IDT QS3245

IDTQS3245
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
QUICKSWITCH® PRODUCTS
HIGH-SPEED CMOS
QUICKSWITCH
8-BIT BUS SWITCH
DESCRIPTION:
FEATURES:
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IDTQS3245
The QS3245 provides a set of eight high-speed CMOS TTL-compatible
bus switches in a pinout compatible with 74FCT245, 74F245, 74ALS/AS/
LS245 8-bit transceivers. The low ON resistance of the QS3245 allows
inputs to be connected to outputs without adding propagation delay and
without generating additional ground bounce noise. The Output Enable
(OE) signal turns the switches on similar to the OE signal of the 74’245.
QuickSwitch devices provide an order of magnitude faster speed than
conventional logic devices.
The QS3245 is characterized for operation at -40°C to +85°C.
Enhanced N channel FET with no inherent diode to Vcc
Ω bidirectional switches connect inputs to outputs
5Ω
Pin compatible with the 74F245, 74FCT245, and 74FCT245T
Low power CMOS proprietary technology
Zero propagation delay, zero ground bounce
Undershoot clamp diodes on all switch and control inputs
TTL-compatible control inputs
Available in SOIC, QSOP, and TSSOP packages
APPLICATIONS:
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Hot-swapping, hot-docking
Voltage translation (5V to 3.3V)
Power conservation
Capacitance reduction and isolation
Logic replacement (data processing)
Clock gating
Bus switching and isolation
FUNCTIONAL BLOCK DIAGRAM
A0
A1
A2
A3
A4
A5
A6
A7
B0
B1
B2
B3
B4
B5
B6
B7
OE
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
APRIL 2000
1
c
2000 Integrated Device Technology, Inc.
DSC-5753/1
IDTQS3245
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
NC
A0
1
2
ABSOLUTE MAXIMUM RATINGS(1)
20
19
VCC
OE
A1
3
18
A2
4
17
B1
A3
5
16
B2
A4
6
15
B3
A5
7
14
B4
A6
8
13
B5
A7
9
12
B6
GND
10
11
B7
B0
Symbol
Description
VTERM(2)
Max
Unit
VTERM(3)
Supply Voltage to Ground
–0.5 to +7
V
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
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.
CAPACITANCE
(TA = +25°C, f = 1.0MHZ, VIN = 0V, VOUT = 0V)
SOIC/ QSOP/ TSSOP
TOP VIEW
Pins
Typ.
Max.(1)
Unit
Control Pins
3
5
pF
5
7
pF
Quickswitch Channels (Switch OFF)
NOTE:
1. This parameter is measured at characterization but not tested.
PIN DESCRIPTION
Pin Names
Description
OE
Output Enable
Ax
Data I/Os
Bx
Data I/Os
FUNCTION TABLE(1)
OE
Outputs
H
Disconnected
L
Ax = Bx
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
2
IDTQS3245
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: TA = –40°C to +85°C, VCC = 5.0V ±5%
Symbol
Parameter
Test Conditions
Min.
Typ.(1)
Max.
Unit
2
—
—
V
VIH
Input HIGH Level
Guaranteed Logic HIGH for Control Pins
VIL
Input LOW Level
Guaranteed Logic LOW for Control Pins
—
—
0.8
V
IIN
Input LeakageCurrent (Control Inputs)
0V ≤ VIN ≤ VCC
—
—
±1
µA
IOZ
Off-State Output Current (Hi-Z)
0V ≤ VOUT ≤ VCC, Switches OFF
—
±0.001
±1
µA
RON
Switch ON Resistance
Pass Voltage(2)
—
—
3.7
5
10
4
7
15
4.2
Ω
VP
VCC = Min., VIN = 0V, ION = 30mA
VCC = Min., VIN = 2.4V, ION =15mA
VIN = VCC = 5V, IOUT = -5µA
NOTES:
1. Typical values are at VCC = 5.0V, TA = 25°C.
2. Pass Voltage is guaranteed but not production tested.
TYPICAL ON RESISTANCE vs VIN AT VCC = 5V
16
R ON
(ohms)
14
12
10
8
6
4
2
0
0.0
0.5
1.0
1.5
2.0
V IN
(Volts)
3
2.5
3.0
3.5
V
IDTQS3245
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
Test Conditions(1)
Parameter
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., A and B 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). A and B 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 A and B 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
tPLH
Data Propagation Delay (2,3)
tPHL
An to/from Bn
tPZL
Switch Turn-on Delay
tPZH
OE to Ax/Bx
tPLZ
Switch Turn-off Delay (2)
tPHZ
OE to Ax/Bx
Min. (1)
Typ.
Max.
Unit
—
—
0.25
ns
0.5
—
5.6
ns
0.5
—
4.5
ns
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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IDTQS3245
HIGH-SPEED CMOS QUICKSWITCH 8-BIT BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
ORDERING INFORMATION
IDTQS XXXXX
Device Type
XX
Package
X
Process
CORPORATE HEADQUARTERS
2975 Stender Way
Santa Clara, CA 95054
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Industrial (-40°C to +85°C)
SO
Q
PA
Small Outline IC
Quarter Size Outline Package
Thin Shrink Small Outline Package
3245
High Speed CMOS Quickswitch 8-Bit Bus Switch
for SALES:
800-345-7015 or 408-727-6116
fax: 408-492-8674
www.idt.com
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for Tech Support:
[email protected]
(408) 654-6459