EE210 Digital Electronics Class Lecture 2 September 03, 2008. Sedra/Smith Microelectronic Circuits 5/e Oxford University Press. Introduction to Electronics. 3. In This Class. We Will Discuss Following Topics : 1.1 Signals Thévenin & Norton Theorem (Append. C)
Oxford University Press
We Will Discuss Following Topics :
Thévenin &Norton Theorem (Append. C)
1.2 Frequency Spectrum of Signals
1.3 Analog and Digital Signals
vs (t) = Rsis(t)
Two alternative representations of
a signal source: (a) the Thévenin form, and
(b) the Norton form.
Points to Note:
vs (t) = Rsis(t)
Apply Thévenin’s Theorem to Simplify A BJT Circuit
An arbitrary voltage signal vs(t).
Signal is a Quantity That Varies in Time.
Information is Contained in the Change in Magnitude as Time Progresses.
Difficult to Characterize Mathematically
Sine-wave voltage signal of amplitude Va and frequency f = 1/T Hz. The angular frequency ω= 2πf rad/s.
v(t) = 4V/π (sin ωot + 1/3 sin 3 ωot + 1/5 sin 5 ωot + …)
with ωo = 2 π/ T is Fundamental Frequency
Sinusoidal Components Makeup Frequency Spectrum
And Provides Frequency Spectrum as a Continuous Function of Frequency, Such As:
Periodic Signals Consists of Discrete Freq.
Non-Periodic Signals Contains ALL Freq.
Sampling The Continuous-time Analog Signal in (a) Confined to Short Segments of Frequency, e.g., Audio Band is 20 Hz to 20kHzResults in The Discrete-time Signal in(b)
To use N Binary Digits (bits) to Represent Each Sample of The Analog Signal, the Digitized Sample Value Can be as:
D = b0 20 + b1 21 + b2 22 + … + bN-1 2N-1
b0 , b1 ,… bN-1 are N bits with value 0 or 1
b0 is LSB and bN-1 is MSB
Binary Number Written as: bN-1 bN-2 … b0
Block-diagram Representation Of The Analog-to-digital Affects the Type of Digital Signal Produced and Also Affects the Complexity of Dig. Circuits Converter (ADC) – A Building Block of Modern Electronic Systems
We Will Continue to Discuss:
Chapter 1: Introduction to Electronics
1.7 Logic Inverters
1.8 Circuit Simulation Using SPICE