PowerPoint Overheads to Accompany Sedra/Smith Microelectronic Circuits 4/e ©1999 Oxford University Press. Microelectronic Circuits - Fourth Edition Sedra/Smith 0 Fig. 1.13 An amplifier transfer characteristic that is linear except for output saturation. Microelectronic Circuits - Fourth Edition Sedra/Smith 1 Fig. 1.14 (a) An amplifier transfer characteristic that shows considerable nonlinearity. (b) To obtain linear operation the amplifier is biased as shown, and the signal amplitude is kept small. Microelectronic Circuits - Fourth Edition Sedra/Smith 2 Fig. 1.23 (a) Magnitude and (b) phase response of STC networks of the low-pass type. Microelectronic Circuits - Fourth Edition Sedra/Smith 3 Fig. 1.24 (a) Magnitude and (b) phase response of STC networks of the high-pass type. Microelectronic Circuits - Fourth Edition Sedra/Smith 4 Fig. 2.4 The inverting closed-loop configuration. Microelectronic Circuits - Fourth Edition Sedra/Smith 5 Fig. 2.5 Analysis of the inverting configuration Microelectronic Circuits - Fourth Edition Sedra/Smith 6 Fig. 2.21 A difference amplifier. Microelectronic Circuits - Fourth Edition Sedra/Smith 7 Fig. 2.22 Applications of superposition to the analysis of the current circuit of Fig.. 2.21. Microelectronic Circuits - Fourth Edition Sedra/Smith 8 Fig. 2.23 Finding the input resistance of the difference amplifier. Microelectronic Circuits - Fourth Edition Sedra/Smith 9 Fig. 2.24 Representation of the common-mode and differential components of the input signal to a difference amplifier. Note that v1 = vCM - vd/2 and v2 = vCM + vd/2. Microelectronic Circuits - Fourth Edition Sedra/Smith 10 Fig. 2.25 (a) A popular circuit for an instrumentation amplifier. (b) Analysis of the circuit in (a) assuming ideal op-amps. (c) To make the gain variable, R1 is implemented as the series combination of a fixed resister R1f and a variable resistor R1v. Resistor R1f ensures that the maximum available gain is limited. Microelectronic Circuits - Fourth Edition Sedra/Smith 11 Fig. 2.26 Open-loop gain of a typical general-purpose internally compensated op amp. Microelectronic Circuits - Fourth Edition Sedra/Smith 12 Fig. 2.29 (a) Unity-gain follower. (b) Input step waveform. (c) Linearly rising output waveform obtained when the amplifier is slewrate limited. (d) Exponentially rising output waveform obtained when V is sufficiently small so that the initial slope (wtV) is smaller then or equal to SR. Microelectronic Circuits - Fourth Edition Sedra/Smith 13 Fig. 2.30 Effect of slew-rate limiting on output sinusoidal waveforms. Microelectronic Circuits - Fourth Edition Sedra/Smith 14 Fig. 3.1 The ideal diode: (a) diode circuit symbol; (b) i-v characteristic; (c) equivalent circuit in the reverse direction; (d) equivalent circuit in the forward direction. Microelectronic Circuits - Fourth Edition Sedra/Smith 15 Fig. 3.3 (a) Rectifier circuit. (b) Input waveform. (c) Equivalent circuit when (d) Equivalent circuit when v1 0 (e) Output waveform. Microelectronic Circuits - Fourth Edition Sedra/Smith 16 Fig. 3.7 The i-v characteristic of a silicon junction diode. Microelectronic Circuits - Fourth Edition Sedra/Smith 17 Fig. 3.8 The diode i-v relationship with some scales expanded and others compressed in order to reveal details. Microelectronic Circuits - Fourth Edition Sedra/Smith 18 Fig. 3.10 Simplified physical structure of the junction diode. (Actual geometries are given on Appendix A.) Microelectronic Circuits - Fourth Edition Sedra/Smith 19 Fig. 3.12 (a) The pn junction with no applied voltage (open-circuited terminals). (b) The potential distribution along an axis perpendicular to the junction. Microelectronic Circuits - Fourth Edition Sedra/Smith 20 Fig. 3.13 The pn junction excited by a constant-current source I in the reverse direction. To avoid breakdown, I is kept smaller than Is. Note that the depletion layer widens and the barrier voltage increases by Vr volts, which appears