Tag Archives: Amplifier

Low Cost/Voltage 3W Class-D Stereo Audio Amplifier for Portable Gadgets

This low cost low voltage 3W class-D stereo amplifier is based on PAM8403 IC, The PAM8403 is a 3W, class-D audio amplifier. It offers low THD+N, allowing it to achieve high-quality sound reproduction. The new filter-less architecture allows the device to drive the speaker directly, requiring no low-pass output filters, thus saving system cost and PCB area. With the same numbers of external components, the efficiency of the PAM8403 is much better than that of Class-AB cousins. It can extend the battery life, which makes it well-suited for portable applications. Trimmer Potentiometer helps to adjust the volume control, CN1 provided to feed the audio signal, CN2 power supply, Mute and shutdown in, LS1 and LS2 to connect the speaker. Shutdown and Mute pin required high level signal input, and can be connect to VDD power pins for normal operation, can be connect to GND for shutdown or mute the audio. The amplifier works well with standard audio signal input.

Low Cost/Voltage 3W Class-D Stereo Audio Amplifier for Portable Gadgets – [Link]

Hi-Fi Stereo Headphone Amplifier using LME49600

This project is the ideal solution for high output, high performance high fidelity stereo head phone amplifier. The project consists of Op-Amp LME498720 and LME49600 as output driver. The LME49600 is able to drive 32Ω headphones to a dissipation of greater than 500mW at 0.00003% THD+N while operating on ±12V power supply voltages.  The LME49600 is a high performance, low distortion high fidelity 250mA audio buffer. The LME49600 is designed for a wide range of applications and is fully protected through internal current limit and thermal shutdown.

Hi-Fi Stereo Headphone Amplifier using LME49600 – [Link]

Design of a Korg Nutube Amplifier

Karlwoodward @ www.rs-online.com/designspark is in the process of designing a “guitar pedal” for amplification and distortion using the Korg Nutube we featured earlier. The Part 1 of a series of articles goes through the basic aspects of tubes and valves, the pros and cons on using a Nutube valve as well as discussing about low gain and high source impedance. In Part 2 of the series he goes deeper by building a working prototype and making some measurements.

Teardown of a TDA7375 audio amplifier IC

A teardown of a TDA7375 audio amplifier IC from Electronupdate:

The TDA7375 audio power amplifier.
Another example of a long-lived integrated circuit.  1st introduced in 1998… looks like it’s still being made.

Teardown of a TDA7375 audio amplifier IC – [Link]

Simple Pressure Sensor Amplifier & Over Pressure Switch

The pressure sensor amplifier built using LM358 op-amp and MPXM2051GS pressure sensor from NXP semiconductor.  The circuit provides 4V output for full scale pressure input 0-7.5PSI.  One op-amp is used as amplifier and 2nd op-amp is used as comparator to provide an output at set value that can be used as over pressure switch to control a pump or solenoid.  This is a low cost general-purpose circuit for those applications where +/-3% performance is acceptable. Multi turn potentiometers are provided for Offset, span adjust & over/under Pressure set point to control output devices like solid state relay, Pump, and solenoid.

Features

  • Supply 12V DC
  • Pressure Sensor range 0-7.5PSI
  • Output 0-4V (Approx.)
  • PR1 Multi-Turn Potentiometer Offset
  • PR2 Multi-Turn Potentiometer Span Set
  • PR3 Multi-Turn Potentiometer Comparator (Switch) output Set
  • D1 Power LED
  • CN1 4 Header Connector Outputs & Supply Input

Simple Pressure Sensor Amplifier & Over Pressure Switch – [Link]

Amplifier requires no dc bias

john guy @ edn.com writes:

Intrinsically capacitive transducers and other high-impedance signal sources usually require ac coupling and a buffer amplifier to condition the signal for further processing. Buffers take many forms, but most of them compromise signal quality through the use of external resistors that provide a dc path for the input bias current. Recent improvements in op-amp technology allow ac-coupled inputs without the need for bias resistors.

Amplifier requires no dc bias – [Link]

Redefining a new state-of-the-art in microampere current-sense amplifiers

Silicon Lab’s TS1100 and TS1101 current sense amplifier’s features discussed in this app note.

Sensing and controlling supply current flow are a fundamental requirement in most all electronic systems from battery-operated, portable equipment to mobile or fixed-platform power management and dc motor control. High-side current-sense amplifiers (or “CSAs”) are useful in these applications especially where power consumption is an important design parameter. New CSA developments offer even greater benefits in allowing engineers to save power without sacrificing performance.

Redefining a new state-of-the-art in microampere current-sense amplifiers – [Link]

LTC3623 – Switching regulator doubles as Class-D audio amplifier

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Clemens Valens @ elektormagazine.com discuss about LTC3623 switching regulator which can be used as Class-D Audio Amplifier.

Sure thing, Elektor has published several designs of adjustable power supplies based on switching regulators, so we know that doing this properly in a reproducible way and without making things overly complex requires some serious head scratching. The anxiety may be reduced vastly though by a new adjustable synchronous buck regulator which uses a single resistor to set its output voltage anywhere between 0 and 14.5 volts. Using the device is very simple; you can even use it as an audio amplifier.

LTC3623 – Switching regulator doubles as Class-D audio amplifier – [Link]

How to Build a Class-D Power Amp

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Cezar Chirila @ allaboutcircuits.com shows how to build a Class-D amplifier which has amazing efficiency.

What is a Class-D audio power amplifier? The answer could be just a sentence long: It is a switching amplifier. But in order to fully understand how one works, I need to teach you all its nooks and crannies.

How to Build a Class-D Power Amp – [Link]

Tutorial on High-Power Balanced & Doherty Microwave Amplifiers

Tutorial on High-Power Balanced & Doherty Microwave Amplifiers [Link]