1
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
NOVEMBER 1999
1999 Integrated Device Technology, Inc.
DSC-5579/1
c
IDTQS32XV245
INDUSTRIAL TEMPERATURE RANGE
FUNCTIONAL BLOCK DIAGRAM
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
FEATURES:
5
bidirectional switches connect inputs to outputs
Pin compatibility with QS3245
250ps propagation delay
Undershoot clamp diodes on all switch and control inputs
LVTTL-compatible control inputs
Available in 40-pin QVSOP package
APPLICATIONS:
3.3V to 2.5V Voltage translation
2.5V to 1.8V Voltage translation
PCI bus isolation hot swap
QUICKSWITCH
PRODUCTS
3.3V HIGH SPEED DOUBLE-
WIDTH BUS SWITCH
DESCRIPTION:
The QS32XV245 is a 16-bit high speed bus switch controlled by LVTTL-
compatible active low enable signal. When closed, the switches exhibit near zero
propagation delay without generating additional ground bounce or switching
noise.
The QS32XV245 is specially designed for direct interface between 3.3V and
2.5V devices without any external components. When operating from a 3.3V
supply, the logic high level at the switch output is clamped to 2.5V when the switch
input signal exceeds 2.5V. This device can be used for switching 2.5V buses
without signal attenuation. The ON resistance at 3.3V V
CC
is less than 5
typical,
providing near zero propagation delay through the switch. Absence of DC path
from switch I/O pins to V
CC
or ground makes QS32XV245 an ideal device for
hot swapping applications.
The QS32XV245 is characterized for operation from -40
C to +85C.
B
0
OE 1
A
0
B
1
A
1
B
2
A
2
B
3
A
3
B
4
A
4
B
5
A
5
B
6
A
6
B
7
A
7
B
8
OE 2
A
8
B
9
A
9
B
10
A
10
B
11
A
11
B
12
A
12
B
13
A
13
B
14
A
14
B
15
A
15
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
PIN CONFIGURATION
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
Z = High-Impedance
FUNCTION TABLE
(1)
CAPACITANCE
(T
A
= +25C, f = 1.0MH
Z
, V
IN
= 0V, V
OUT
= 0V)
NOTE:
1. This parameter is measured at characterization but not tested.
Pins
Typ.
Max.
(1)
Unit
Control Pins
4
6
pF
Quickswitch Channels (Switch OFF)
5
7
pF
Symbol
Description
Max
Unit
V
TERM
(2)
Supply Voltage to Ground
0.5 to +4.6
V
V
TERM
(3)
DC Switch Voltage Vs
0.5 to +4.6
V
V
TERM
(3)
DC Input Voltage V
IN
0.5 to +4.6
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
= 85C)
0.6
W
T
STG
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.
QVSOP
TOP VIEW
PIN DESCRIPTION
Pin Names
Description
OE
Output Enable
An, Bn
Data I/Os
OE1
OE2
A
0
- A
7
A
8
- A
15
Function
H
H
Z
Z
Disconnect
L
H
B
0
- B
7
Z
Connect
H
L
Z
B
8
- B
15
Connect
L
L
B
0
- B
7
B
8
- B
15
Connect
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
NC
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
G ND
NC
A
8
A
9
A
10
A
11
A
12
A
13
A
14
A
15
G ND
V
C C
O E1
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
O E2
B
8
B
9
B
10
B
11
B
12
B
13
B
14
B
15
V
C C
3
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Level
Guaranteed Logic HIGH for Control Pins
2
--
--
V
V
IL
Input LOW Level
Guaranteed Logic LOW for Control Pins
--
--
0.8
V
I
IN
Input LeakageCurrent (Control Inputs)
0V
V
IN
V
CC
--
--
1
A
I
OZ
Off-State Output Current (Hi-Z)
0V
V
OUT
V
CC
, Switches OFF
--
0.001
1
A
V
CC
= Min., V
IN
= 0V, I
ON
= 8mA
--
5
7
R
ON
Switch ON Resistance
V
CC
= Min., V
IN
= 1.7V, I
ON
= 8mA
--
15
20
V
CC
= 2.3V, V
IN
= 0V, I
ON
= 8mA
--
7
--
V
CC
= 2.3V, V
IN
= 1.3V, I
ON
= 8mA
--
25
--
V
P
Pass Voltage
(2)
V
IN
= V
CC
= 3.3V, I
OUT
= -5
A
2.5
2.7
2.9
V
V
IN
= V
CC
= 2.5V, I
OUT
= -5
A
--
1.8
--
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= 40C to +85C, V
CC
= 3.3V 0.3V
NOTES:
1. Typical values are at V
CC
= 3.3V, T
A
= 25C.
2. Pass Voltage is guaranteed but not production tested.
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
6
A
I
CC
Power Supply Current per Control Input HIGH
(2)
V
CC
= Max., V
IN
= 3.4V, f = 0
50
A
I
CCD
Dynamic Power Supply Current per MHz
(3)
V
CC
= Max., A and B pins open
0.15
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 (V
IN
= 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.
4
INDUSTRIAL TEMPERATURE RANGE
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
T
A
= -40C to +85C,
V
CC
= 3.3V 0.3V
C
LOAD
= 50pF, R
LOAD
= 500
unless otherwise noted.
Symbol
Parameter
Min.
(1)
Typ.
Max.
Unit
t
PLH
Data Propagation Delay
(2,3)
--
--
0.25
ns
t
PHL
An to/from Bn
t
PZL
Switch Turn-on Delay
0.5
--
6.5
ns
t
PZH
OEn to An/Bn
t
PLZ
Switch Turn-off Delay
(2)
0.5
--
4
ns
t
PHZ
OEn to An/Bn
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 C
L
= 30pF. 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.
14
0.5
1
1.5
2
2.5
V
IN
- (Volts)
R
O
N
-
(
o
h
m
s
)
12
10
8
6
4
2
0
0.
16
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 3.3V
5
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
2 5 0
2 0 0
1 5 0
1 0 0
5 0
0
0
0 .5
1
1 .5
2
V
O U T
( V o lts )
I
O
s
-
(
m
A
)
-2 5 0
-2 0 0
-1 5 0
-1 0 0
-5 0
1
2
3
4
V
O U T
(V o lts )
I
O
s
-
(
m
A
)
-3 0 0
OUTPUT VI CHARACTERISTICS
Outputs Low Characteristic
Outputs High Characteristic
3
2.5
2
1.5
2.2
2.4
2.7
3
3.3
3.6
V
CC
(V)
V
O
U
T
-
(
V
o
l
t
s
)
V
O UT
= 2.5V @ V
C C
= 3.3V
V
OUT
= 1.8V @ V
C C
= 2.5V
PASS VOLTAGE vs V
CC
6
INDUSTRIAL TEMPERATURE RANGE
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
QS32XV245
2.5V
2.5V
3.3V
2.5V
3.3V
Q S32XV245
1.8V
1.8V
2.5V
1.8V
2.5V
V
IN
2.5V
V
O U T
3.3V
Supply
0V
3.3V
Sw
i
t
c
h
O
u
t
put
Switch Input
V
IN
1.8V
2.5V
Supply
0V
2.5V
V
O U T
Sw
i
t
c
h
O
u
t
pu
t
Switch Input
2.5V TO 1.8V VOLTAGE TRANSLATION
3.3V TO 2.5V VOLTAGE TRANSLATION
7
IDTQS32XV245
3.3V HIGH SPEED DOUBLE-WIDTH BUS SWITCH
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
ID TQ S
X XXXX
X X
X
P ackage
Process
D evice Type
B lank
32XV245
Industrial (-40C to +85C )
3.3V High S peed D ouble-W idth B us Sw itch
Q2
40-Pin QVS OP
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