DSG5E Reference Generator
E1 G.703/AES Synchronizer
A crystal controlled reference and master clock generator. A powerful building block, used when asynchronous digital output modules installed in the GPU frame has to be synchronized by the GPU bus. It synchronizes all digital outputs by means of an internal AES GRADE 1 crystal oscillator, able to phase lock to an AMI (Alternate Mark Inversion) coded 2Mbit E1 CCITT G.703 signal, a 2.048 MHz. E1clock or a 10 MHz clock from GPS receivers.
Besides controlling the modules via the GPU bus, two 75 Ohms Word outputs and two 110 Ohms RS422 transformer balanced AES outputs are available on the back panel. 44.1 kHz, 48 kHz or 96 kHz sampling frequency is selected by the pushbutton on the front.
The Generator has a transformer balanced E1 line receiver interface, which performs clock recovery and jitter attenuation by means of a local crystal controlled reference. It phase locks the AES and word output sampling frequency to the incoming sync by an advanced two step phase lock process, providing an impressive jitter and wander attenuation which enables the generator to clean up and stabilize an erratic and jittery house sync.
The input circuit has a jitter tolerance exceeding the requirements of publications 43802,43801, 62411 amended, TR-TSY-000170 and CCITT REC. G.823.
The overall design is based on an extensive sync safety philosophy, featuring a unique glide principle and an internal flywheel, guarding efficiently against sync drop outs. The reference is automatically selected by priority: 1: E1 G.703, 2: 2.048 MHz, 3: 10 MHz, 4: Internal crystal.
