10.2.1.2 Stub Length

When connecting a node to the bus, the distance between the transceiver inputs and the cable trunk, known as the stub, should be as short as possible. Stubs present a non-terminated piece of bus line which can introduce reflections as the length of the stub increases. As a general guideline, the electrical length, or round-trip delay, of a stub should be less than one-tenth of the rise time of the driver, thus giving a maximum physical stub length as shown in Equation 1.

Per Equation 1, Table 3 shows the maximum cable-stub lengths for the minimum driver output rise times of the SN65HVD7x half-duplex family of transceivers for a signal velocity of 78%.