analog electronics

test 1 (weeks 1 to 3)

what are the 2 types of electronic signals

analog and digital

what is an analog signal

Continuous range of amplitude over time.

what is a digital signal

Discrete voltage over time

what is an Analog to Digital Converter (ADC)

Convert analog signal to digital signal

what is a Digital to Analog Converter (DAC)

Convert digital signal to analog signal.

what is the input of electronic systems

Measurement of physical quantities

what is an electronic system

Consists of electronic devices and components. Process electronic signals, interface between the sensors on the input side and actuators on the output side.

what is an electronic systems output

Vary other physical quantities

what are signal amplification types

voltage amplifier, current amplifier, power amplifier

what is a voltage amplifier

Increase the voltage level of the signal • High input impedance, low output impedance

what is a current amplifier

Increase the current level of the signal. • Low input impedance, high output impedance.

what is a power amplifier

Increase the power of a signal.

what are the functional types of amplifiers

operational amplifier, differential amplifier, instrumental amplifier, radio frequency

what is an operational amplifier

High-gain differential amplifier with feedback

what is a differential amplifier

Amplify the different between two signals

what is an instrumental amplifier

A precise differential amplifier with high CMRR.

what is a radio frequency amplifier

Amplify a signal for use over RF range

what are interstage coupling types of amplifier

RC-coupled, LC-coupled< Transformer-coupled, Direct-coupled

what is an RC-coupled amplifier

use a network of resistors and capacitors to connect stages of amplifiers

what is an LC-coupled amplifier

use a network of inductors and capacitors to connect stages of amplifiers.

what is a transformer-coupled amplifier

use transformers to match impedances to the load side and input side.

what is a direct coupled amplifier

use no interstage elements; each stage is connected directly to the following and preceding amplifier stages.

what are the frequency type amplifiers

DC amplifier, AF amplifiers, video amplifiers, ultra-high frequency

what is a DC amplifier

amplify signals from 0 frequency (DC) and above

what is an AC amplifier

amply audio signal from 20 Hz to 20 kHz

what is a video amplifier (frequency amplifier)

amplify signals up to a few hundred MHz.

what is an Ultra-high-frequency amplifier

amplify signal up to a few GHz.

what are the types of load amplifiers

audio amplifier video amplifier, tuned amplifier

what is an audio amplifier

audio type of load

what is a video amplifier (load type)

video type of load.

what is a tuned amplifier

amplify a single RF or band of frequencies

what is the system level design process purpose

Engineering systems are becoming increasingly complex. Transforms specifications into circuits.

what is the engineering design process

1. System designed using block functional block diagrams. 2. Circuit design 3. Device design

characteristic of conductors

Low resistivity, used in interconnects, electrodes

characteristics of semiconductors

Tuneable conductivity, core of transistors, diodes, ICs

characteristics of insulators

High resistivity, used in gates, capacitors, isolation

characteristic of semiconductor diodes

• Two-terminals: Anode and Cathode • Low resistance in the forwarded direction • High resistance in the reverse direction • Function as a controlled switch.

characteristics of Bipolar Junction Transistors (BJT)

• Three-terminal: the emitter (E), the base (B), and the collector (C). • The arrowhead identifies the transistor as a npn or a pnp. • Operate as current-dependent devices. • Amplify of signals or switch.

Field-Effect Transistors (FET) characteristics

• Next generation of transistors • Three terminals: the drain (D), the gate (G), and the source (S). • Operate as a voltage-dependent device. →The drain (output) current depends on the input gate voltage

what are the other FETs technologies

• MESFET (Metal–Semiconductor FET): GaAs. • HFET: GaN or GaAs • IGFET, FinFET, DEFET,

characteristics of semi conductors

Conduct electricity more than insulators but less than conductors

what happens if semiconductors are faced with high temperature

becomes a conductors

what happens if semiconductors are faced with very low temperature

becomes an insulator

what material is the most common semiconductor material

silicon

what bonds dose silicon have

covalent

characteristics of covalent bonds

• Strong and stable • Hold two atoms together tightly. • Require high energy to break it down

what is the affect of higher temperature on covalent bonds

Higher temperature could break down the bonds  free some electrons  increase the conductivity.

what is the doping process

• Inject other elements to silicon structure

what dose the doping process result in

create more mobile charges in silicon.

what are the 2 types of doping

N-type, P-type

process of N-type doping

Inject small amount of another element whose atoms have one more valence electron,

result of N-type doping

Allow negative charged electrons moving around, conducts current

whats P-type doping

Inject small amount of another element whose atoms have one less valence electron

result of P-type doping

Allow positive charged “holes” moving around, conducts current

characterisitics of forward direction in a ideal diode

• Zero resistance • Zero voltage drop • Infinite forward current

characteristic of reverse bias in ideal diodes

infinite resistance, zero current

what are the types of methods to analyse practical diode circuits

• Graphical Method • Approximate Method • Interactive Method • Mathematical Method

benefits of graphical method

Help to understand the concept of Q-point and the mechanism of the diode circuit analysis.

