Method and apparatus for reducing back-to-back voltage glitch on high speed data bus. A voltage or current across such a resistor can form a reference bias current, which can then be used to bias the output devices , Hot-pluggable compatibility is achieved by a reduction in power-off leakage current and short circuit current protection. The low common-mode voltage the average of the voltages on the two wires of about 1. Apparatus and methods provide low voltage differential signaling LVDS driver with replica circuit biasing and protection for hot plugging. The controlling of the activation of the output devices , prevents excessive current flow, and thereby prevents the corresponding damage from excessive current flow. The apparatus of claim 2 , wherein the circuit is configured to carry digital data.

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The integration of the serializer and deserializer components in the control unit due to low demands on additional hardware and software simple and inexpensive. In serial communications, multiple single-ended signals are serialized into a single differential pair with a data rate equal to that of all the combined single-ended channels.

Low-voltage differential signaling

The devices for converting between serial and parallel data are the serializer and deserializer, abbreviated to SerDes when the two devices are contained in one integrated circuit. One embodiment further includes output impedance control.

LVDS works in both parallel and serial data transmission.

In addition, the transmitters need to tolerate the possibility of other transmitters simultaneously driving the same bus. LVDS is growing in popularity for differential data transmission because it features relatively high speed and relatively low-power. LVDS self-terminatinb differential data transmission to reduce susceptibility to common-mode noise.


The resistance of the pullup resistors is not critical, as the recovery can be slow. For example, many conventional LVDS drivers use a constant current source with some sort of replica feedback to control either the common mode or differential signaling. As illustrated in FIG.

US7898295B1 – Hot-pluggable differential signaling driver – Google Patents

A local powered-off LVDS driver local power supply of sqing driver is held at low-logic level or ground should not interfere when logic high exists on the shared bus. For example, a 7-bit wide parallel bus serialized into a single pair that will operate at 7 times the data rate of one single-ended channel. The apparatus of claim 1further comprising a feedback circuit configured to control an output impedance of at least the driver NMOS transistor and the driver PMOS transistor. To serve this application, FPD-Link chipsets continued to increase the data-rate and the number of parallel LVDS channels to meet the internal TV requirement for transferring video data from self-tedminating main video processor to the display-panel’s timing controller.

USB1 – Hot-pluggable differential signaling driver – Google Patents

MLVDS has two types of receivers. For example, the level shift circuit can raise the output voltage and the level shift circuit can lower the output voltage. US USB1 en While the short to ground is still present, the output voltage at the driver outputs will be low.

The illustrated protection control circuit has a fault detector and a wake-up or reset circuit However, engineers using the first LVDS products soon wanted to drive self-terjinating receivers with a single transmitter in a multipoint topology. This scaling N by greater than 1 decreases the current passing through the resistor relative to the resistor FIG.

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An alternative is the use of coaxial cables. The apparatus of claim 1wherein the biasing circuit comprises a first biasing circuit and a second biasing circuit: The feedback mechanism can be turned off for most of the time during operation, and calibrated once or in the background when the driver circuit is not busy.

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In the illustrated embodiment, the fault detector comparesthe outputs to a threshold voltage V REF. Such a fault detection feature should be able to detect excessive current then shut off excessive current flow. The control of the steering switchescontrols the output data of the driver. This permits the swing levels to be lower, which significantly reduces power dissipation. Aa example, an explicit resistor, such as an external resistor can self-terminwting used as a reference.

Low-voltage differential signaling – Wikipedia

LVDS technology allows products to address high data rates ranging from, for example, hundreds of Mbps to greater than 2 Gbps. The output impedance can be centered on Z eq and a particular desired output impedance can be achieved by proper sizing of swng transistorsas explained earlier in connection with Equation 1. The apparatus of claim 2wherein each of the steering switches is an NMOS transistor. The illustrated configuration avoids such strongly coupled feedback loops, especially in the signal path.