Which feedback is used in source followers to reduce output resistance?
The feedback is, therefore, parallel-derived, series-applied, so it reduces output resistance and increases input resistance.
Which of the following configuration have low output resistance?
Detailed Solution
| Transistor Configuration | Common Base | Common Collector |
|---|---|---|
| Power Gain | Low | Medium |
| Input/Output Phase relation | 0° | 0° |
| Input Resistance | Low | High (750 kΩ ) |
| Output Resistance | High | Low (50 Ω ) |
What is resistive noise source?
Resistor noise is often specified as microvolts noise per volt of applied voltage, for a 1 MHz bandwidth. Thermal noise is the predominant source of noise for resistors.
Do resistors cause noise?
Resistors are inherently noisy, some less than others. All resistors produce some level of thermal noise. Akin to noise caused by the friction of water running through a pipe, the thermal noise comes from electron holes moving around in a conductor.
What is low output impedance?
Low output impedance is desired to suck the maximum current from the circuit. High impedance means the circuit draws or gives little power to the signal. low impedance means the circuit draws or gives more power to the signal.
What is the effect of negative feedback on noise?
Negative feedback reduces gain of the amplifier. It also reduce distortion, noise and instability. This feedback increases bandwidth and improves input and output impedances. Due to these advantages, the negative feedback is frequently used in amplifiers.
In which configuration the input resistance is lowest and output resistance is highest?
Detailed Solution
| Characteristics | CB configuration | CC configuration |
|---|---|---|
| Input resistance | Very low (40 Ω) | Very high (750 kΩ) |
| Output resistance | Very high (1 MΩ) | Low (50 Ω) |
| Current Gain | Less than unity | High (100) |
| Voltage Gain | Large | Low |
How do resistors reduce noise?
We can reduce the noise by reducing the resistance (this may increase current and/or power consumption), but reducing the temperature is not usually practicable (if we cool a resistor from room temperature (298K) to liquid nitrogen temperature (77K), its noise voltage is still more than half its room temperature value) …
How can you reduce noise in a circuit?
Below are 8 of the best ways to deal with electrical noise.
- Shield Your Cables.
- Use Twisted Pair Cables.
- Isolate Signals.
- Use Differential Measurements.
- Ground Wires Properly.
- Route Wires Strategically.
- Use Anti-Aliasing Filters.
- Consider Your Application.
Is low output impedance good?
Low impedance in a voltage source is usually preferred because it helps to keep out the noise out of the circuit and maintain a stable output voltage. A typical power supply acts as an ideal power supply with a series resistor connected in series with its output.