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Feedback. Feedback Concepts. Expresion General de Circuitos Retroalimentados . Efectos de la Retroalimentación Negativa. Bandwidth with Feedback. Effect of feedback on (a) the pole location and (b) the frequency response of an amplifier having a single-pole open-loop response.
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Bandwidth with Feedback Effect of feedback on (a) the pole location and (b) the frequency response of an amplifier having a single-pole open-loop response.
Gain Stability with Feedback Gain calculations with feedback are often based on external resistive elements in the circuit. By removing gain calculations away from internal variations of and gm, the gain becomes more stable.
Amplifier Types • Voltaje Amplifier • Current Amplifier • Transconductance Amplifier • Transresistance Amplifier
Característica del Puerto de un Amplificador (Variable Voltaje)
Característica del Puerto de un Amplificador (Variable Corriente)
Feedback Connection Types 1. Voltaje Amplifier(series–shunt) voltage-mixing voltage-sampling topology. 2.Current Amplifier(shunt–series) current-mixing current-sampling topology 3.Transconductance Amplifier(series–series) voltage-mixing current-sampling topology 4. Transresistance Amplifier(shunt–shunt) current-mixing voltage-sampling topology
The Four Basic Feedback Topologies • Voltage-mixing voltage-sampling (series–shunt) topology. • Current-mixing current-sampling (shunt–series) topology. • Voltage-mixing current-sampling (series–series) topology. • Current-mixing voltage-sampling (shunt–shunt) topology.
Series-Shunt Feedback Voltaje Amplifier (b) Equivalent Circuit. (a) Ideal Structure
1. Series-Shunt Feedback Voltaje Amplifier Measuring the Output Resistance of the Series-Shunt Feedback Amplifier Rof : Vt/I.
1. Series-Shunt Feedback Voltaje Amplifier Derivation of the A circuit and b circuit for the series–shunt feedback amplifier. (a) Block diagram of a practical series–shunt feedback amplifier. (b) The circuit in (a) with the feedback network represented by its h parameters.
Summary of the rules for finding the A circuit and b for the voltage-mixing voltage-sampling case • Series-Shunt Feedback (Voltaje amplifier)
Example 1 Series-Shunt Feedback -Voltaje Amplifier
Example 1 Series-Shunt Feedback -Voltaje Amplifier
2. Series-Series FeedbackTransconductanceAmplifier (a) Ideal Structure (b) Equivalent Circuit.
2. Series-Series Feedback Transconductance Amplifier Measuring the Output Resistance of the Series-Series Feedback Amplifier Rof : Vt/I.
2. Series-Series Feedback Transconductance Amplifier Derivation of the A circuit and b circuit for the series–series feedback amplifier. (a) Block diagram of a practical series–series feedback amplifier. (b) The circuit in (a) with the feedback network represented by its h parameters.
2. Series-Series Feedback transconductance Amplifier Summary of the rules for finding the A circuit and b for the voltage-mixing current-sampling (series–series) case
Example 2Series-Series Feedback Transconductance Amplifier Some of the output current is directed back in series with the input. Example using a BJT: Feedback gain (Af):
3. Shunt-Shunt Feedback Transresistance Amplifier Ideal Structure
3. Shunt-Shunt Feedback Transresistance Amplifier Block diagram for a practical shunt–shunt feedback amplifier.
3. Shunt-Shunt Feedback Transresistance Amplifier Summary of the rules for finding the A circuit and b for the current-mixing voltage-sampling (Shunt-Shunt) case.
Example 2Shunt-Shunt Feedback Transresistance Amplifier The output voltage is fed back in parallel with the input. Example of an op-Amp circuit: Feedback gain (Af):
4. Shunt-Series Feedback Current Amplifier Ideal Structure
4. Shunt-Series Feedback Current Amplifier Block diagram for a practical shunt–shunt feedback amplifier.
4. Shunt-Series Feedback Current Amplifier Summary of the rules for finding the A circuit and b for the current-mixing current-sampling (shunt–series) case.
A. Voltage A. Transconductance A. Transresistance A. Current Summary of Each Type of Feedback and the Effects on Impedance
A. Voltage A. Transconductance A. Transresistance A. Current Summary of Each Type of Feedback and the Effects on Gain