Search results
Results from the WOW.Com Content Network
Differential signalling is a method for electrically transmitting information using two complementary signals. The technique sends the same electrical signal as a differential pair of signals, each in its own conductor. The pair of conductors can be wires in a twisted-pair or ribbon cable or traces on a printed circuit board.
Low-voltage differential signaling (LVDS), also known as TIA/EIA-644, is a technical standard that specifies electrical characteristics of a differential, serial signaling standard. LVDS operates at low power and can run at very high speeds using inexpensive twisted-pair copper cables.
Current mode logic (CML), or source-coupled logic (SCL), is a digital design style used both for logic gates and for board-level digital signaling of digital data.. The basic principle of CML is that current from a constant current generator is steered between two alternate paths depending on whether a logic zero or logic one is being represented.
Low-voltage positive emitter-coupled logic (LVPECL) is a power-optimized version of PECL, using a positive 3.3 V instead of 5 V supply. PECL and LVPECL are differential-signaling systems and are mainly used in high-speed and clock-distribution circuits. A common misconception is that PECL devices are slightly different from ECL devices.
RS-422 uses a nominal 0 to 5-volt signal, while MIL-STD-188-114B uses a signal symmetric about 0 V. However, the tolerance for common-mode voltage in both specifications allows them to interoperate. Care must be taken with the termination network. RS-423 is a similar specification for unbalanced signaling.
After line coding, the signal is put through a physical communication channel, either a transmission medium or data storage medium. [3] [4] The most common physical channels are: the line-coded signal can directly be put on a transmission line, in the form of variations of the voltage or current (often using differential signaling).
ARINC 429 is a data transfer standard for aircraft avionics. It uses a self-clocking, self-synchronizing data bus protocol (Tx and Rx are on separate ports). The physical connection wires are twisted pairs carrying balanced differential signaling.
With a differential pair of wires, roughly the same unwanted voltage is induced in each wire. The receiver subtracts the voltages on the two wires, so that the unwanted voltage disappears, and only the voltage created by the driver remains. A second advantage of differential TTL is that the differential pair of wires can form a current loop. [5]