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Application Notes

AN-1299: Enabling HDMI 2.0 Using ADV8005 and ADV7625/ADV7626/ADV7627

This Application Note shows how to enable the new 4:2:0 feature on the ADV8005 video signal processor and ADV7625/ADV7626/ADV7627 HDMI transceivers. This feature allows receiving and transmitting ultra-HD video with a 60-Hz refresh rate (4k × 2k at 60 Hz) using a 3-GHz bandwidth. The newly introduced format reduces the chroma information for YCrCb, but increases the luma bandwidth. In the 4:2:0 format, two luma samples are sent for one chroma sample, reducing the number of video pixels sent per line.

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

November 2014

Ultralow-power Boost Regulator with MPPT and charge management

adp5090The ADP5090 integrated boost regulator converts dc power from photovoltaic (PV) cells or thermoelectric generators (TEGs) to charge storage elements such as batteries and capacitors, and power small electronic devices in battery-free systems. Efficiently converting harvested power in the 10 μW to 1 mW range, it features sub-μW losses. The internal cold-start circuit allows the regulator to start up with a 380 mV input voltage. Once started, the regulator operates with 100 mV to 3 V input voltages. Open circuit voltage (OCV) sensing, programmable regulation points, and maximum power point tracking (MPPT) allow extraction of the highest possible energy from the PV cell or TEG harvester. A programmable minimum OCV threshold down to 100 mV enables boost shutdown during low light conditions. The charging control function includes rechargeable energy storage protection. An optional primary cell battery can be connected and managed by an integrated power path management control block that automatically switches the power source from energy harvester, rechargeable battery, or primary cell battery. Available in 16-lead LFCSP and TSSOP packages, the ADP5090 is specified from –40°C to +125°C and priced at $1.99 in 1000s.

September 2014

10-Bit, 4× oversampled SDTV Video Decoder with differential inputs, deinterlacer

adv7283The ADV7283 versatile single-chip, multiformat video decoder automatically detects standard analog baseband video signals compatible with worldwide NTSC, PAL, and SECAM standards in the form of composite, S-Video, and component video, and converts them into a YCrCb 4:2:2 data stream that is compatible with the 8-bit ITU-R BT.656 interface standard. The six analog inputs can accept single-ended, pseudo-differential, and fully differential signals. A deinterlacer (I2P converter) enables progressive format video outputs. The video decoder is programmed via a 2-wire, I2C-compatible serial interface. Operating with 1.8-V and 3.3-V supplies, the ADV7283 dissipate 315 mW in normal mode and 1 mW in power-down mode. Qualified for industrial and automotive applications, they are specified from –40°C to +85°C or –40°C to +105°C. Available in 32-lead LFCSP packages, they are priced from $4.95 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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