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Application Notes

AN-1283: Receiving the 4:2:0 Stream with the ADV7619

This 2-page Application Note outlines the usage of the ADV7619 HDMI® video receiver for the 4:2:0 HDMI stream 4k × 2k at 60 Hz. The ADV7619 can receive 4:2:0 video streams in the same way it receives 4:4:4 data in 4k × 2k modes. To enable this, set OP_FORMAT_SEL to the value of 0x54 and set all other I2C writes in the same way as for 4k × 2k 4:4:4 video mode. Because the ADV7619 works only as a bypass for 4k × 2k modes, it outputs samples as they are received without providing color space conversion (CSC). The receiver bypasses CP core and thus neither CSC nor up-conversion/down-conversion of video standard is available.

AN-1277: Utilizing the Cyclic Redundancy Check Block of the ADV7850

The ADV7850, the first complete audio/video front-end device developed by Analog Devices, targets the professional and consumer video markets. The device incorporates a frame checker block that employs cyclic redundancy checking (CRC). This 3-page Application Note outlines the background of the frame checker function and details how it is utilized.

AN-1270: ADV7511/ADV7511W/ADV7513 Based Video Generators

This 8-page Application Note shows a basic configuration in which a field-programmable gate array (FPGA) is used as a signal source, producing sync timing and a video pattern, and the ADV7511/ADV7511W/ADV7513 are configured to output a valid High-Definition Multimedia Interface (HDMI®) or digital visual interface (DVI) stream—focusing on the most basic example to illustrate ways of generating a valid video stream.

AN-1260: Crystal Design Considerations for Video Decoders, HDMI Receivers, and Transceivers

This 3-page Application Note helps designers to achieve frequency stability and accuracy for the external oscillators used with video decoders, which typically require a 28.63636-MHz crystal with 50-ppm frequency stability in fundamental mode.

AN-1256: Manual Scaling in the ADV7186

This 4-page Application Note describes the automatic and manual scaling algorithms used in the ADV7186 video decoder. Upscaling changes a low resolution video input to a higher resolution video output; downscaling changes a high resolution video input to a lower resolution video output to satisfy the back end device without the need for external memory.

AN-1249: Converting 3D Images to 2D Images Using the ADV8003 Evaluation Boards

The ADV8003 video signal processor with TTL logic and serial video inputs can de-interlace and scale input video. It generates and blends a bitmap-based on-screen display and provides the blended video to one or more output. Other available outputs include two HDMI transmitters, a six-DAC encoder with SD and HD support, and a TTL output. This application note describes how to pass 3D video through the ADV8003 and convert the 3D image to a 2D image.

Circuits from the Lab

CN0296: Low Cost, High Performance Sound Bar System

This low-cost, high-performance sound bar system can accept an analog stereo audio signal as an input and output up to eight channels of audio with discrete processing on each channel. The circuit offers low power consumption and high efficiency without sacrificing audio quality, making it ideal for small docking stations and portable media devices. The circuit is capable of driving headphones without the need of additional components. The ADAU1761 low power, stereo audio codec with integrated SigmaDSP® digital audio processing accepts two audio channels. It is optimized for audio applications and programmed using SigmaStudio development software for ease of use and faster development. The output of the ADAU1761 can send up to eight channels of digital audio data to the output amplifiers using the serial interface. The ADAU1761 allows different audio signal processing in each channel, such as volume control, custom equalization, filtering, and spatialization effects tuned to the specific speaker configuration. The ADAU1761 processes and converts analog audio to digital format and drives the SSM2518 power amplifier. The SSM2518 is a digital input class-D audio power amplifier that can output two channels of audio with a continuous power of 2 watts each into a 4 Ω load. The channel-mapping feature of the SSM2518 allows it to select the specific channel to output among those that are available in the interface, making it ideal for surround sound applications.

CN0284: High-Performance, Low-Noise Studio Microphone with MEMS Microphones, Analog Beamforming, and Power Management

This professional-grade studio or live-performance microphone uses up to 32 analog MEMS microphones connected to op amps and a difference amplifier. Designed for low noise, its output is linear for acoustic inputs up to 131 dB SPL. Powered from a single 9-V battery, the ±9-V and 1.8-V power rails are generated from two voltage regulators. The ADMP411, which consists of a MEMS microphone element and an impedance-matching amplifier, has a frequency response that is flat to 28 Hz, making it ideal for full-bandwidth, wide dynamic range audio capture.

USB Powered DVI/HDMI-to-VGA Converter (HDMI2VGA) with Audio Extraction (CN0282)

This circuit provides a complete solution for converting HDMI/DVI to VGA (HDMI2VGA) with an analog audio output. Using the low-power ADV7611 HDMI receiver, it is capable of receiving video streams up to 165 MHz. Powered from a USB cable, it works for resolutions up to 1600 × 1200 at 60 Hz. The circuit uses EDID content to ensure that the video stream from the HDMI/ DVI source is at the highest possible resolution supported by the HDMI source, converter, and VGA display.

Low Noise Analog MEMS Microphone and Preamp with Compression and Noise Gating (CN0262)

This circuit interfaces an analog MEMS microphone to a microphone preamp. The ADMP504 consists of a MEMS microphone element and an output amplifier. Analog Devices’ MEMS microphones have a high signal-to-noise ratio (SNR) and a flat wideband frequency response, making them an excellent choice for high-performance, low-power applications. The SSM2167 low-voltage, low-noise mono microphone preamp is a good choice for use in low-power audio signal chains. This preamp includes built-in compression and noise gating, which gives it an advantage for this function over using just an op amp in the preamp circuit. Compressing the dynamic range of the microphone signal can reduce the peak signal levels and add additional gain to low level signals. Noise gating attenuates the level of signals below a certain threshold, so that only desired signals, such as speech, are amplified, and noise in the output signal is reduced. These features help to improve the intelligibility of the voice signal picked up by the microphone.

New Product Briefs

July 2014

NatureVue™ Video Signal Processor with bitmap OSD, dual HDMI Tx, encoder

adv8005The ADV8005 multiple input video signal processor can deinterlace and scale standard definition (SD), enhanced definition (ED), or high definition (HD) video data to ultra HD formats; generate a bitmap on-screen display (OSD); and output the video with OSD overlaid on two HDMI transmitters and a video encoder. The 60-bit video port can be flexibly configured and used to input two individual video streams. The TMDS receiver port can be used to input video signals up to UHD resolution. Primary and secondary video scalers enable simultaneous output of multiple video signals with different resolutions, upscaling to UHD, 1080p, UXGA graphics, and other VESA modes. The device can also downscale UHD to other lower formats. Video can be output using one or both HDMI transmitters and/or the six-DAC SD/HD video encoders. The six 12-bit NSV video DACs allow composite (CVBS), S-Video (Y/C), and component (YPrPb) analog outputs in standard, enhanced, and high definition video formats. The HDMI transmitters support UHD and all mandatory 3D video resolutions. Each transmitter features an audio return channel receiver (ARC). The device can receive up to eight channels of I2S, S/PDIF, direct stream digital (DSD), and high bit rate (HBR) audio from the serial video Rx or external audio input pins. The Blimp OSD development tool assists in design, debug, and emulation. The ADV8005 operates on 1.8-V and 3.3-V supplies. Available in a 425-ball CSP-BGA package, it is specified from 0°C to 70°C and priced from $42.65 in 1000s.

June 2014

2.5-W Class-D Power Amplifier includes boost converter

ssm4567The SSM4567 digital-input Class-D power amplifier includes a boost converter, allowing it to provide a constant maximum output power across the battery voltage range. Combining an audio DAC, power amplifier, and PDM or PCM digital audio interfaces on a single chip, it is ideal for power-sensitive applications, such as mobile phones, tablets, and portable media players, where system noise can corrupt the small analog signal sent to the amplifier. Audio can be transmitted digitally to the audio amplifier, significantly reducing the effect of noise sources on the transmitted audio and eliminating the need for input coupling capacitors. The amplifier can deliver 2.5 W of continuous output power with <1% THD + N driving a 4-Ω load from a 3.6-V supply. Operating on 1.8-V and 3.6-V supplies, the SSM4567 dissipates 20 mW in normal mode and 6 µW in shutdown mode. Available in a 19-ball WLCSP package, it is specified from –40°C to +85°C and priced at $0.95 in 1000s.

Blackfin Embedded Processors

adsp-bf51xThe ADSP-BF514F16 and ADSP-BF518F16 processors, members of the Blackfin® family, incorporate the Analog Devices/Intel Micro Signal Architecture, which combines a state-of-the-art dual-MAC signal-processing engine, a clean, orthogonal RISC-like microprocessor instruction set, and single-instruction, multiple-data multimedia capabilities. The processor core contains two 16-bit multipliers, two 40-bit accumulators, two 40-bit ALUs, four video ALUs, and a 40-bit shifter. The rich set of industry-leading system peripherals and memory makes the processors the platform of choice for next-generation applications. The devices include an RSI controller, a TWI controller, two UART ports, two SPI ports, two serial ports (SPORTs), nine general-purpose 32-bit timers (eight with PWM capability), 3-phase PWM for motor control, a real-time clock, a watchdog timer, and a parallel peripheral interface (PPI). The ADSP-BF518F16 adds an IEEE-compliant 802.3 10/100 Ethernet MAC with IEEE-1588 support. Available in CSP-BGA and LQFP packages, the ADSP-BF514F16/518F16 are specified from –40°C to +85°C and priced at $10.31/$11.46 in 1000s.

Technical Articles

Witold Kaczurba, FPGA-Based System Combines Two Video Streams to Provide 3D Video, Analog Dialogue, 2013-12-02

Michael Corrigan & Joe Triggs, CRC testing in video applications, EDN, 2013-09-10

Jeff Ugalde, Ian Beavers, and Lie Dou, Deliver Quad-HD Video Over HDMI Cables, Electronic Design, 2013-03-05

Witold Kaczurba and Brett Li, HDMI Made Easy: HDMI-to-VGA and VGA-to-HDMI Converters, Analog Dialogue, 2013-02-04

Webinars and Tutorials

What is a "Wide Dynamic Range" Microphone and why does it matter to my design? - MEMS microphones with the capability to capture very high sound pressure acoustic waves (loud noises) with high fidelity hold the potential to improve user experience in audio capture and to make acoustic detection viable for a range of applications that might have previously been unsuitable for such methods. We'll discuss design considerations for these microphones and applications that might benefit from such high performance.

 

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