Untitled Quiz

Diode 2E6-B

• Non-linear circuit elements are introduced.
• Diodes are analyzed in circuits.
• Diodes are used in limiting, protecting, and half-wave rectifying circuits.
• The diode is the most fundamental non-linear circuit element.
• It is a two-terminal device.
• Circuit symbol: An arrow pointing from the p-type material to the n-type material, with a + and - sign to indicate the positive and negative terminals.
• Cathode (minus) at ground.
• Anode (positive) at voltage supply.
• A physical mark (thick black ring, shorter leg or kink) indicates the cathode.
• Ideal diode terminal characteristics:
  • Negative voltage: No current flows (open circuit).
  • Positive voltage: Full current flow (short circuit).
• Diode i-v characteristics -Reverse bias: No current flows (horizontal line at 0 on the graph). -Forward bias: Current flows (vertical line on the graph).
• Diodes are employed in many day-to-day electronic/electrical systems for rectifying, limiting, and circuit protection.
• Limiting (clamping): Limits voltage levels to predetermined values.
• Protector (clipper): Implement by using a diode and resistor in series.

Half-Wave Rectifier

• Uses a single diode in series with the AC source.
• During positive half-cycle: The diode acts as a closed switch.
• During negative half-cycle: The diode acts as an open switch.
• The rectified voltage is fed to a load resistance.
• The output signal has a single polarity.
• Half-cycle of the input-wave is retained, while the other is lost.
• Output voltage expression for negative input: Vs(t) < 0V→ the diode acts as an open circuit, ip(t) = 0A, Vo(t) = 0V,.
• Output voltage expression for positive input: Vs(t) ≥ 0V → the diode acts as a short circuit, ip(t) = Vs(t)/R1
• Equivalent DC voltage of the output signal: Vo,DC= Vo,max/π
• Average output power: Po = (Vo,max^2)/4
• Average input power: Ps = (Vs^2)/2

Analogue-to-Digital Conversion 2E6-B

• Introduction to the Analogue-to-Digital Converter (ADC).
• Introduction to the temporal sampling theorem.
• Analysis of example ADC circuits.
• Analogue signals can take on any value from a continuous range, while digital signals can take on only a finite number of values at discrete spaced time points, each represented by a digital code.
• The process involves sampling and then quantizing an analogue signal to convert it into digital form.
• Sampling in time: Examining the signal value at specific instances (indicated by short vertical lines).
• Quantization: Comparing sampled values to a set of levels and selecting the closest one. The sampling rate should be greater than or equal to twice the highest frequency component of the signal to avoid aliasing. A filter is often required.
• ADC block diagram: Analog input -> ADC converter -> digital output
• Flash ADC: Lightning-fast conversion speed, uses comparators to directly compare the input signal to a range of reference voltages.
• Resolution: The fineness of the quantization levels (related to the number of bits in the digital representation of the signal), typically expressed in volts.
• Example of the process.
• Non-ideal aspects of ADC.

Cascading 2E6-B

• Introduce the cascade of multiple op-amps.
• Analyze some circuits containing cascades
• System gain of K op-amps: Avs= A(1) × A®2 ... × AK

Practical Op-Amp Circuits

• Introduction to Inverting and Non-inverting op-amp operation.
• Step-wise approach to analyzing op-amp circuits.
• Analysis of some circuits containing op-amps.
• Practical op-amp circuits.

Voltage-Controlled Voltage Source 2E6-B

• To introduce the voltage-controlled voltage source.
• To establish real world limitations of the ideal op-amp conditions.
• To analyze some circuits containing voltage-controlled voltage sources.
• Real-world op-amps: Finite input and output resistance. Finite open-loop gain
• Ideal op-amp model including input/output resistances.
• Analysis and relations of unity gain buffer.
• Voltage gain, current gain, and power gain expressions.

Full-Wave Rectifier 2E6-B

• Introduction to filtering capacitor.
• Introduction to the full-wave rectifier.
• Analysis of the output function (root mean square voltages, average power, and power gain).
• Block Diagram of a power supply converting an alternating current(AC) to direct current (DC)
• Full Wave rectifier Circuit with Transformer
• Calculations of the power gain.
• Design considerations for smoothing the output, time constant (Tau)
• Ideal conditions for the full-wave rectifier.