The Hybrid Equivalent Model The following hybrid parameters are developed and

# The hybrid equivalent model the following hybrid

• 36

This preview shows page 9 - 21 out of 36 pages.

The Hybrid Equivalent Model The following hybrid parameters are developed and used for modeling the transistor. These parameters can be found on the specification sheet for a transistor. h i = input resistance h r = reverse transfer voltage ratio (V i /V o ) 0 h f = forward transfer current ratio (I o /I i ) h o = output conductance 8 Simplified General h-Parameter Model h i = input resistance h f = forward transfer current ratio (I o /I i ) 9 r e vs. h-Parameter Model ac fe e ie h r h Common-Emitter Common-Base 1 h r h fb e ib 10 The Hybrid Model The hybrid model can be approximated by the r e parameters. 11 Common-Emitter Fixed-Bias Configuration The input is applied to the base The output is from the collector High input impedance Low output impedance High voltage and current gain Phase shift between input and output is 180 12 Common-Emitter Fixed-Bias Configuration AC equivalent r e model 13 Common-Emitter Fixed-Bias Calculations C o 10R r e C v e o C i o v r R A r ) r || (R V V A e B C o r 10 R , 10R r i e B C o o B i o i A ) r )(R R (r r R I I A C i v i R Z A A Current gain from voltage gain: Input impedance: Output impedance: Voltage gain: Current gain: e E r 10 R e i e B i r Z r || R Z C o O R 10 r C o C o R Z r || R Z 14 Common-Emitter Voltage-Divider Bias r e model requires you to determine , r e , and r o . 15 Common-Emitter Voltage-Divider Bias Calculations Current gain from voltage gain: Input impedance: Output impedance: Voltage gain: Current gain: e i 2 1 r || R Z R || R R C o 10R r C o o C o R Z r || R Z C o 10R r e C i o v e o C i o v r R V V A r r || R V V A e C o C o r 10 R , 10R r i o i 10R r e i o i e C o o i o i I I A r R R I I A ) r R )( R (r r R I I A C i v i R Z A A 16 Common-Emitter Emitter-Bias Configuration 17 Impedance Calculations E b E e b E e b b B i R Z ) R (r Z 1)R ( r Z Z || R Z C o R Z Input impedance: Output impedance: 18 Gain Calculations Current gain from voltage gain: Voltage gain: Current gain: E b E e b R Z E C i o v ) R (r Z E e C i  #### You've reached the end of your free preview.

Want to read all 36 pages?

• Spring '17
• Alternating Current, Input impedance, Impedance matching, Electrical parameters, BJT Transistor Modeling

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern  