Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [push-pull]

A circuit that uses a pair of active devices (such as complementary transistors) to alternately source current ("push") to or sink current ("pull") from a load.

A circuit that uses a pair of active devices (such as complementary transistors) to alternately source current ("push") to or sink current ("pull") from a load.

202 questions
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What is causing the distortion in the negative cycle of this push-pull speaker driver?

I'm trying to build a unity-gain push-pull output stage to drive a small ~8 Ω speaker (measured DC resistance is 7 Ω; I don't have a datasheet for it). This is for use with a single rail battery supply, so for the op-amp I've chosen an LM324. For…
mountainmad
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What does the 100 Ω resistor do in this push-pull amplifier?

The following circuit is from The Art of Electronics, 3rd edition: What I don't understand in the circuit is the role of the 100 Ω resistor. The authors say that it: ... serves to eliminate the “dead zone” as conduction passes from one transistor…
apadana
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What is the basic idea behind the so-called "diamond buffer"?

The idea for this question came about after I wrote an answer to a similar question. This "diamond solution" was something unknown to me. I took a look at Wikipedia page (see the picture below) and it immediately impressed me. (The picture is taken…
Circuit fantasist
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Difference between push-pull and totem-pole

I can't understand/see the difference between a push-pull and a totem-pole output. Push-pull: Totem-pole: Do these circuits have a transistor in the input for something like "double amplification?"
Martino Pistis
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Why would you enable pullup for a GPIO pin in push-pull mode?

In this STM32L486xx HAL User Manual (note: 36 MB!) is an example for GPIO configuration to power an external LED on page 53. The code lines that are confusing me are these two: GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; GPIO_InitStruct.Pull =…
jusaca
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What is a push-up/pull-up resistor?

A.S. The question A question on pull up resistors answers only a part of my question as already mentioned in "EDIT" made shortly after this question was asked & answers here (below) are much detailed, in-context & easy to understand. Definitely not…
RinkyPinku
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Unkown distortion in low power push-pull amplifier

I'm trying to make a small headphone amplifier, and I started out simple: I'm using a LM358 opamp to drive a push-pull stage with a pair of BD transistors. I started by trying a single channel (only one of the sides of the headphone) so I could…
user2934303
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Class AB crossover distortion diode fix

In the class AB amplifier shown below, we use diodes to make the PNP and NPN conduct equally. How do the diodes make them conduct equally? Is there some intuition I could use to understand this phenomenon?
lub2354
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What is the easiest way to reduce quiescent current in a AB power amp?

I'm trying to design an push-pull amplifier for a 4 ohm load, it works with a 48 V source. This is the latest design I did: (Input and output are in those two capacitors and the potentiometers are used to set the output DC point and the push-pull…
user2934303
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Push-pull power amplifier on complementary darlingtons

I decided to make a power DC-amplifier. I used complementary darlington pair TIP142 and TIP147. Also TL082 used for negative feedback. The schematic is as below: I gave 100 kHz sine signal and under oscilloscope I noticed the crossover distortion.…
Madras
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Op-amp based virtual ground with BJT buffer

I have a line-level audio circuit (2-channel balanced to unbalanced input circuit feeding a stereo volume control IC feeding a 2-channel unbalanced to balanced output circuit) which needs a dual PSU (±12V or ±15V). I have some trouble sourcing parts…
Dan Kadera
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Question about push-pull MOSFET driver

simulate this circuit – Schematic created using CircuitLab If I have an op-amp with feedback and enough voltage headroom, do I still need to add the biasing diodes (Q2, Q4)? In the above push-pull circuit, for a very brief moment when the signal…
ElectronSurf
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MHz gate switching: choosing BJTs

I'm trying to build a discrete driver to switch a power transistor (Qg=12nC, Vg=0->6V). I want to push the limits to see what is possible with discrete components (so no driver IC) so I'd like it to have a rise/fall time close to 20ns. This comes…
John HTS
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Designing a fast LED driver from scratch

I plan to build a LED driver that can pulse a high-power LED (3 W) down to the 100 s of nanoseconds pulse regime, yet also allows longer pulses (up to 100 ms) should be possible. The LED should be driven off a TTL/GPIO signal. I’m admittedly a…
JJCale
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use of diodes and resistors in a push-pull amplifier

I am a beginner in electronics facing a bit more difficult problem. what might be the function of the two resistors(R4,R5) and diodes(D1,D2)? in the circuit below?
Hilton Khadka
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