Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [matching]

Ensuring that two or more electrical components (transistors, resistors, etc.) have nearly equal characteristics (e.g. offset voltage, threshold voltage, resistance, etc.) for good performance when working together in a circuit.

Ensuring that two or more electrical components (transistors, resistors, etc.) have nearly equal characteristics (e.g. offset voltage, threshold voltage, resistance, etc.) for good performance when working together in a circuit.

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Can ULN2003 be a poor-man’s matched diode array?

I have a log/anti log application that requires “slightly” matched diodes - something better than you get just by grabbing a bunch of 1N4148s from a bin. I need the matching to be across each group of 3 diodes. The goal is to be cheap, the relative…
Kuba hasn't forgotten Monica
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Transmission Line: characteristic impedance matching

The textbook explains a situation in which when you have 2 unmatched transmission lines (different characteristic impedance), you can connect a new line in between such that the input impedance would match. Say I have a line #1 with characteristic…
randy
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Can I merge two impedance matching circuits?

I've got an RF transceiver (Nordic's nRF24L01+) which shows a typical circuit to match its antenna output to a single ended 50 ohm impedance. I've also got a chip antenna which comes with an example circuit to match a 50 ohm line to the antenna feed…
cksa361
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A poor man's alternative to a network analyzer for antenna matching

I'm doing a small board with a 915 MHz transceiver. A small helical antenna is used, which is located on board with a very short path (10 mm) from the IC, including balun and a matching network. There are no RF connectors or real state available to…
user44206
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question about transistor matching circuit

I'm studying this transistor matching circuit provided initially by Bob Moog. I think I mostly understand how it works, the op amp, bjt not under test and resistors form a current source, which stays constant for each transistor Vbe is measured for.…
mhz
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Custom USB Impedance question

I'm looking at making my own USB cable for a project. The primary issue I'm having is that I'm getting a lot of capacitance in my cable between D+ and D- (400ish pF) which is enough to throw off the signals being read by my pc. Is there an easy…
Shensmobile
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Antenna Matching Network

I am trying to match a gsm antena, doing it on a pcb, first time in practice. I understand the whole process to adapt it, I've done it in simulators. However, I don't understand the need for a pi matching network, since (theoretically) and LC…
Pedro Lopes
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Matching transistors for discrete op amp (audio use)

I am building some GAR2520 discrete op amps that require a matched pair of BC550(CTA) NPN transistors. I built a simple emitter follower with a 15 V supply, biased at about half that. I input a 1 kHz sine wave from a signal generator at 500 mV…
Dave Walwark
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Impedance matching an RLC circuit (inductor macroscopically drawn on PCB)

Context: I am a physics grad student with basic knowledge of circuits, but impedance matching and RF domain are beyond my normal scope. My PCB is actually copper bonded to a ceramic substrate that is going in my vacuum chamber, so knowing the…
Alejandra Collopy
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Impedance transformer, how to measure

I am preparing to do some RF mixer experiments with the SA612 Gilbert cell mixer. I started out with the impedance matching as I understand that the input and output need to be matched. From what I read, the impedance should match 1500 ohm single or…
Majodi Ploegmakers
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Should Ethernet MDI Pairs all be Length Matched (Inter-Pair) before going into magnetics?

I've been trying to find information for the above question and I can't seem to find anything. I have 1000 BASE-T lines coming from an Ethernet cable to a PCB mounted connector. I'm pretty much confined to the area shown below: The lines are not…
user3171804
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How do you find matched components?

I am designing a twin-T filter, which has a cut-off around 4.5 MHz. In this filter, both R1 and R2 must be 2 x R3. C1 and C2 must be half of C3. I have selected R1 = 10k and C1 = 3.6pF and that gives me a cut-off around 4.42 MHz. But I need to find…
Thomas O
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Matching the impedance of a filter?

Currently designing a circuit consisting of 50 Ohm rated ICs. Between two ICs (switches), I will place a BP-filter made out of discrete components (high-Q inductors and capacitors). The filter will probably be 7th order. My question: Is it…
paw
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Matching mosfets - linear servo amplifier (AB)

I'm replacing a bunch of burnt mosfets in a linear amplifier for a brushless motor. 3 phases Each phase: 3 pairs of totem IRFP240 / IRFP9240 in parallell. (no R in series) My main concern is matching the new triple-pairs. Which would be the most…
user247245
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What drives mechanical piezo device ultrasound maximum (sound) power output - electrical power or voltage?

Many definitions of piezo devices say that they convert mechanical energy to electrical (voltage) potential energy. This gives the impression that you want a high voltage to drop onto piezo device when driving it from an amplifier. How do I drive…
EMCInduction
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