Transcript Zenor Diode Diode Applications ES230 Jack Ou The Design of a Cell Phone Charger Output of the transformer Still need to be filtered to get a.

Zenor Diode
Diode Applications
ES230
Jack Ou
The Design of a Cell Phone Charger
Output of the transformer
Still need to be filtered to
get a DC voltage
Short for Positive Voltages and
Open for Negative Voltages
Behavior of Ideal Diode
Ideal diode:
Vanode>Vcathode: Diode is on
Vanode<Vcathode: Diode is off
An ideal current experieincing Vanode=Vcathode, carries no current
I/V Characteristics
A short
An Open
A diode
Vanode>Vcathode: Diode is on
Vanode<Vcathode: Diode is off
An ideal current experieincing Vanode=Vcathode, carries no current
In practice, consider a slightly positive or negative voltage to
determine the response of a diode.
Example 1
Example 2: An OR Gate Realized By Diodes
In Class Exercise
Example 3
c03f09
A Simple Cell Phone Charger Circuit
(R1 is necessary)
Another Application:
Signal strength indicator
Rectifier Circuit as Signal
Strength Indicator
A Limiter Circuit
Question: How do you modify this circuit so that it passes only
Different Models of a Diode
Choosing a Diode Model
Use the ideal model to develop a quick, rough understanding of a circuit.
If the ideal model is not adequate, uses the constant voltage model, which is
sufficient for most cases.
Occasionally, we will use the exponential model
Ideal Model versus Constant-Voltage Model
Express ID1 and ID2 as a function of IS1, IS2 and Iin.