Why isn't feedforward+feedback higher performance than just feedback?
This questions related to feedforward (FF) and feedback (FB) interactions.As an example, say there's a control system keeping a car centered in a lane while driving. Say the car includes a FF sensor...
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The functionality of a driver circuit
I was requested to make a laser driver circuit for a course project. After some research, I found this circuit.Can someone explain how this circuit works? What is 1R (R5&R6)? Can it be replaced...
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Phase shift near saturation mitigation in input stage amplifier -- How does...
I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer.Apologies for the quality... this is the best scan I could find. The design is furnished with the...
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Why won't my voltage feedback system work?
Vin is a constant DC source. This circuit will take a random DC input between 12.6V and 48V, and then maintain a constant output voltage of 5V using a system of voltage feedback.with the source...
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Why does 'Rfb' affect input impedance?
I am reading "Experimental Methods in RF Design" by Hayward, Campbell, and Larkin published by the ARRL. On the topic of feedback, see that two methods are presented.One method is emitter degeneration....
View ArticleWhat is the effect of tachometer feedback (derivative feedback) on the time...
I was going through some practice problems on Control System Modelling and came across this problem. It seems like the answer to this question is that the time constant is "reduced" but the result that...
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Negative phase margin and misconception of the point of instability in...
PreludeConsider a canonical block diagram of a negative feedback loop with gain \$K\$, plant transfer function \$G(s)\$ and feedback transfer function \$H(s)\$: -Regardless of what functions K, G, and...
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Designing a temperature feedback loop in Proteus
I am writing a term paper on the topic "Modeling of an Artificial Blood Circulation Apparatus". The task is to design a control unit based on the ATmega128 microcontroller in Proteus software. It was...
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Calculate input impedance of Common-gate circuit with feedback
The following is from the book book Design of Analog CMOS Integrated Circuit, Page 278.calculation of input resistance.The book said$$V_{out} = (g_{m1} + g_{mb1}) V_x R_D$$However, according to KCL.$$-...
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Avoiding overshoot in step response for robustness
In Systematic Design of Analog CMOS Circuits (Jespsers, Murmann) page 343, the following is stated in the context of where to place the non-dominant pole in a second-order loop transfer function of a...
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Is feedback positive or negative for this closed-loop circuit?
The following is from the book Design of Analog CMOS Integrated Circuit, Page 307.I think feedback is negative in my opinion.Here is what I think, see picture below.
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Why can't an ideal double integrator oscillate at the frequency below the...
The last paragraph of Example 8.6 in the second edition of Razavi's RF Electronics mentions a unit negative feedback closed-loop system composed of two ideal integrators. When the frequency is below...
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Changing output voltage of a buck converter by electronically swapping the...
I am going to design a circuit which is going to output some digital signals. The output stage of the circuit will have some level shifters. The level shifters will give flexibility to the user to...
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OpAmp resistor to ground in feedback loop
I am currently tasked with improving the design of an electrometer unit. It was NOT designed by an electrical, and there are some questionable design practices. My question is concerning the first...
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Contradiction between two circuit simulators in measuring open loop gain
I am implementing what I've learned over the past couple of days. This relates mainly to the simulation of a voltage regulator.I built the (roughly) same circuit in both TINA TI and LTspice to...
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Why am I concluding that the emitter-degenerated CE stage is unilateral?
Consider the attached small-signal diagram for an emitter-degenerated CE stage:It's been a long day so I must be making an error, but I continue to conclude that this two-port is unilateral (defined as...
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What is the definition of "the loading of feedback network on the...
There is the following example:simulate this circuit– Schematic created using CircuitLabIts loading of the feedback network on the input side is 40kohm in series. Its loading of feedback network on the...
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UC3842 optocoupler feedback confusion
I am having a slight confusion regarding the selection compensation pin of the UC3842 IC and the current mode control system given in the datasheet.Why is there an RC combination at the feedback of the...
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MP28167-A DC-DC converter recommends a resistor T-network in feedback loop
I am designing a DC-DC buck-boost converter using the MP28167-A, and the datasheet contains this section:I understand the need for a resistor divider such that the closed-loop control regulates the...
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Making block diagram of an op-amp configuration
Hi everyone,I have to make the block diagram of the above configuration. Supposing the input capacitance of op-amp Cin, I've drawn this:A is the open loop transfer function of the OPA.B is the voltage...
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