disadvantages of graphical method

• Not convenient for analysis. • Rarely used

benefits of approximate method

• Adequate for many applications • Useful as a starting point for a circuit design.

disadvantages of approximate method

• Does not take the nonlinear characteristic into account. • Result in approximate solution.

what are the types of models for diode circuits

• constant-drop DC model, • piecewise linear DC model, • low-frequency AC model, • high-frequency AC model, or • SPICE diode model.

why do we model practical diodes

In practice, multiple diodes are used in a circuit therefore diode circuits become complex• Analysis by the graphical or iterative method becomes time-consuming and laborious. • To simplify the analysis and design, diodes can be modeled

what is the constant-drop DC model

The constant-drop DC model assumes that a conducting diode has a voltage drop 𝒗𝑫 that remains almost constant and is independent of the diode current,

what is the piecewise linear DC model

The diode characteristic can be represented approximately by a fixed voltage drop 𝑽𝑻𝑫 and a straight line. This model represents the diode characteristic approximately by two piecewise parts: a fixed part and a current-dependent part. A piecewise linear.

what is the Low-Frequency Small-Signal Model

The operating point, which consists of both a DC component and an AC signal, will vary with the magnitude of the AC signal.

What happens if the reverse voltage of a diode exceeds the breakdown voltage?

The diode operates in the breakdown region, where reverse current increases rapidly and diode voltage remains nearly constant.

How does a Zener diode behave in the forward direction?

Like a normal diode.

How does a Zener diode behave in reverse if v_d<V_z

It offers very high resistance, acting like a normal reverse-biased diode.

How is the reversed Zener characteristic approximated?

As a fixed voltage V_Z0 and an ideal diode in series with Zener resistance R_Z​, with v_D=V_Z0+R_Zi_Z

What is a Zener regulator?

A circuit where the Zener diode maintains constant voltage across terminals, used as a voltage reference diode (shunt regulator).

Is Zener voltage dependent on current?

No, V_Z is independent of reverse current i_D=−i_Z

What is line regulation?

The ability of the Zener regulator to maintain constant output despite changes in supply voltage.

What is load regulation?

The ability of the Zener regulator to maintain constant output despite changes in load current

What is the rule of thumb for selecting i_Z(min)

Choose i_Z(min) as 10% of the maximum current.

what is this formula used for

finding the Zener current lower bound

what is this formula used for

to find the zener current upper bound

how is the Zener diode modeled in limiters?

As a piecewise linear characteristic: forward direction V_D0+R_D​, reverse direction V_Z0+R_Z

What are typical values of R_Z and R_D?

Very small, typically ~20 Ω, often neglected in analysis.

How is a symmetrical limiter made?

By connecting two Zener diodes in series opposing each other.

How does an unsymmetrical limiter with a Zener diode work?

when V_s is greater than V_D0 the output is limited to V_D0. when V_S is less than -V_Z0 the output is limited to -V_Z0

How does junction temperature affect V_Z?

Zener voltage changes with temperature, ~2 mV/°C, opposite to forward-biased diode.

How can temperature effects be minimized?

Connect Zener diode in series with a forward-biased diode—their temperature coefficients cancel out.

What happens to small-signal Zener diodes under power?

Power is low (milliwatts), junction temperature stays safe.

how is temperature reduced in power diodes?

They are mounted on heat sinks to keep junction temperature below limits.

When must a diode be derated?

If ambient temperature is above specified value.

Can a diode handle more power if ambient temperature is lower?

Yes, it can handle higher power.

What does a diode rectifier do?

Converts AC voltage to unidirectional DC voltage (AC–DC converter).

What are the most common diode applications?

Rectifiers.

What are the two main classifications of rectifiers?

Single-phase rectifiers and three-phase rectifiers.

Why is a transformer used in rectifiers?

To step AC input voltage up/down to required DC output.

How many diodes are required for single phase full wave bridge rectifier

4 diodes

for Single-Phase Full-Wave Bridge Rectifier what is the power factor assuming no loss

PF=1.0

dose Single-Phase Full-Wave Bridge Rectifier provide electrical isolation

no

What do rectifier outputs consist of?

A DC component and harmonics (cosine terms).

What is the role of filters?

Smooth the output by reducing ripple, producing nearly pure DC.

What are the three types of filters?

L filters, C filters, LC filters.

What do L filters oppose?

Changes in output current.

Which applications are L-filters generally used for?

High-power DC supplies.

What do C filters oppose?

Changes in output voltage.