LMH0318 3 Gbps HD/SD SDI Reclocker with Integrated Cable Driver
1 Features
- Supports ST 424(3G), 292(HD), 259(SD), MADI, and DVB-ASI
- Locks to rates 2.97 Gbps, 1.485 Gbps, or Divided by 1.001 sub-rates, and DVB-ASI
- Reference-free Operation with Fast Lock Time covering all Supported or Selected Data Rates
- 75 Ω and 100 Ω Transmitter Outputs
- Integrated 2:1 Mux Input, 1:2 Demux/Fanout Outputs
- Automatic Slew Rate Based on Input Rate Detect
- On-chip Eye Monitor
- Low 300 mW Power Consumption With Automatic Power Down On Loss Of Input Signal
- Programmable via SPI, Or SMBus Interface
- Single 2.5 V Supply Operation
- Small 4 mm × 4 mm 24-pin QFN Package
- -40°C to +85°C Operating Temperature Range
- Footprint compatible with LMH1218 for easy upgrade to 12G
2 Applications
- SMPTE Compatible Serial Digital Interface (SDI)
- Broadcast Video Routers, Switches, and Monitors
- Digital Video Processing and Editing
- DVB-ASI and Distribution Amplifiers
3 Description
The LMH0318 is a 3 Gbps HD/SD SDI Reclocker with Integrated Cable Driver designed to drive serial video data compatible to SMPTE-SDI and DVB-ASI standards. The clock and data recovery circuit eliminates accumulated jitter and detects the incoming data rate without requiring an external reference clock. The integrated driver with 75 ohm and 50 ohm outputs enables multiple media options such as coax and FR4 PCB.
Device Information(1)
| PART NUMBER | PACKAGE | BODY SIZE (NOM) |
|---|---|---|
| LMH0318 | WQFN (24) | 4 mm × 4 mm |
- For all available packages, see the orderable addendum at the end of the data sheet.
Simplified SPI Schematic
4 Revision History
| DATE | REVISION | NOTES |
|---|---|---|
| September 2015 | * | Initial release. |
5 Description continued
The integrated 2-to-1 MUX on the input of the LMH0318 enables selection between two video sources, while the programmable equalizer compensates for the PC board loss to extend signal reach. With a wide range clock-and-data recovery (CDR) circuit, the on-chip reclocker automatically detects and locks to serial data from 270 Mbps to 2.97 Gbps without the need for an external reference clock and loop filter component, thereby simplifying board design and lowering system cost. The reclocked serial data can be routed to either the 75 Ω or 50 Ω transmitter output, or both simultaneously (1-to-2 fanout mode). The output voltage swing is compatible to ST 424, 344, 292, and 259 standards.
A non-disruptive eye monitor allows for real-time measurement of serial data to simplify system startup or field tuning. The LMH0318 is pin compatible with the LMH1218, 12 Gbps Cable Driver with Integrated Reclocker.