The LMH1297 is a 12G UHD-SDI 75-Ω bidirectional I/O with integrated reclocker. This device can be configured either in input mode as an adaptive cable equalizer or in output mode as a dual cable driver, allowing system designers the flexibility to use a single BNC either as an input or output port, simplifying UHD video hardware designs. The integrated reclocker locks to all supported SMPTE data rates up to 11.88 Gbps in both modes. The bidirectional I/O has an on-chip 75-Ω termination and return loss compensation network that meets the stringent SMPTE return loss requirements.
An additional 75-Ω driver output allows the LMH1297 to support a variety of system functions. In EQ (Equalizer) Mode, this second 75-Ω driver can be used as a loop-through output. In Cable Driver (CD) Mode, this 75-Ω driver can be used as a second fan-out cable driver. The host-side 100-Ω driver can also be used as a loop-back output in CD Mode for monitoring purposes.
The on-chip reclocker attenuates high-frequency jitter and fully regenerates the data using a clean, low-jitter clock. The reclocker has a built-in loop filter and does not require any input reference clock. The LMH1297 also has an internal eye opening monitor and a programmable pin for CDR lock indication, input carrier detect, or hardware interrupts to support system diagnostics and board bring-up.
The LMH1297 is powered from a single 2.5-V supply. It is offered in a small 5-mm × 5-mm, 32-pin QFN package.