FSTU3257QSCX

Revised April 2000 FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection General Description Features The Fairchild Switch FSTU3257 is a quad 2:1 high-speed CMOS TTL-compatible multiplexer/demultiplexer bus switch. The low on resistance of the switch allows inputs to be connected to outputs without adding propagation delay or generating additional ground bounce noise. ■ Undershoot hardened to −2V (A and B Ports) When OE is LOW, the select pin connects the A Port to the selected B Port output. The A and B Ports are “undershoot hardened” with UHC protection to support an extended range of 2.0V below ground. Fairchild’s integrated Undershoot Hardened Circuit UHC senses undershoot at the I/O and responds by preventing voltage differentials from developing and turning on the switch. When OE is HIGH, the switch is OPEN and a high-impedance state exists between the two ports. ■ Soft enable turn-on to minimize bus to bus charge sharing during enable ■ 4Ω switch connection between two ports. ■ Minimal propagation delay through the switch. ■ Low lCC. ■ Zero bounce in flow-through mode. ■ Control inputs compatible with TTL level. ■ See Applications Note AN-5008 for details Ordering Code: Order Number FSTU3257M Package Number M16A Package Description 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow FSTU3257QSC MQA16 16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150 Wide FSTU3257MTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code. UHC is a trademark of Fairchild Semiconductor Corporation. © 2000 Fairchild Semiconductor Corporation DS500302 www.fairchildsemi.com FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection August 1999 FSTU3257 Logic Diagram Connection Diagram Pin Descriptions Truth Table Pin Name Description S OE Function OE Bus Switch Enable X H Disconnect S Select Input L L A = B1 A Bus A H L A = B2 B1–B2 Bus B www.fairchildsemi.com 2 Recommended Operating Conditions (Note 4) Supply Voltage (VCC) −0.5V to +7.0V DC Switch Voltage (VS) (Note 2) −2.0V to +7.0V Power Supply Operating (VCC) DC Input Control Pin Voltage (VIN)(Note 3) −0.5V to +7.0V Input Voltage (VIN) 0V to 5.5V 0V to 5.5V DC Input Diode Current (lIK) VIN