Analog and Digital Signals - Analog Electronics - Lecture Slides, Slides of Computer Science

Download Analog and Digital Signals - Analog Electronics - Lecture Slides and more Slides Computer Science in PDF only on Docsity! Continuous-time, continuous-valued Discrete-time, continuous-valned signal (analog) signal alll Discrete-time, discrete-valued (digital) signal Continnous-time, discrete-valued signal 1 Docsity.com 2 Analog Signals are links to the real world Transreceiver Docsity.com 5 Transfer Characteristics (2) • Gain = Slope • To operate amplifier in its linear region, the input must be kept small enough Real Transfer Characteristics • Each circle represents a different DC component for the input and output signals – called an operating point • Location of operating point has an effect on • input signal range • amplifier gain magnitude • amount of distortion Docsity.com 6 Operating Point (1) Voltage gain, output DC voltage, allowable input magnitude range are affected Operating Point (2) Derivative of transfer characteristic gives measure of amplifier gain linearity (and distortion) Input and output signal amplitude ranges are maximized when operating point is near middle of linear region Docsity.com 7 Signal Convention (1) • DC magnitudes in uppercase symbol and subscript – Example: ID, VD • Ac signal quantities in lowercase symbol & subscript – Example: id(t), vd(t) • Total DC + ac signal quantities in lowercase symbol, uppercase subscript – Example: iD(t), vD (t) Signal Convention (2) In general vD(t) = VD + vd(t) iC(t) = IC + ic(t) Docsity.com 10 Loaded Voltage Amplifier Ro Avi + vi - + vo - Ri + RL Rsvs + Lo L is i s o RR R RR R Av v ++= Ideal Current Amplifier Real Current Amplifier Aii ii io Aii ii io Ri Ro Docsity.com 11 Loaded Ideal Current Amplifier Ai i s o = Aii RL ii Rsis io Loaded Current Amplifier Aii RL ii RSis io Ri Ro Lo o is s s o RR R RR R Ai i ++= Docsity.com 12 To determine Input Resistance Ri Ro Avi + vi - + vo - Ri + • Apply input voltage vi (or input current ii) • Determine the input current ii (or input voltage vi) Then Ri = vi / iiAii ii io Ri Ro ii + vi - Voltage Amplifier Current Amplifier To determine Output Resistance Ro Ro Avi + vi - + vx - Ri + • Kill the input signal (set vi or ii to zero) • Apply a test voltage vx to the output node • Determine the current ix that the source delivers to the circuit Then Ro = vx / ix Aii ii ixRi Ro ii + vi - Voltage Amplifier Current Amplifier + vx - ix Docsity.com