Fundamentals of Electronics: Diodes

What does 𝑟𝑎𝑣 represent in the context of average AC resistance?

What does the piecewise-linear equivalent circuit of a diode primarily focus on?

What happens to 𝑟𝑎𝑣 in the simplified equivalent circuit for most applications?

What role does the battery 𝑉𝐾 play in the piecewise-linear equivalent circuit?

What can be implied by removing 𝑟𝑎𝑣 from the ideal equivalent circuit?

What is the average voltage across a Ge diode at a current of 1 mA?

At a current of 30 mA, what is the voltage across the Si diode?

Which type of resistance is characterized by a stable operating point when a DC voltage is applied to a diode?

How is the dynamic resistance of a diode generally defined under sinusoidal voltage conditions?

What is the average value of the voltage across a GaAs diode at a current of 4 mA?

What does the average AC resistance reflect in a diode's operation?

In the comparison of Ge, Si, and GaAs diodes, which diode exhibits the highest voltage at a current of 30 mA?

Which diode has an average voltage value closest to its knee voltage at 1 mA?

Fundamentals of Electronics

The presentation covers the fundamentals of electronics, specifically diode characteristics and circuits.
It introduces Shockley's equation, which defines the general characteristics of semiconductor diodes.
The equation is: ID = Is(eVD/nVT – 1)
Variables include: ID (diode current), Is (reverse saturation current), VD (forward bias voltage), n (ideality factor), VT (thermal voltage).
The thermal voltage VT is calculated as VT = KT / q
Boltzmann's constant (k) = 1.38 × 10⁻²³ J/K
Absolute temperature (TK) is calculated as 273 + °C
Magnitude of electronic charge (q) = 1.6 × 10⁻¹⁹ C

Diode Characteristics and Circuits

Diode characteristics are defined by Shockley's equation.
The ideality factor (n) typically ranges from 1 to 2, with 1 being a common assumption.
Diode current changes based on the applied voltage (forward or reverse bias).
For positive VD values, ID = Is e^(VD/nVT)
For negative VD values, ID = -Is

Resistance Levels

Diode resistance changes as the operating point moves between regions.
There are three types of resistance: DC or Static Resistance, AC or Dynamic Resistance, and Average AC Resistance.

Diode Equivalent Circuits

Equivalent circuits represent the diode's terminal characteristics.
Three types of equivalent circuits are included:
- Piecewise-linear Equivalent Circuit
- Simplified Equivalent Circuit
- Ideal Equivalent Circuit
The Piecewise-linear circuit approximates the diode's characteristics using straight-line segments.
The Simplified circuit removes the average resistance and considers only the diode's voltage drop.
The Ideal circuit only allows current in one direction. The voltage drop is zero in the forward direction and infinite in the reverse direction.
The presentation also includes practical examples demonstrating how to calculate current and voltage using each model.

This quiz explores the fundamentals of electronics focusing on diode characteristics, including Shockley's equation and the factors involved in diode behavior. Understand the parameters such as diode current, saturation current, and thermal voltage essential for analyzing diode circuits.