FSTU3257 Datasheet, PDF (1/7 Pages) Fairchild Semiconductor – Quad 2:1 Multiplexer/Demultiplexer Bus Switch with -2V Undershoot Protection

August 1999
Revised April 2000
FSTU3257
Quad 2:1 Multiplexer/Demultiplexer Bus Switch
with −2V Undershoot Protection
General Description
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.
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 Under-
shoot 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.
Features
s Undershoot hardened to −2V (A and B Ports)
s Soft enable turn-on to minimize bus to bus charge
sharing during enable
s 4Ω switch connection between two ports.
s Minimal propagation delay through the switch.
s Low l_CC.
s Zero bounce in flow-through mode.
s Control inputs compatible with TTL level.
s See Applications Note AN-5008 for details
Ordering Code:
Order Number Package Number
Package Description
FSTU3257M
M16A
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