Audio

MEMS Microphones is setting a new performance benchmark across a growing number of industries. These innovative silicon microphones were designed to extend the benefits of the lowest possible self-noise (high SNR) and lowest distortion to an ever-expanding number of applications. The project presented here is a low noise analog MEMS microphone Preamplifier with compression and noise gating. The project provides a studio-quality audio experience. The project is built using SSM2167 chip and InvenSense ICS-40180 Low-Noise Microphone with bottom port and analog output.

This is a compact size, mono, switch-mode (Class-D) audio power amplifier intended for multimedia and general-purpose high-power applications. It has greater than 87% efficiency and is capable of delivering 2W maximum continuous power to a 4Ω load. The project is designed to be driven by the line-out or headphone jack of a CD/MP3 player or to be directly connected to any audio source. The project includes header connectors for speakers, power supply, and audio input for quick connection. The project also has 3x jumpers for frequency selection and shutdown action. The project is built using the MAX4295 chip.

This is an AB class audio amplifier based on the TDA7388 chip and it is a great choice for car audio applications. This compact board has 4 channels each 26W with 4 ohms speaker. Then IC consists of a fully complementary PNP/NPN configuration and the TDA7388 allows a rail-to-rail output voltage swing with no need for bootstrap capacitors. The extremely reduced boundary components count allows very compact sets. The TDA7388’s inputs are ground-compatible and can stand very high input signals (±8 Vpk) without any performance degradation. The standard value for the input capacitors (0.1 µF) is adopted, and the low-frequency cut-off amount to 16 Hz. 4 x 3.5 mm stereo EP socket helps to feed audio signals, and the onboard screw terminal makes life easy for speaker connections, and the power supply input. Onboard jumpers are provided to select the standby and mute function. D1 indicates power present. Mounting a proper heatsink is very important for chip health.

This is a headphone amplifier project for audio digital-to-analog converters (DACs) with differential voltage outputs. This circuit converts the differential voltage output of the DAC to a single-ended, ground-referenced signal and provides the additional current necessary for low-impedance headphones. Project is built using OPA1688 low distortion, high-drive Sound Plus audio amplifier. The circuit tested with dual +/-5V DC supply, and it can drive a load 16 Ohms to 600 Ohms. Headphone amplifier provides an output 50mW into 32 Ohms. Signal for the right channel and left channel input is applied to the amplifier through connectors CN1and CN3, respectively.

This is an “Audio VU Meter” or “Sound Level Meter”, it is a general-purpose bar-graph Audio VU meter designed for fun projects. All you need is to hook up one wire to the output of the audio amplifier’s speaker pin along with GND and see the magic. The response of the circuit is very fast and it provides beautiful visual representation from audio input signal.

The Stereo Audio Amplifier project shown here is capable of delivering 2.5W per channel of continuous average output power to 4Ω loads using a single 12V supply at 10% THD+N. The project is built using the LM4752 chip. This chip is specifically designed for single supply operations and low external components count. The gain and bias resistors are integrated on-chip, resulting in a 2.5W stereo amplifier in a compact 7-pin TO263 SMD package. High output power levels at 12V supplies and low external component count offer high value for compact stereo and TV applications. Sufficient power dissipation is provided on PCB so no external heatsink is required for IC.

The 60 W Class-AB Audio Amplifier is a single-channel power amplifier board built around the STMicroelectronics TDA7296. This Class-AB amplifier is suited to a wide range of applications, including home stereo systems, self-powered speakers, and high-end televisions.

This simple project is an audio limiter based on the NJM2761 chip. It provides effective protection for speakers by limiting the audio signal level. The limit level is adjustable through an external trimmer potentiometer (PR1).

This Audio Processor designed using TDA7440 chip from ST. The chip is a volume tone (bass and treble) balance (Left/Right) processor for quality audio applications in Hi-Fi systems. A selectable input gain is provided. Control of all the functions is accomplished by serial bus I2C. The AC signal setting can be altered by resistor networks and switches combined with operational amplifiers.

The stereo audio amplifier project shown here is capable of delivering typically 40W per channel continuous average output power into an 8Ω load with less than 0.1% (THD+N). The project is built using an LM4766 chip from Texas Instruments, The performance of the LM4766, utilizing its Self-Peak Instantaneous Temperature (°Ke) (Spike) Protection Circuitry, places it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). Spike Protection means that these parts are safeguarded at the output against overvoltage, undervoltage, overloads, including thermal runaway and instantaneous temperature peaks. Each amplifier within the LM4766 has an independent smooth transition fade-in/out mute that minimizes output pops. The IC’s extremely low noise floor at 2µV and its extremely low THD+N value of 0.06% at the rated power make the LM4766 optimum for high-end stereo TVs or mini-component systems.

The product described here is a high-efficiency dual BTL class-D audio amplifier with single supply operations. The project was built using TDA7491LP13TR from ST. The low profile PCB design can fit in a small area, operating power supply 9-12V DC, Project supports single-ended or differential audio signal inputs. Jumpers are provided to set the various gains, standby, and mute functions.