In this chapter, you will learn about: Ideal & practical diodes; terminal characteristics of junction diodes; DC load line and quiescent conditions; piecewise linear model; small signal analysis of diodes; dynamic resistance, AC resistance; capacitance and switching response. | Dr. Nasim Zafar Electronics 1 EEE 231 – BS Electrical Engineering Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad The Diode Circuits-II Lecture No: 10 Contents: Ideal & Practical Diodes. Terminal Characteristics of Junction Diodes. DC Load Line and Quiescent Conditions. Piecewise Linear Model Small Signal Analysis of Diodes Dynamic Resistance, AC Resistance Capacitance and Switching Response, 3 References: Microelectronic Circuits: Adel S. Sedra and Kenneth C. Smith. Electronic Devices and Circuit Theory: Robert Boylestad & Louis Nashelsky ( Prentice Hall ). Introductory Electronic Devices and Circuits: Robert T. Paynter. Electronic Devices : Thomas L. Floyd ( Prentice Hall ). References (Figures): Chapter 2 Diodes: Figures are redrawn (with some modifications) from Introductory Electronic Devices and Circuits By Robert T. Paynter The Diode Models 1. The Ideal Diode Model 6 The Diode: p n Anode Cathode P-N Junction Diode Schematic Symbol: The left hand diagram shows the reverse biased junction. No current flows flows. The other diagram shows forward biased junction. A current flows. Diode Circuits: anode cathode Forward bias Reversed bias - - + + 7 8 Forward-Biased Diode Circuit: 9 Reverse-Biased Diode Circuit: 10 Effect of VF: Value Ideal Practical VF 0 V V VR1 5 V V I 5 mA mA 11 Example-1 12 Example-2 13 Example-3 14 Percentage Error: where X = the measured value X’ = the calculated value 15 Example-4 Power Dissipation PD(max) 16 17 I0 and PD(max) Relationship: where I0 = the limit on the average forward current PD(max) = the forward power dissipation rating of the diode VF = the diode forward voltage ( for Si) 18 Forward Power Dissipation PD(max): Choose a diode with forward power dissipation PD(max) at least 20% greater than actual power dissipation. 19 Example 5. A diode has a forward power dissipation rating of 500 mW. What is the maximum allowable value of forward current for the device? 20 . | Dr. Nasim Zafar Electronics 1 EEE 231 – BS Electrical Engineering Fall Semester – 2012 COMSATS Institute of Information Technology Virtual campus Islamabad The Diode Circuits-II Lecture No: 10 Contents: Ideal & Practical Diodes. Terminal Characteristics of Junction Diodes. DC Load Line and Quiescent Conditions. Piecewise Linear Model Small Signal Analysis of Diodes Dynamic Resistance, AC Resistance Capacitance and Switching Response, 3 References: Microelectronic Circuits: Adel S. Sedra and Kenneth C. Smith. Electronic Devices and Circuit Theory: Robert Boylestad & Louis Nashelsky ( Prentice Hall ). Introductory Electronic Devices and Circuits: Robert T. Paynter. Electronic Devices : Thomas L. Floyd ( Prentice Hall ). References (Figures): Chapter 2 Diodes: Figures are redrawn (with some modifications) from Introductory Electronic Devices and Circuits By Robert T. Paynter The Diode Models 1. The Ideal Diode Model 6 The Diode: p n Anode Cathode P-N Junction Diode Schematic Symbol:
