1
IDTQS3S257
HIGH-SPEED CMOS SYNCHROSWITCH QUAD 2:1 MUX
INDUSTRIAL TEMPERATURE RANGE
NOVEMBER 1999
1999 Integrated Device Technology, Inc.
DSC-5536/-
c
IDTQS3S257
INDUSTRIAL TEMPERATURE RANGE
QUICKSWITCH
PRODUCTS
HIGH-SPEED CMOS
SYNCHROSWITCHTM
QUAD 2:1 MUX/DEMUX
DESCRIPTION:
The QS3S257 is a high-speed CMOS Quad 2:1 multiplexer/demultiplexer.
Port selection and connection, controlled by SEL signals, can be either
asynchronous or synchronous. In the synchronous mode, the A or B port
to Y port connection is updated on the rising edge of the input clock CLK.
Once the port-to-port connection is made, data flow can be bi-directional with
a typical 250ps propagation delay through the switch. Clock Enable,
overriding Asynchronous Enable, and Asynchronous Select controls
provide additional design flexibility. Synchronous controls eases timing
constraints in many high speed data mux/demux applications, such as bank
interleaving. The QS3S257 can also be used in 5V to 3.3V translation.
QuickSwitch Mux/Demux devices provide an order of magnitude faster
speed than equivalent logic devices.
The QS3S257 is characterized for operation at -40C to +85C.
SEL
CLK
CLKE N
OE
SYNC
Y
0
Y
1
Y
2
Y
3
A
0
B
0
A
1
A
2
A
3
B
1
B
2
B
3
CONTROL
LOGIC
FUNCTIONAL BLOCK DIAGRAM
FEATURES:
-
Enhanced N channel FET with no inherent diode to Vcc
-
Bidirectional signal flow
-
Flow-through pinout
-
Zero propagation delay, zero ground bounce
-
4 banks of 2:1 Mux/Demux
-
Port select synchronous to the clock
-
Clock enable and Asynchronous switch enable
-
"Bus-hold" terminators on the Demux side
-
Undershoot clamp diodes on all switch and control pins
-
Asynchronous SEL option
-
Break-before-make feature
-
Available in 20-pin QSOP Package
-
Bus-hold eliminates floating bus lines and reduces static power
consumption
APPLICATIONS:
-
Video, audio, graphics switching, muxing
-
Bus funneling
-
Voltage translation
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS3S257
HIGH-SPEED CMOS SYNCHROSWITCH QUAD 2:1 MUX
PIN CONFIGURATION
NC
A
0
A
1
B
0
B
1
GND
2
3
4
5
6
7
8
13
14
15
16
17
18
19
20
1
9
10
11
12
Vcc
CLKEN
CLK
SYNC
OE
SEL
Y
0
Y
1
SO20-8
B
2
B
3
A
2
A
3
Y
2
Y
3
QSOP
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
Description
Max.
Unit
V
TERM(2)
Supply Voltage to Ground
0.5 to +7
V
V
TERM(3)
DC Switch Voltage V
S
0.5 to +7
V
V
TERM(3)
DC Input Voltage V
IN
0.5 to +7
V
V
AC
AC Input Voltage (pulse width
20ns)
-3
V
I
OUT
DC Output Current
120
mA
P
MAX
Maximum Power Dissipation (T
A
= 85
C)
.82
W
T
STG
Storage Temperature
65 to +150
C
NOTES:
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
(T
A
= +25
O
C, f = 1.0MHz, V
IN
= 0V, V
OUT
= 0V)
Pins
Typ.
Max.
(1)
Unit
Control Inputs
4
5
pF
Quickswitch Channels
Demux
5
7
pF
(Switch OFF)
Mux
7
9
pF
NOTE:
