M-LVDS

M-LVDS (Multipoint Low Voltage Differential Signaling ) is a simple serial bus system with differential signal transmission for use within electronic devices and assemblies , which has a bandwidth of up to 500 Mbit / s .

Compared to previous LVDS systems, which are specified as point-to-point connections , the multipoint variant can be implemented as a bus. By increasing the maximum driver current of the transceiver , up to 32 participants can be switched to the bus. Simultaneous reading of all participants on the bus is provided. If several participants try to write at the same time, the differential voltage on both conductors is automatically limited to ~ 400 mV. This does not damage the driver blocks.

When interpreting the logical states on the lines, a distinction is made between two types. Type 1 interprets the voltage difference symmetrically around 0 V and also takes a hysteresis into account . Type 2, on the other hand, has shifted the plane of symmetry by 100 mV into the positive range. This means that a voltage difference of 0 V can be interpreted as a logical zero if no participant has write access to the bus.

The gross data rates that can be achieved on M-LVDS are between 100 Mbit / s and 500 Mbit / s. It is therefore suitable for the uncompressed transmission of video data streams, for example within liquid crystal displays for controlling the LCD panel.

M-LVDS is standardized in EIA / TIA-899, as an extension of EIA / TIA-644. Integrated driver modules are available for this from various semiconductor manufacturers .