between the terminals as a reverse voltage. Microelectronic Circuits - Fourth Edition Sedra/Smith 21 Fig. 3.14 The charge stored on either side of the depletion layer as a function of the reverse voltage Vr. Microelectronic Circuits - Fourth Edition Sedra/Smith 22 Fig. 3.16 The pn junction excited by a constant-current source supplying a current I in the forward direction. The depletion layer narrows and the barrier voltage decreases by V volts, which appears as an external voltage in the forward direction. Microelectronic Circuits - Fourth Edition Sedra/Smith 23 Fig. 3.17 Minority-carrier distribution in a forward-biased pn junction. It is assumed that the p region is more heavily doped than the n region; NA ND. Microelectronic Circuits - Fourth Edition Sedra/Smith 24 Fig. 3.18 A simple diode circuit. Microelectronic Circuits - Fourth Edition Sedra/Smith 25 Fig. 3.19 Graphical analysis of the circuit in Fig. 3.18. Microelectronic Circuits - Fourth Edition Sedra/Smith 26 Fig. 3.20 Approximating the diode forward characteristic with two straight lines. Microelectronic Circuits - Fourth Edition Sedra/Smith 27 Fig. 3.21 Piecewise-linear model of the diode forward characteristic and its equivalent circuit representation. Microelectronic Circuits - Fourth Edition Sedra/Smith 28 Fig. 3.23 Development of the constant-voltage-drop model of the diode forward characteristics. A vertical straight line (b) is used to approximate the fast-rising exponential. Microelectronic Circuits - Fourth Edition Sedra/Smith 29 Fig. 3.24 The constant-voltage-drop model of the diode forward characteristic and its equivalent circuit representation. Microelectronic Circuits - Fourth Edition Sedra/Smith 30 Fig. 3.25 Development of the diode small-signal model. Note that the numerical values shown are for a diode with n = 2. Microelectronic Circuits - Fourth Edition Sedra/Smith 31 Fig. 3.26 Equivalent circuit model for the diode for small changes around bias point Q. The incremental resistance rd is the inverse of the slope of the tangent at Q, and VD0 is the intercept of the tangent on the vD axis (see Fig. 3.25). Microelectronic Circuits - Fourth Edition Sedra/Smith 32 Fig. 3.27 The analysis of the circuit in (a), which contains both dc and signal quantities, can be performed by replacing the diode with the model of Fig. 3.26, as shown in (b). This allows separating the dc analysis [the circuit in (c)] from the signal analysis [the circuit in (d)]. Microelectronic Circuits - Fourth Edition Sedra/Smith 33 Fig. 3.30 Circuit symbol for a zener diode. Microelectronic Circuits - Fourth Edition Sedra/Smith 34 Fig. 3.31 The diode i-v characteristic with the breakdown region shown in some detail. Microelectronic Circuits - Fourth Edition Sedra/Smith 35 Fig. 3.32 Model for the zener diode. Microelectronic Circuits - Fourth Edition Sedra/Smith 36 Fig. 3.36 Block diagram of a dc power supply. Microelectronic Circuits - Fourth Edition Sedra/Smith 37 Fig. 3.37 (a) Half-wave rectifier. (b) Equivalent circuit of the half-wave rectifier with the diode replaced with its battery-plusresistance model. (c) transfer characteristic of the rectifier circuit. (d) Input and output waveforms, assuming that rD R. Microelectronic Circuits - Fourth Edition Sedra/Smith 38 Fig. 3.38 Full-wave rectifier utilizing a transformer with a center-tapped secondary winding. (a) Circuit. (b) Transfer characteristic assuming a constant-voltage-drop model for the diodes. (c) Input and output waveforms. Microelectronic Circuits - Fourth Edition Sedra/Smith 39 Fig. 3.39 The bridge rectifier: (a) circuit and (b) input and output waveforms. Microelectronic Circuits - Fourth Edition Sedra/Smith 40 Fig. 3.41 Voltage and current waveforms in the peak rectifier circuit with CR T. The diode is assumed ideal. Microelectronic Circuits - Fourth Edition Sedra/Smith 41 Fig. 3.46 A variety of basic limiting circuits. Microelectronic Circuits - Fourth Edition Sedra/Smith 42