1. This parameter is guaranteed but not production tested.
PIN DESCRIPTION
Pin Names
I/O
Description
A
0
- A
3
I/O
Demux Port A
B
0
- B
3
I/O
Demux Port B
Y
0
- Y
3
I/O
Mux Port Y
SEL
I
Select Input
CLK
I
Clock
CLKEN
I
Clock Enable
OE
I
Output Enable
SYNC
I
Synchronous Enable
3
IDTQS3S257
HIGH-SPEED CMOS SYNCHROSWITCH QUAD 2:1 MUX
INDUSTRIAL TEMPERATURE RANGE
1
2:1
M U X
0
SE L
C LKEN
C LK
SYN C
O E
0
2:1
M U X
1
D
Q
To Port B Sw itches
To Port A Sw itches
CONTROL LOGIC
FUNCTION TABLE
(1)
Control Inputs
Port Status
Function
SYNC
OE
CLKn
CLKEN
SEL
Y
0
Y
1
Y
2
Y
3
L
L
L
L
A
0
A
1
A
2
A
3
Select Port A
L
L
L
H
B
0
B
1
B
2
B
3
Select Port B
L
H
L
X
No change in Mux connection
Hold Previous Data
(2)
(Switch OFF)
L
L
H
X
No change in Mux connection
Hold Previous Mux connection
(3)
(Switch ON)
L
H
H
X
No change in Mux connection
Hold Previous Data
(4)
(Switch OFF)
H
L
X
X
L
A
0
A
1
A
2
A
3
Select Port A
H
L
X
X
H
B
0
B
1
B
2
B
3
Select Port B
H
H
X
X
X
No change in Mux connection
Hold Previous Data
(2)
(Switch OFF)
NOTES:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don't Care
= Low-to-High Transition
2. Mux switches are turned off and the terminators (last value latches) hold the previous data state. The port connection can be changed by the SEL
input.
3. The contents of the "Mux select register" are unchanged and the previous Mux connection is unchanged. The output (Mux port) data state will
depend on the present data state of the input (Demux port).
4. The contents of the "Mux select register" are unchanged and the last value latches hold the previous data state.
4
INDUSTRIAL TEMPERATURE RANGE
IDTQS3S257
HIGH-SPEED CMOS SYNCHROSWITCH QUAD 2:1 MUX
R
ON
(ohms)
V
IN
(Volts)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
2
4
6
8
10
12
14
16
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= -40C to +85C, V
CC
= 5.0V 10%
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH for Control Pins
2
--
--
V
V
IL
Input LOW Voltage
Guaranteed Logic LOW for Control Pins
--
--
0.8
V
I
IN
Input Leakage Current (Control Inputs)
0V
V
IN
Vcc
--
0.1
1
A
R
ON
Switch On Resistance
(2)
Vcc = Min., V
IN
= 0V
,
I
ON
= 30mA
--
7
9
Vcc = Min., V
IN
= 2.4V
,
I
ON
= 15mA
--
10
13
V
P
Pass Voltage
(3)
V
IN
= Vcc = 5V
,
I
OUT
= -5
A
3.7
4
4.2
V
NOTES:
1. Typical values are at V
CC
= 5.0V, T
A
= 25C.
2. R
ON
guaranteed but not production tested.
3. Pass Voltage guaranteed but not production tested.
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 5V
5
IDTQS3S257
HIGH-SPEED CMOS SYNCHROSWITCH QUAD 2:1 MUX
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Max.
Unit
I
CCQ
Quiescent Power Supply Current
V
CC
= Max., V
IN
= GND or Vcc, f = 0
3
A
I
CC
Power Supply Current per Control Input HIGH
(2)
V
CC
= Max., V
IN
= 3.4V, f = 0
1.5
mA
I
CCD
Dynamic Power Supply Current per MHz
(3)
V
CC
= Max., A/B and Y pins open
Control Input Toggling at 50% Duty Cycle
0.25
mA/MHz
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TLL driven input (V
IN
= 3.4V, control inputs only). A/B 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 A/B
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
T
A
= -40C to +85C, V
CC
= 5.0V 10%
C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
Symbol
Parameter
Min.
Typ.
Max.
Unit
t
PLH
t
PHL
Data Propagation Delays
(1,2)
A/B to Y, Y to A/B
--
0.25
--
ns
t
SEC
Clock Enable to Clock Setup Time
3
--
--
ns
t
HEC
Clock Enable to Clock Hold Time
0
--
--
ns
t
CSO
Clock to A,B Switch Turn-On Delay
(3)
0.5
--
7
ns
t
ASO
Asynchronous Select to A,B Switch Turn-On Delay
(3)
0.5
--
7
ns
t
W
Clock Pulse Width (High)
3
--
--
ns
t
SCS
SEL to Clock Setup Time
3
--
--
ns
t
HCS
SEL to Clock Hold Time
0
--
--
ns
t
PZL
t
PZH
Asynchronous Enable to Switch Turn-On Delay
(3)
1.5
--
5.2
ns
t
PLZ
t
PHZ
Asynchronous Enable to Switch Turn-Off Delay
(1,3)
1.5
--
4.8
ns
NOTES:
1. This parameter is guaranteed but not production tested.
2. 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 C
L
= 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.
3. Minimums guaranteed but not production tested.
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