas L. Floyd, "Electronic Devices - Conventional Current Version" ISBN: 0-13-615581-2
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Lecturer Kent Bertilsson Kent.Bertilsson@miun.se S-Building Office S206 Phone 060-148915 Analog Electronics http://www.miun.se/personal/kent.bertilsson/Courses/AnalogElectronics.htm • Thomas L. Floyd, "Electronic Devices - Conventional Current Version"ISBN: 0-13-615581-2 • Don Manchini, "Op Amps for Everyone" -Free downloadable pdf Lab teacher Krister Hammarling Krister.Hammarling@miun.se S-Building Office S207
Examination This analog electronics is given as a stand alone course but also as one part of the Measurement System course. • 12 x 2h scheduled lectures • 10 Lectures • 2 times for solving problems • As appeared in the plan (Not as shown in schedule) • 4 x 4h scheduled laboratory classes completing 3 tasks that should completed and handed in to the laboratory teacher. • A written exam will be held 27th October
Block Diagram • Electronic systems is often described by block diagram Antenna Amplifier Filter Analog to digital conversion
Time domain vs Frequency domain • Every signal can be described both in the time domain and the frequency domain. • A periodic signal (in the time domain) can in the frequency domain be represented by: • A peak at the fundamental frequency for the signal, fs=1/T • and multiples of the fundamental f1,f2,f3,…=1xfs ,2xfs ,2xfs V T=1/fst V fs 2 fs 3 fs 4 fs 5 fs f
Time domain vs Frequency domain • Every signal can be described both in the time domain and the frequency domain. • A non periodic (varying) signal time domain is spread in the frequency domain. • A completely random signal (white noise) have a uniform frequency spectra V fs 2 fs 3 fs 4 fs 5 fs f V Noise f
Transfer function • The transfer function is the relation between the amplitude for the output and input in the frequency domain. • H(20kHz)=10 mean that for a 20kHz signal the output is ten times larger than the input. • H(f) is of course continuous function H 10 5 0 f
Filter • A filter is a circuit that let some frequencies pass and block others. • Low pass • High pass • Band pass • Band stop H f H f H f H f
jω-method • The jω-method is a very powerful tool making it possible performing advanced frequency dependent (alternating current, AC) functions using the same rules that applies for direct current (DC) Resistor Capacitor Inductor Symbol Reactance
jω-method • Impedance calculations can be performed in the same way as for normal resistances. R L R L
RC - filter Calculate the transfer function H(ω) What is the output voltage and power level at the cut-off frequency? R VIn C VOut
Amplifier • Voltage amplification • Current amplification • Power amplification IIN IOut PIN VIn VOut POut
Decibel, dB decibel, dB is very useful expressing amplification (and attenuation) (Under assumption that RInAmp=RLoad)
Bode Diagram • Absolute decibel value and phase of the transfer function is plotted against a logarithmic frequency axis
RC-filter example Draw an asymptotic bode diagram for the RC filter. R VIn C VOut
Bode diagram • Complicated expressions can be factorized into sub-expressions as Const Differentiator Integrator Zero Pole
Bode diagram • According to logarithmic laws
Example R R2 C VIn R3 VOut Draw an asymptotic bode diagram for the shown filter.
Amplifier model • The amplifier model is often sufficient describing how an amplifier interacts with the environment • RIn – Input impedance • AV – Voltage gain • ROut – Output impedance ROut VIn RIn AVVIn VOut
Bandwidth • The bandwidth is the frequency range where the transferred power are more than 50%. H(f) AVmax 0.707AVmax f1f2f
Distortion • A nonlinear function between UIn and UOut distorts the signal • An amplifier that saturates at high voltages • A diode that conducts only in the forward direction
Noise • Random fluctuation in the signal • Theoretically random noise contains all possible frequencies from DC to infinity • Practical noise is often frequency limited to an upper bandwidth by some filter • A limited bandwidth from the noisy reduce the noise power