ZHCSIC9D April 2016 – June 2018 LMH1219
PRODUCTION DATA.
SMPTE specifies the requirements for the Serial Digital Interface to transport digital video over coaxial cables. One of the requirements is meeting return loss, which specifies how closely the port resembles 75-Ω impedance across a specified frequency band. The SMPTE specifications also defines the use of AC coupling capacitors for transporting uncompressed serial data streams with heavy low frequency content. The use of 4.7-μF AC coupling capacitors is recommended to avoid low frequency DC wander. SFF-8431 (SFP+) requires the 100-Ω transmit signal to meet the electrical, return loss, jitter, and eye mask specifications. TI recommends placing the LMH1219 as close as possible to the 75-Ω BNC and 100-Ω SFP+ optical module in order to meet the specifications for SMPTE and SFF-8431. Refer to Table 9 for design guidelines.