Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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).

0
votes
2answers
33 views

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 ...
0
votes
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
votes
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 ...
0
votes
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 ...
0
votes
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 ...
2
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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/ ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
4
votes
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 (...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
-2
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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. ...
1
vote
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....
0
votes
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)?
0
votes
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....
1
vote
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 ...
0
votes
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 ...
1
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 (...
1
vote
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 (...
1
vote
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, ...
0
votes
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. ...