Which stands for Low Voltage Differential Signaling. Also known as TIA/EIA-644.

It is a means for transmitting data at high speeds which is resilient to noise. Currently, you can send data along twisted pair at around 650 Megabits per second. On a lossless wire, data rates of 1.923Gbit/s can be achieved.

Here is how it works:

The data is differential, meaning to send one bit requires two wires with one of the wires having the opposite bit then the other. The reason for this is an noise which gets picked up by the wires, can be canceled about at the receiver.

This is why it can be used for high speed applications. Higher speeds make the data more susceptible to noise and LVDS helps reduce the amount of noise on the line.

LVDS is also, low voltage. Meaning the voltage swing, or difference, between the two lines is about half a voltage. It is much faster to bring a signal up one volt than it is to bring a signal up to 5 volts.

Remember, voltage and current cannot be changed instantaneously. There is a delay time between going from ground and your voltage level.

With a fast swing time - data can change from a 1 to 0 or a 0 to 1 much faster - and differential signals, LVDS is a good choice for when you need to send large amounts of data very fast over copper lines.

LVDS chips have current-mode drivers which is why on the receiver end a 100 ohm resistor must be placed between the differential signals. With the current flowing across the resistor, the small differential voltage is created.

The differential signals should also run side by side so any noise will be picked up equally across both wires and then canceled out.

Log in or register to write something here or to contact authors.