3/2/2023 0 Comments Digital audio word clockMaster Clock Generator for AES, Word Clock & HD/SD Video Black and Burst.įor more information, please visit this product's webpage. Broadcast Pack Option – Adds Ovened crystal for AES-3 Grade 1(better than 0.7ppm over 12months) output reference and dual mains inlets and dual power supplies. Tamper proof front panel “lockout” switch. GPI 9way D connector giving front panel memory setting remote control and PSU & Genlock status. Memory settings for up to 3 individual recallable input/output configurations. Ultra low jitter performance & ultra high frequency stability using true DDS direct digital synthesis. Pull up/down sample rate adjustable to suit all film, video and audio applications. Simultaneous AES & Word Clock outputs genlocked and phase coherent to input reference. HD & SD outputs can be genlocked to any input reference or set as master house sync. All SD frame rates selectable and available independently of HD outputs. All HD frame rates selectable in progressive scan & interlaced 1080 or 720. Selectable input reference with auto detection of video formats. The expression ‘word clock’ is also used at circuit-board level to describe various sampling-frequency logic signals.Master Clock Generator especially designed to cater for all video and digital audio synchronisation requirements within the post-production, studio & broadcasting industry. Word Clock is a handshake signal, typically running at 44.1KHz or 48KHz, used to signal the timing of digital audio data words. Where new equipment is designed to use a word-clock signal, it is recommended that the rising edge is treated as the timing reference point. Video amplifiers can usually handle a peak-to-peak signal of 2 V, AC coupled or rather more than 1 V DC coupled and drive a terminating load of 75 Ohms. It should be noted that TTL signals are difficult to distribute using distribution amplifiers, and no common distribution amplifiers (video, AES3 or audio etc.) handle this signal, so that the loop-through architecture is the usual option. Any practical technique may be used to detect the edges of the signal. Then adapters containing capacitors or attenuators may be used to suit individual receivers. The driver level most likely to provide the functionality required is a full 5 V, DC coupled, and able to drive a 75 Ohm load. Making it impossible to design a driver guaranteed to operate with all receivers. Some receivers are known to fail when the peak-to-peak signal exceeds 3 V, and others are known to require at least 4 V. These require a logic ‘low’ of less that 0.4 V and a logic ‘high’ greater than 2.4 V. Receiving devices may require AC or DC coupling, and any peak-to-peak level from 1 V to 5 V, TTL logic levels being quite common. It may be required to sink the current for a number of transistor-transistor-logic (TTL) inputs, or drive a 75 Ohm resistive load. The transmitted signal may vary in peak-to-peak amplitude from 1 V up to 5 V, and be either AC or DC coupled. The signal is commonly carried on coaxial cable, so that a single output can synchronise several receiving equipments by looping the signal through each in turn, and possibly terminating the cable with a 75 Ohm resistor at the far end. This signal is not standardised and the parameters quoted are merely examples. It is used between different pieces of equipment to provide sampling frequency clocking of various sources. It is possible to meet all the timing requirements of AES11 by means of a square wave at sampling frequency basic rate, commonly called word clock. “AES recommended practice for digital audio engineering – Synchronization of digital audio equipment in studio operations” Annex B (Informative) Word Clock
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