What is intra pair?

Intra-pair skew is the term used to define the difference between the etch length of the + and – lane of a differential pair. Inter-pair skew is used to describe the difference between the etch lengths of a differential pair from another differential pair of the same group.

What is differential pairing?

In differential signaling, each signal is transmitted using a differential pair—the signal carried by one wire is the same level as the one carried by the other wire, but in opposite polarity. The signal at the receiving end is interpreted as the difference between the two lines that make up the differential pair.

How do you route differential pairs?

Differential pairs are routed as a pair – that is, you route two nets simultaneously. To route a differential pair, select Interactive Differential Pair Routing from the Route menu. You will be prompted to select one of the nets in the pair, click on either to start routing.

Why does PCI E use differential pairs for links?

The PCIe protocol uses differential pair routing, which requires greater care to meet the impedance targets on these signals versus other single-ended interfaces. Variations in the impedance of these signals will impact the overall jitter and loss within the system.

What is the differential impedance of a USB interface?

The USB 2.0 specification defines a differential characteristic impedance of 90 ohms, plus or minus 15%, for the USB 2.0 differential pair. The USB 3.0 specification defines a differential characteristic impedance range of 72 ohms to 120 ohms.

What is BJT differential pair?

INTRODUCTION. The typical BJT differential pair amplifier consists of a pair of transistors coupled at the emitters to a current source, having equal resistances in each collector and equal but opposite, signal sources in each base. The amplifier has several variations on this basic configuration.

Is USB a differential?

USB uses a differential signaling for data transmission, which is encoded using NRZI and is bit-stuffed to ensure adequate transitions in the data stream for reliable clock recovery.

When would you use a differential pair?

The main reason differential pairs are used in long links that might cross between two boards is their immunity to ground offsets. A ground offset at AC or DC can be thought of as common-mode noise; it is a disturbance in the signal that affects each side of the pair in the same phase and magnitude.

What is differential Signalling and why is it used?

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.

Is Ethernet a differential?

The PHY-side Ethernet wiring has both intra-pair differential and common-mode impedance coupling to ground (generally, 100 and 50 ohms, respectively.) The field-wire side of Ethernet only has intra-pair differential coupling (100 ohms) and no common-mode impedance to any reference (more on that below.)

Is USB differential pair?

In USB, signals are transmitted using differential signaling. USB 2.0 uses a single differential pair of signals, DP and DM. The USB 3.0 specification adds super-speed signaling using two additional sets of differential pairs, SSTX and SSRX, to support a separate, full-duplex connection.

What is differential amplifier using BJT?