solution2 - ECE 442 Spring 2009 HW#2 Solutions 1. Note that...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 442 Spring 2009 HW#2 Solutions 1. Note that in all four cases I diode = I resistor (since they are in series). a) Using the ideal diode model: Circuit a): assume diode is ON V = - 3 V, I = 3 - V 10 k = 0 . 6 mA check assumption: I > 0 OK Circuit b): assume diode is OFF I = 0 , V = 3 - I · 10 k = 3 V check assumption: V diode = V anode - V cathode = ( - 3) - V = - 6 V < 0 OK Circuit c): assume diode is ON V = 3 V, I = V - ( - 3) 10 k = 0 . 6 mA check assumption: I > 0 OK Circuit d): assume diode is OFF I = 0 , V = - 3 + I · 10 k = - 3 V check assumption: V diode = V anode - V cathode = V - (+3) = - 6 V < 0 OK b) Using the constant voltage-drop diode model (with V D = 0 . 7 V ): Circuit a): assume diode is ON V = ( - 3) + V D = - 2 . 3 V, I = 3 - V 10 k = 0 . 53 mA check assumption: I > 0 OK Circuit b): assume diode is OFF I = 0 , V = 3 - I · 10 k = 3 V check assumption: V diode = V anode - V cathode = ( - 3) - V = - 6 V < V D OK Circuit c): assume diode is ON V = (+3) - V D = 2 . 3 V, I = V - ( - 3) 10 k = 0 . 53 mA check assumption: I > 0 OK Circuit d): assume diode is OFF I = 0 , V = - 3 + I · 10 k = - 3 V check assumption: V diode = V anode - V cathode = V - (+3) = - 6 V < V D OK Comparing the answers in a) and b): For circuits in which diode is off, the answers are the same, since both models coincide for V diode < 0; For circuits in which diode is on, the voltages V differ only by the amount of voltage drop across the diode (here V D =0.7V), and currents differ by V D 10 k = 0 . 07 mA .
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/19/2009 for the course ECE 442 taught by Professor Schutt-aine during the Spring '08 term at University of Illinois at Urbana–Champaign.

Page1 / 5

solution2 - ECE 442 Spring 2009 HW#2 Solutions 1. Note that...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online