Products

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.

This is a 2V_rms Pop-Free stereo line driver with a stereo headphone driver designed to allow the removal of the output DC-blocking capacitors for reduced component count and cost. The project is based on the DRV604 chip which is ideal for single supply electronics where size and cost are critical design parameters. The project is capable of driving 2V_rms into a 5kΩ load and a clean 40mW into a 32Ω headphone with a single 3.3V supply voltage. Line and headphone outputs have ±8kV IEC ESD protection. The device has built-in shutdown control for pop-free on/off control. The DRV604 does not require a power supply greater than 3.3V to generate its 5.6V_pp output, nor does it require a split rail power supply. The DRV604 integrates its charge pump to generate a negative supply rail that provides a clean, pop-free ground biased 2V_rms output. This project is configured with single-ended header input connectors for analog input, headphones, and line output. The power supply is connected via a four-pin 2.54mm pin header.

This is a breakout board for the IC  PCM1795  stereo digital-to-analog converter (DAC), The  DAC  module accepts pulse code modulation  (PCM)  and direct stream digital  (DSD)  audio data formats, thus providing an easy interface to audio digital signal processors (DSPs) and decoder chips which will convert digital signal into analog signal. Sampling rates up to  200 kHz  are supported. A full set of user-programmable functions is accessible through an  SPI  or  I2C  serial control port that supports register write and readback functions. The  PCM1795  device supports the time-division-multiplexed  (TDM)  command and audio  (TDMCA)  data format.

This compact preamplifier module is designed to amplify small signals from high-source-impedance sensors with minimal added noise. It delivers a midband gain of 60 dB and a flat frequency response from approximately 16 Hz to 43 kHz. The clean roll-off at the corner frequencies produces a natural-sounding filter response well suited to audio applications.

This compact preamplifier module is designed to amplify small signals from high-source-impedance sensors with minimal added noise. It delivers a midband gain of 60 dB and a flat frequency response from approximately 16 Hz to 43 kHz. The clean roll-off at the corner frequencies produces a natural-sounding filter response well suited to audio applications.

This  is a Voltage Controlled Amplifier (VCA). A VCA board helps users control the Audio Level from a remote potentiometer. It requires a single-ended audio signal in the input. Gain control voltage can be adjusted through an on-board potentiometer or use an external potentiometer connected to CN4. The project works with a dual ±15V power supply. Screw terminal connectors are provided for signal input and signal output. The project is built using THAT2181LA chip, a VCA that is designed for high-performance audio-frequency applications requiring exponential gain control, low distortion, wide dynamic range, and low control-voltage feedthrough. These parts control gain by converting an input current signal to a bipolar logged voltage, adding a DC control voltage, and re-converting the summed voltage back to a current through a bipolar antilog circuit. Stereo control of VCA with a single potentiometer is possible.

This board is an Audio Processor built using  PT2033  chip audio processor designed for versatile applications. It includes 3 stereo input selectors with internal gain and master volume control with low-frequency loudness compensation. It is capable of individual channel output volume adjustment and also tone control.

The circuit shown here is a complete microphone signal conditioning system based on a single SSM2166 integrated circuit. Designed primarily for voiceband applications, this integrated circuit provides amplification, RMS detection, limiting, variable compression, and downward expansion. An integral voltage-controlled amplifier (VCA) provides up to 60dB of gain in the signal path with approximately 30kHz bandwidth. Additional gain is provided by an input buffer OPAMP circuit that can be set anywhere from 0 dB to 20 dB, for a total signal path gain of up to 80 dB. The project operates on a single +5 V supply, accepts input signals up to 1V_rms, and produces output signal levels > 1 V_rms (3V_p-p) into loads > 5 kΩ. The internal RMS detector has a time constant set by an external capacitor. The SSM2166 contains an input buffer and automatic gain control (AGC) circuit for audio and voiceband signals. Circuit operation is optimized by providing a user-adjustable time constant and compression ratio. A downward expansion (noise gating) feature eliminates circuit noise in the absence of an input signal. Onboard trimmer potentiometer allows the user to set the downward expansion threshold, the limiting threshold (rotation point), input buffer fixed gain, and the internal VCA’s nominal gain at the rotation point.