Questions tagged [class-d]
A class-D (amplifier) refers to an electronic amplifier that operates the output devices (usually MOSFETs) as binary switches (either ON or OFF).
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Class D amplifier - equation for peak current?
I'm trying to spec a power supply for a class D amplifier IC. I have figured out the maximum RMS current draw by taking the RMS power rating of the amp, increasing that to compensate for efficiency ...
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1answer
82 views
Not functioning Class-D Stereo Amplifier circuit
I am connecting a circuit for Texas Instruments TPA3125D2 Class-D Aplifier.
Datasheet here:
http://www.ti.com/lit/gpn/tpa3125d2
The circuit design is here:
The circuit that was tested is not on ...
2
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1answer
75 views
Output Filter Components Breaking Class D Amplifier Chip
Hi I am designing a class D amplifier PCB using the TPA3122D2 amplifier chip. I am planning to base my circuit on the schematic from the evaluation board:
I bought components of the same values given ...
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1answer
31 views
How to Choose Proper Components for Class D Amplifier Circuit
Hi I am designing a class B amplifier PCB using the TPA3122D2 amplifier chip. I am planning to base my circuit on the schematic from the evaluation board (see below).
I have tried building out this ...
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1answer
76 views
Why would this Class D Audio Amplifier have low current draw?
Disclaimer: Saying I have very little knowledge of electrical engineering theory is an overstatement. I very much appreciate your help and patience. I'm not finding any questions similar to mine, but ...
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0answers
55 views
Audio PWM over Radio [closed]
I'm working on a project in which I must send audio over RF such that remote speakers can pick up the signal around a house/apartment. The goal is to broadcast music from a single device somewhere in ...
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0answers
37 views
Three level PWM modulator circuit feedback simulation
I'm trying to design a three level PWM circuit with feedback and i'm struggling to understand the feedback aspect.
The design is based on this design by Texas instruments and modified to suit three ...
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1answer
153 views
How would a mains transformer react to unfiltered “Class D” PWM sinewave on its primary?
Somewhat related to this question: How do I apply PWM signal to the primary side of a transformer to get synthesized sine wave at the secondary side? - specifically "Choice 1":
However in my case I ...
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1answer
403 views
IR2110 driver output causing shoothrough despite deadtime
I'm having trouble with the ir2110 output. I'm working on a class d full bridge amplifier and I use 2 ir2110 to drive 4 irf540N mosfets. The switching frequency I use to generate the PWM is 240kHz and ...
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0answers
57 views
High frequency PWM methods
I have a few questions regarding generating PWM waveforms in audio and motor driving applications.
I want to mess around a bit more with switching, gate driving circuitry and motor control/ ...
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1answer
180 views
MOSFET driver circuit configuration for half bridge MOSFETs for power amplifier
I am making a class D audio amplifier and I am using a MOSFET driver to control two MOSFETs in a half bridge configuration as shown in the circuit below
When I connected the circuit without the ...
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1answer
78 views
PWM Comparator types for Class D
I've started simulating a Class D amp, but it seems the MAX999 (I saw recommended elsewhere on this site) isn't working. Could anyone point me in the direction of why? I swapped in an LM311 which ...
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1answer
180 views
How do you model differential inductor in LTspice?
I wonder how I can model a differential inductor in LTspice?
I've an inductor that has half the turns on one side and the other half on the other side.
It's intended to be used in a bridge tied ...
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1answer
65 views
Removing switching artifacts from commercial audio amplifier
I got an audio amplifier but I have problems with that.
How to remove switching noise(artifact) from the output of Behringer iNUKE NU1000 Power Amplifier ,Audio amplifier?
please find
I got from ...
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1answer
75 views
High Frequency Excitation on Class D Amplifier
I'm building a discretized class D audio amplifier that's running at 250kHz that's designed to run on a single ended 80V supply. I was seeing very high amplitude, high frequency excitations on the ...
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2answers
91 views
How can I see if my filterless class-D audio amplifier is clipping or not?
So I'm using MAX98357A, which is a filterless class D audio amplifier. I'm running it using Vcc = 5 V. Looking at the page 28 of the datasheet, I see the folliwing formula for output voltage:
Output (...
