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IDTQS3251
HIGH-SPEED CMOS QUICKSWITCH 8:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
FEBRUARY 2000
2000 Integrated Device Technology, Inc. DSC-5754/1c
IDTQS3251
INDUSTRIAL TEMPERATURE RANGE
QUICKSWITCH® PRODUCTS
HIGH-SPEED CMOS
QUICKSWITCH 8:1 MUX/DEMUX
FUNCTIONAL BLOCK DIAGRAM
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FEATURES:
• Enhanced N channel FET with no inherent diode to Vcc
•5
ΩΩ
ΩΩ
Ω bidirectional switches connect inputs to outputs
• Pin compatible with the 74F251, 74FCT251, and 74FCT251T
• Zero propagation delay, zero ground bounce
• Undershoot clamp diodes on all switch and control inputs
• TTL-compatible control inputs
• Available in SOIC and QSOP packages
APPLICATIONS:
• Logic replacement
• Video, audio, graphics switching, muxing
• Hot-swapping, hot-docking
• Voltage translation (5V to 3.3V)
DESCRIPTION:
The QS3251 is a high-speed CMOS TTL-compatible 8:1 multiplexer/
demultiplexer. The QS3251 has 3-state outputs. The QS3251 is a function
and pinout compatible version of the 74F251, 74FCT251 and the 74ALS/
AS/LS251 8:1 multiplexers. The low ON resistance of the QS3251 allows
inputs to be connected to outputs without adding propagation delay and
without generating additional ground bounce noise.
Mux/Demux devices provide an order of magnitude faster speed than
equivalent logic devices.
The QS3251 is characterized for operation at -40°C to +85°C.
S0
Y
I0
I1
I2
I3
I4
I5
I6
I7
S1
S2
E
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS3251
HIGH-SPEED CMOS QUICKSWITCH 8:1 MUX/DEMUX
PIN CONFIGURATION
SOIC/ QSOP
TOP VIEW
FUNCTION TABLE(1)
PIN DESCRIPTION
Pin Names I/O Description
I0 - I7I Data Inputs
S0 - S2I Select Inputs
EI Enable Input
Y O Data Output
Symbol Description Max Unit
VTERM(2) Supply Voltage to Ground –0.5 to +7 V
VTERM(3) DC Switch Voltage Vs –0.5 to +7 V
VTERM(3) DC Input Voltage VIN –0.5 to +7 V
VAC AC Input Voltage (pulse width ≤ 20ns) –3 V
IOUT DC Output Current 120 mA
PMAX Maximum Power Dissipation (TA = 85°C) 0.5 W
TSTG Storage Temperature –65 to +150 °C
ABSOLUTE MAXIMUM RATINGS(1)
NOTE:
1 . Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. Vcc terminals.
3. All terminals except Vcc.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
I3
I2
I1
I0
Y
GND
VCC
S0
NC
ES1
S2
I4
I5
I6
I7
Select
ES2S1S0Y Function
H X X X Hi-Z Disable
LL L L I0S2 - S 0 = 0
LL L H I1S2 - S 0 = 1
LL H L I2S2 - S 0 = 2
LL H H I3S2 - S 0 = 3
LH L L I4S2 - S 0 = 4
LH L H I5S2 - S 0 = 5
LH H L I6S2 - S 0 = 6
LH H H I
7S2 - S 0 = 7
NOTE:
1 . H = HIGH Voltage Level
L = LOW Voltage Level
X = Don’t Care
Z = High-Impedence
Pins Typ. Max. (1) Unit
Control Inputs 4 5 pF
Quickswitch Channels Demux 5 7 pF
(Switch OFF) M ux 21 23
CAPACITANCE (TA = +25°C, f = 1MHz, VIN = 0V, VOUT = 0V)
NOTE:
