FSTU3257QSCX

FSTU3257QSCX Datasheet

FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection

Part	Datasheet
FSTU3257QSCX	FSTU3257QSCX (pdf)

Related Parts	Information
FSTU3257MTCX	FSTU3257MTCX

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FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection 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 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. s Undershoot hardened to −2V A and B Ports s Soft enable turn-on to minimize bus to bus charge sharing during enable s switch connection between two ports. s Minimal propagation delay through the switch. s Low lCC. 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, Narrow FSTU3257QSC MQA16 16-Lead Quarter Size Outline Package QSOP , JEDEC MO-137, 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. is a trademark of Fairchild Semiconductor Corporation. 2000 Fairchild Semiconductor Corporation DS500302 FSTU3257 Logic Diagram Connection Diagram Pin Descriptions Pin Name OE S A Bus Switch Enable Select Input Bus A Bus B Truth Table Function Disconnect A = B1 A = B2 FSTU3257 Absolute Maximum Ratings Note 1 Supply Voltage VCC DC Switch Voltage VS Note 2 DC Input Control Pin Voltage VIN Note 3 DC Input Diode Current lIK VIN<0V DC Output IOUT DC VCC/GND Current ICC/IGND Storage Temperature Range TSTG −0.5V to +7.0V −2.0V to +7.0V −0.5V to +7.0V −50mA 128mA +/− 100mA −65°C to +150 °C Recommended Operating Conditions Note 4 Power Supply Operating VCC Input Voltage VIN Output Voltage VOUT Input Rise and Fall Time tr, tf Switch Control Input 4.0V to 5.5V 0V to 5.5V 0V to 5.5V 0nS/V to 5nS/V Switch I/O 0nS/V to DC Free Air Operating Temperature TA −40 °C to +85 °C Note 1 The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum rating. The Recommended Operating Conditions tables will define the conditions for actual device operation. Note 2 VS is the voltage observed/applied at either the A or B Ports across the switch. Note 3 The input and output negative voltage ratings may be exceeded if the input and output diode current ratings are observed. Note 4 Unused control inputs must be held HIGH or LOW. They may not float. DC Electrical Characteristics Parameter TA = −40 °C to +85 °C Typ Note 5 Units Conditions VIK VIH VIL II IOZ RON VIKU Clamp Diode Voltage HIGH Level Input Voltage LOW Level Input Voltage Input Leakage Current OFF-STATE Leakage Current Switch On Resistance Note 6 Quiescent Supply Current Increase in ICC per Input Voltage Undershoot IIN = −18mA

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FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection

FSTU3257

Quad 2:1 Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection

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 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.
s Undershoot hardened to −2V A and B Ports s Soft enable turn-on to minimize bus to bus charge
sharing during enable s switch connection between two ports. s Minimal propagation delay through the switch. s Low lCC. 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, Narrow

FSTU3257QSC

MQA16
16-Lead Quarter Size Outline Package QSOP , JEDEC MO-137, 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.
is a trademark of Fairchild Semiconductor Corporation.
2000 Fairchild Semiconductor Corporation DS500302

FSTU3257

Logic Diagram

Connection Diagram

Pin Descriptions

Pin Name OE S A

Bus Switch Enable Select Input Bus A Bus B

Truth Table

Function Disconnect

A = B1 A = B2

FSTU3257

Absolute Maximum Ratings Note 1

Supply Voltage VCC DC Switch Voltage VS Note 2 DC Input Control Pin Voltage VIN Note 3 DC Input Diode Current lIK VIN<0V DC Output IOUT DC VCC/GND Current ICC/IGND Storage Temperature Range TSTG
−0.5V to +7.0V −2.0V to +7.0V −0.5V to +7.0V
−50mA 128mA +/− 100mA −65°C to +150 °C

Recommended Operating Conditions Note 4

Power Supply Operating VCC Input Voltage VIN Output Voltage VOUT Input Rise and Fall Time tr, tf

Switch Control Input
4.0V to 5.5V 0V to 5.5V 0V to 5.5V
0nS/V to 5nS/V

Switch I/O
0nS/V to DC

Free Air Operating Temperature TA −40 °C to +85 °C

Note 1 The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum rating. The Recommended Operating Conditions tables will define the conditions for actual device operation.

Note 2 VS is the voltage observed/applied at either the A or B Ports across the switch.

Note 3 The input and output negative voltage ratings may be exceeded if the input and output diode current ratings are observed.

Note 4 Unused control inputs must be held HIGH or LOW. They may not float.

DC Electrical Characteristics

Parameter

TA = −40 °C to +85 °C

Typ Note 5

Units

Conditions

VIK VIH VIL II IOZ RON

VIKU

Clamp Diode Voltage HIGH Level Input Voltage LOW Level Input Voltage Input Leakage Current OFF-STATE Leakage Current Switch On Resistance Note 6

Quiescent Supply Current Increase in ICC per Input

Voltage Undershoot

IIN = −18mA

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Datasheet ID: FSTU3257QSCX 515556