LVDS (Low Voltage Differential Signaling) is a widely used data transmission method between the display controller and LCD panel, particularly in TFT technology. LVDS allows fast, stable, and power-efficient transfer with low electromagnetic interference. Data is transmitted using differential pairs, ensuring signal integrity even over longer distances and at high resolutions. Though increasingly replaced by modern serial interfaces such as eDP or MIPI DSI, LVDS remains a reliable standard in embedded systems and industrial applications requiring robustness and long-term availability.
How does LVDS work?
LVDS sends data as a small voltage difference on a pair of wires instead of a voltage referenced to ground. The transmitter drives a constant current of about 3.5 mA through a 100 Ω termination resistor at the receiver, producing a swing of roughly 350 mV. The receiver looks only at the difference between the two lines, so noise that couples equally onto both is cancelled, and the opposite currents in the pair keep radiated emissions low.
In displays LVDS is used as FPD-Link: parallel RGB data, sync signals and data enable are serialized onto 3 data pairs (18-bit color) or 4 data pairs (24-bit color) plus one clock pair. Larger or faster panels use dual-channel LVDS, with odd and even pixels sent over two links. The two common bit mappings for 24-bit data, VESA and JEIDA, are not interchangeable – the source must be set to the mapping given in the panel datasheet.
LVDS vs eDP vs MIPI DSI
| LVDS | eDP | MIPI DSI | |
|---|---|---|---|
| Signaling | Differential data pairs + clock pair | DisplayPort lanes, embedded clock | D-PHY data lanes + clock lane |
| Typical link | 4–5 pairs per channel, 1–2 channels | 1, 2 or 4 lanes | 1–4 data lanes |
| Typical displays | Industrial TFTs from about 7″, up to Full HD | Laptops, panel PCs, high resolutions | Small and mid-size displays, mobile SoCs |
| Cable length | Longest of the three | Short, internal | Short, on-board or close to the processor |
| Maturity | Mature, long-term available | Growing in industrial panels | Standard in mobile and embedded processors |
Where is LVDS used today?
LVDS remains the most common interface of industrial LCD-TFT panels from roughly 7 inches upwards, of the industrial computers that drive them and of AD boards. Its strengths are robustness, tolerance of longer cables and long-term availability, which matter in products manufactured for many years. New designs increasingly move to eDP and MIPI DSI, which carry higher resolutions over fewer lines; when a processor has no LVDS output, a bridge chip or an adapter board converts the signal.
What to check when integrating an LVDS display
- Single or dual channel and the number of data pairs (18-bit or 24-bit color).
- Bit mapping – VESA or JEIDA; a mismatch shows up as wrong colors.
- Pixel clock range and panel timings from the datasheet.
- Connector type and pinout on both ends of the cable, including power and backlight control lines.
- Cable length and shielding – keep the pairs twisted and impedance-controlled to limit EMI.