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1answer
187 views
Resistor values for class D amplifier
I haven't done a bad job for this amplifier circuit since I got it to work with 470K for RV and 10K for RG but what I'd like to do is create a better quality sound output. Maybe my 1/2 watt 8-ohm ...
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0answers
529 views
Unfiltered square-wave as feedback in class D amplifier
I found this little circuit that (ab)uses a TL494 SMPS PWM controller as PWM driver for a class D audio amplifier:
(Source article @ Geekcircuits.com )
It uses the unfiltered, but constant amplitude ...
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1answer
70 views
How to achieve digitally adjustable supply rail sover a wide range (low up to 300V)?
I need to be able to vary the supply rail over a wide range (low voltage up to 300V DC). Current consumption will be from 1 mA up to 40mA. The thing will be powered by AC mains 120V. I am wondering ...
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2answers
723 views
low pass filter class d amplifier
I am designing a Class D audio amplifier. Im using a 40Khz triangular wave to modulate my input audio signal of 1Khz. However when I designed my low pass filter(cut-off frequency=20Khz), I still get ...
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3answers
1k views
Using a NE555 for 12V boost to 24V to power an amplifier
I'm trying to draw a supply scheme for a class D integrated amplifier.
It requires 21V to 24V power supply and about 6/7A of current at 24V. The input is a car battery: 10V to 14.4V.
I found this ...
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0answers
67 views
Audio Amplifier
We are using WM8960 Audio CODEC which has internal Class D Amplifier with up to 1W output for speakers. I plan to provide external Class D amplifier as optional which boost up the output power to 2W ...
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1answer
2k views
Put a resistor in series between amp and speaker
I use a PAM8403 class-D amplifier module (~ 2$ on ebay), which is very good, and stereo.
The output volume is too loud. If I lower the amp's input volume (via software), then obvisouly the output ...
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0answers
92 views
Class - D Amplification Problem
I am trying to make some amplifier circuit like Class - D type. Below is the circuit;
Input is sinusoidal @2500Hz.
I couldn't make gate driver circuit. Thats why i use voltage dependent voltage ...
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0answers
450 views
Stereo to mono amp solution with mono bridge
I have these stereo amplifiers - Adafruit 20W and Sure Electronics 15W.
If I connect this passive stereo to mono bridge at its output, will it technically be a good solution? Will the amps work ...
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1answer
174 views
How can I avoid saturation in current source amplifier?
I'm designing a class d amplifier with current feedback as in figure below
with the following features:
Vbus=50V
Iout programmable from 100mA to 1A rms
Vout=35Vrms max
When the load overcomes the ...
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1answer
768 views
Calculation and measurement of input and output impedances of a Class-D amplifier
How would I calculate, from datasheet information or elsewhere, the input and output impedances of a Class D power amplifier, in general or for say a chip like the LM4670 or the TPA2000D1?
{Note that ...
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2answers
451 views
Can I use a Class D amplifier as a summing amplifier?
Context: I'm creating a mono, battery powered speaker. I'd like to sum the left and right channels of a stereo input signal into a mono output signal, which I feed into a Class-D Mono Audio Amplifier ...
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1answer
106 views
Audio AMP Datasheet help
Disclaimer: I know you aren't supposed to ask about specific IC's as it is not helpful to the community in general, but I am at my wit's end here so I will try to make this as relevant as possible.
...
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0answers
104 views
Calculating real part of a square wave
i'm trying to understand how Bruno putzey in
Globally Modulated Self-Oscillating Amplifier with Improved Linearity
in section 4.2 Analysis comes to the equation in presented in (2), see snapshot below....
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1answer
215 views
Can a MOSFET h-bridge class-D amplifier be used as a digital-to-analog converter?
They are used as de facto DACs for low power audio systems and in power inverters. But how common are they for high frequency D/A conversion(or broadband)?
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1answer
274 views
Using AND gate as a comparator
I amb trying to desing a very simple Gate Driver for a Class-D audio amplifier.
In order to introduce the Dead Time my first thought was to use a RC conected to a comparator as an imput of an AND gate....
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0answers
635 views
Input filter for class d amplifier
I have built a ~50W class d amplifier powered by a 12V SMPS. My problem is that the output of the SMPS has high frequency noise. I know that the noise is not audible but I would like to remove all of ...
