3G/HD/SD-SDI Low Power Quad Reclocker
The M21355 is a quad serial digital video reclocker with integrated trace equalization, automatic rate detect (ARD) circuitry, and a 16:4 crosspoint switch at the input. It operates at SDI data rates ranging from 270 Mbps to 2970 Mbps and is compliant to SMPTE 424M, SMPTE292M, and SMPTE 259M. At 270 Mbps, it also supports DVB-ASI.
The M21355 has an input jitter tolerance (IJT) of greater than 0.6 unit intervals (UI) and can provide retimed serial outputs with very low output jitter. The quad reclocker requires a single, external, 27 MHz crystal, which is used as the reference clock for all four channels. It includes per-lane analog input equalization for up to 40" of FR4 trace and two connectors in addition to output de-emphasis.
This device features integrated supply regulators, allowing it to be powered from 1.2 V, 1.8 V, 2.5 V, or 3.3 V supply voltages. When operating at 1.2 V, it consumes only 160 mW per channel at 3G-SDI. Furthermore, the power rails for the core, input, and output circuitry are electrically isolated on-chip and as such may be connected to different voltage rails on the board. This feature enables the M21355 to be DC coupled to any upstream or downstream device regardless of its input/output voltage level.