Fairchild Semiconductor Introduces the FSTU3257 Bus Switch

Fairchild Semiconductor Corp. (South Portland, ME) recently introduced the FSTU3257, a quad 2:1 high-speed CMOS TTL-compatible multiplexer/demultiplexer bus switch. FSTU switches are used to isolate peripheral and network interface cards from their bus (PCI or CompactPCI) during live insertion and withdrawal. The undershoot-protected FSTU switches block unintended data from the bus by maintaining the data bus and interface cards in an isolated state, even when undershoot conditions occur on an I/O data port.

The FSTU family incorporates a patented Undershoot Hardened Circuitry feature that prevents the turn-on of embedded parasitic bipolar elements. This is designed to ensure against the momentary loss of isolation and corruption of data. The FSTU3257 features low on-resistance, resulting in minimal propagation delay between inputs and outputs and no generation of additional ground bounce.

Other features of the FSTU3257 include soft-enable turn-on to minimize bus-to-bus charge sharing during enable, a four-ohm switch connection between two ports, control inputs compatible with TTL levels and zero-bounce in flow-through mode.

In quantities of 10,000, pricing for the FSTU3257 is $0.40 each.