STMicroelectronics has introduced a set of four high-speed CMOS 20bit bus switches that are pin-compatible with existing TTL parts. They are designed for use in applications such as PCI hot card insertion and voltage level translation, notebook docking stations, memory interleaving and general-purpose switching.
The parts are compatible with TTL outputs and operate from supply voltages of 4 V to 5.5 V. They have power-down protection on the inputs and outputs and are designed with improved latch-up immunity and an ESD protection to 2 KV. This makes them suitable for use in applications where equipment is plugged and unplugged while powered. The parts also have a high Off resistance and a low On resistance, to maximize isolation when Off and minimize loading when On. Power dissipation is typically 1µA
The B5S16861 is a high-speed CMOS 20bit two-port bus switch, which can be controlled as two 10bit buses or one 20bit bus. Typical delay is a maximum of 0.25 ns at 4.5 V. The on resistance between two ports is typically 5 ohm.
The B5S162861 differs by having a 25 ohm series resistor in each output. This reduces noise resulting from reflections on the driven line, eliminating the need for an external terminating resistor. The typical delay is a maximum of 1.25 ns at 4.5 V. The on resistance between two ports is typically 25 ohm.
The B5S16862 has four enable lines so it can be configured as four 5bit buses or one 20bit bus. The typical delay of the device is a maximum of 0.25 ns at 4.5 V. The on resistance between two ports is typically 5 ohm.
The B5S162862 has four enable lines so it can be configured as four 5bit buses or one 20bit bus. Each output also has a 25 ohm series resistor, reducing reflection noise. The typical delay of the device is a maximum of 1.25 ns at 4.5 V. The on resistance between two ports is typically 25 ohm.
The parts are available in TSSOP48 package.
