7.1 Overview

The LMH1219 is a SMPTE compatible, low-power UHD adaptive cable equalizer with integrated reclocker. The LMH1219 has two inputs: a 75-Ω cable equalizer and a 100-Ω PCB (printed circuit board) equalizer. The 75-Ω cable equalizer input features an internal 75-Ω termination and compensation network for meeting stringent SMPTE return loss requirements. The 100-Ω PCB equalizer input supports high speed signals across differential PCB traces that connect to an external SFF-8431 optical module or on-board FPGA. An internal 2:1 input mux allows users to select between the 75-Ω cable equalizer and the 100-Ω PCB equalizer. The selected input then passes through a multi-rate reclocker with a built-in loop-filter. The multi-rate reclocker is compatible with SMPTE data rates (11.88, 5.94, 2.97, 1.485 Gbps, 270 Mbps) and their divide-by-1.001 sub-rates. It is also compatible with the 10 GbE data rate (10.3125 Gbps). After the reclocker, an internal 1:2 fan-out mux allows users to select the data or clock content for each output. At both outputs, the LMH1219 has 100-Ω drivers with de-emphasis. The de-emphasis feature of the drivers is designed to compensate for insertion loss caused by output PCB traces.

The operating mode of the LMH1219 can be set by 4-level control pins, SPI, or SMBus serial control interface. The LMH1219 can be powered from a single 2.5 V supply or dual 2.5 V/1.8 V supplies for lower power consumption. The LMH1219 is offered in a small 4 mm x 4 mm 24-lead QFN package.