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2answers
573 views
Using an audio amplifier with differential outputs with headphones
I'm planning to use TPA2012D2 (http://www.ti.com/lit/ds/symlink/tpa2012d2.pdf) audio amplifier from TI from my headphone audio project.
This amplifier has a differential outputs for left and right ...
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vote
0answers
311 views
Switching problems in class D amplifier
I'm building a class D amplifier with a dsPIC as PWM modulator.
The part of the schematic that I want to talk about is the interaction between the microcontroller output (pwm signal) and the gate of ...
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1answer
161 views
Calculation of Breakdown Voltage
How can we calculate the breakdown voltage of a BJT in ADS?
Is it Possible or not in ADS?
Problem:- I have a ADS BJT model. I am using that to generate high voltage output. For that i need to bias ...
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1answer
71 views
analog shut down whilst turning on an LED
I am a EE student from Denmark, in the middle of making a class D audio amplifier.
In this matter, I have stumpled across a needed circuitry. I need a way to shut off my gate driver (essentially the ...
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2answers
1k views
Using a LM311n in a class D amplifier as comparator
I'm making a class D amplifier as a school project, and we are currently at a stage where we simply need to add the comparator. But the comparator (LM311n) does not seem to run as intended.
My ...
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2answers
3k views
Am I using IR2104 correctly?
simulate this circuit – Schematic created using CircuitLab
I am using the following circuit with given component values.
I am not getting a proper level of output from Ho or Lo pin to drive the ...
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2answers
500 views
Class-D Amplifier working outside audio range frequencies?
I've been wondering what could possibly limit the use of class-D amplifier to audio range frequencies. When I look at some class-d amplifier specs, it seems that a lot of them can't reach great ...
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2answers
2k views
Trying to remove distortion of speakers seems impossible
I'm working in a project with the goal of make a portable bluetooth speakers without distortion.
When I try to turn up the volume, the speakers start to make a distorsion, like when rhe radio can't ...
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2answers
519 views
Circuit to put digital amplifier into standby when no audio is at inputs?
I am putting together a battery powered audio amplifier using the PAM8403 class D chip.
http://www.diodes.com/datasheets/PAM8403.pdf
It has an active low STANDBY pin which turns off the circuits ...
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1answer
182 views
Dual passive low-pass filter
I am building a class D amplifier and need to design passive low-pass filters for H-bridge with cut off frequencies at about 400 Hz. However, I am unsure about few things, this is the simplified ...
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1answer
112 views
Ballpark achievable switching frequency for 100mW D-class amplifier
The background for this question is a Master level university group project, we're designing a class D sigma delta modulated amplifier which is part of a MIDI synthesizer on a large FPGA.
We're ...
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2answers
1k views
Purpose of gate driver in Class D amplifier
Can somebody explain to me why we need MOSFET gate driver in class D amplifier like in the picture below(common class D schematics)?
What I don't understand is if we for example have 9V rails, then ...
3
votes
2answers
807 views
Class D amplifier woofer filter designs
I am working on a 140W class D amplifier for my subwoofer. I am familiar with its topology but have few questions.
The music source is a radio that ouputs 200mV peak-to-peak signal containing all ...
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1answer
450 views
Options for class D amp using Power over Ethernet
I'm putting together a design for a small amplifier that utilises power over Ethernet (PoE). The design specifications are:
10w to 30w (as long as >10w power isn't critical)
56v asymmetrical power (...
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1answer
1k views
Class D inductor current calculation
How do I calculate the required inductor current (RMS, saturation) for a class D amplifier?
Assuming the following configuration:
Speaker impedance (Z) = 4 ohms
Power output (P) = 400W
(...
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2answers
1k views
Class D amplifier output filter calculation
I want to build a simple amplifier with TI's TPA3116D2, which is "filterless" Class-D amplifier. This device can be run with a traditional LC filter at the output, or, if the speaker wires are short, ...
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1answer
1k views
Small but powerful speakers [closed]
Why are powerful speakers like above 20w or 80w not small? I have never seen enough in the market which are under 3 inch but of 80W. The opposite is also true, some big speakers are of low wattage. ...
