Questions tagged [input-impedance]
The input-impedance tag has no usage guidance.
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Derivation of the AC small-signal circuit and the canonical form of a DC-DC buck converter
I'm new to this forum and hope you can help me. I am in the process of designing an input filter for a DC-DC step-down converter 12V-5V/1A (Pic.1).
I am trying to determine the transfer function and ...
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Why does the author assume \$R_{in} = 1/ g_m \$ for this this circuit?
The following circuit is from Chapter 13 of Analog Design Essentials, page 1324, written by Willy Sansen.
Calculate \$R_{in}\$ for this circuit.
The author thinks \$R_{in} = 1 / g_m\$
However,
$$
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Load pull testing transceiver LNA input, impedance tuner DIY alternative
Transceiver vendors not always provide best components for input impedance matching in all variety of frequencies range that transceiver itself support, often provide impedance matching network ...
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Connecting an op-amp to a second-stage amplifier: loading effect considerations
I designed an amplifier with an OPA838 as follows:
First scenario: I want to connect the OPA838 to a next stage voltage LNA (Low Noise Amplifier).
What components or circuit should I add to my output ...
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Watching an open-collector input without disturbing it
I'm trying to control an opto-isolator (actually a photorelay such as a TLP354x but it doesn't really matter here).
The problem lie in an external device (black magic box) which is also controlled by ...
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The effect of input and output impedance
This picture shows the classical feedback system and this assumption about this system.
"the input impedances of both the amplifier and the feedback network are
infinite and their output ...
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LM3900: different input impedances in symmetric pins?
Referring to the LM3900 "Quadruple Norton Operational Amplifiers" datasheet, consider the schematic of each single amplifier at page 1.
simulate this circuit – Schematic created using ...
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May I safely apply negative voltage to PIC's analog input?
For example I'd like to apply AC voltage ~3V. Could I not detect, but simply connect to MCU? I'd measure positive side as regular ADC, but I simply do not want negative side of amplitude to damage it. ...
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How can we calculate complex impedance when there is capacitor in the transistor circuit?
The following is from the book book Design of Analog CMOS Integrated Circuit, Page 187.
With the aid of Miller’s approximation, we have from Figure
$$Z_{in} = \frac{1} {\Biggr[C_{GS} + (1 + g_m R_D) ...
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Calculate the input resistance of the circuit with Miller's Theorem
The following is from the book Design of Analog CMOS Integrated Circuit, Page 176.
Calculate the input resistance of the circuit with Miller's Theorem.
In order to calculate the gain.
The current \$...
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Oscilloscope input clippers
The analog front end of an oscilloscope begins with an attenuation stage. Mostly they use two attenuation stages, like 1/1 and 1/50.
From: Rigol Homebrew Wiki - schematics page
The image above ...
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Why is the standard procedure for obtaining an equivalent circuit for bilateral amplifiers valid?
(Note that this question is related to this one, though this question represents my having somewhat better understood the "modification" alluded to in the linked question and wanting to ...
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Differential input impedance derivation
I have been looking into differential amplifier circuits, differential input impedance, and common-mode input impedance.
Everywhere I go (such as here or here), I see this as the solution for ...
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Input/output resistance for an accelerometer/Wheatstone bridge
I am looking at the MS 3028 Piezoresistive Accelerometer.
This is the internal schematic of the component, as a Wheatstone bridge, which per my understanding means it's a quarter bridge with other ...
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Output-Z (electret) higher than Input-Z (preamp)
What happens if an electret microphone capsule (JFET in catridge) is connected to a preamp with considerably lower input impedance than the capsule's output impedance itself?
ECM output Z: 2.2K
Preamp ...
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