1. This parameter is guaranteed but not production tested.
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IDTQS3251
HIGH-SPEED CMOS QUICKSWITCH 8:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
RON
(ohms)
VIN
(Volts)
TYPICAL ON RESIST ANCE vs VIN AT VCC = 5V
Symbol Parameter Test Conditions Min. Typ.(1) Max. Unit
VIH Input HIGH Level Guaranteed Logic HIGH for Control Pins 2 — — V
VIL Input LOW Level Guaranteed Logic LOW for Control Pins — — 0. 8 V
IIN Input LeakageCurrent (Control Inputs) 0V ≤ VIN ≤ VCC ——±1µA
IOZ Off-State Output Current (Hi-Z) 0V ≤ VOUT ≤ VCC ——±1µA
RON Switch ON Resistance(2) VCC = Min., VIN = 0V, ION = 30mA — 5 7 Ω
VCC = Min., VIN = 2.4V, ION =15mA — 10 15
VPPass Voltage(3) VIN = VCC = 5V, IOUT = -5µA 3.7 4 4.2 V
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, VCC = 5.0V ±5%
NOTES:
1. Typical values are at VCC = 5.0V, TA = 25°C.
2. RON is guaranteed but not production tested.
3. Pass Voltage is guaranteed but not production tested.
16
14
12
10
8
6
4
2
00.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
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INDUSTRIAL TEMPERATURE RANGE
IDTQS3251
HIGH-SPEED CMOS QUICKSWITCH 8:1 MUX/DEMUX
POWER SUPPLY CHARACTERISTICS
Symbol Parameter Test Conditions(1) Max. Unit
ICCQ Quiescent Power Supply Current VCC = Max., VIN = GND or Vcc, f = 0 3 µA
∆ICC Power Supply Current per Control Input HIGH (2) VCC = Max., VIN = 3.4V, f = 0 1.5 mA
ICCD Dynamic Power Supply Current per MHz(3) VCC = Max., I and Y pins open 0.25 mA/MHz
Control Inputs Toggling at 50% Duty Cycle
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TLL driven input (VIN = 3.4V, control inputs only). I and Y pins do not contribute to ∆Icc.
3. This current applies to the control inputs only and represents the current required to switch internal capacitance at the specified frequency. The I and Y inputs generate no significant
AC or DC currents as they transition. This parameter is guaranteed but not production tested.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
TA = -40°C to +85°C, VCC = 5.0V ± 5%;
CLOAD = 50pF, RLOAD = 500Ω unless otherwise noted.
Symbol Parameter Min. (1) Typ. Max. Unit
tPLH Data Propagation Delay (2,3) — — 0.25 ns
tPHL Ix to Y
tPZL Switch Turn-on Delay 0.5 — 6.6 ns
tPZH Sx to Y
tPZL Switch Turn-on Delay 0.5 — 6 ns
tPZH E to Y
tPLZ Switch Turn-off Delay (2) 0.5 — 6 ns
tPHZ E to Y, Sx to Y
NOTES:
1. Minimums are guaranteed but not production tested.
2.This parameter is guaranteed but not production tested.
3.The bus switch contributes no propagation delay other than the RC delay of the ON resistance of the switch and the load capacitance. The time constant for the switch alone
is of the order of 0.25ns for CL = 50pF. Since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very little propagation delay to
the system. Propagation delay of the bus switch, when used in a system, is determined by the driving circuit on the driving side of the switch and its interaction with the load
on the driven side.
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IDTQS3251
HIGH-SPEED CMOS QUICKSWITCH 8:1 MUX/DEMUX INDUSTRIAL TEMPERATURE RANGE
ORDERING INFORMATION
CORPORATE HEADQUARTERS for SALES: for Tech Support:
2975 Stender Way 800-345-7015 or 408-727-6116 logichelp@idt.com
Santa Clara, CA 95054 fax: 408-492-8674 (408) 654-6459
www.idt.com
IDTQS XXXXX XX
Package
Device Typ e
Small Outline IC
Quarter Size Outline Package
S1
Q
3251 High Speed CMOS Quickswitch 8:1 Mux/Demux
