VS3V257 / VS3V2257
High-speed 3.3V CMOS VSwitch
Quad 2:1 Mux/Demux
Applications
•=
•=
•=
3.3V to 2.5V translation
2.5V to 1.8V translation
Hot-Swapping
•=
•=
Logic replacement
Memory bank, video, and audio
switching
General Description
The VS3V257 is a high-speed LVTTL–compatible Quad 2:1 multiplexer/demultiplexer. The VS3V257
contains four mux/demux channels, with a common path control (S) and active low enable (/E). The low ON
resistance of the VS3V257 allows inputs to be connected to outputs, without adding propagation delay and
without generating additional signal noise. The VS3V2257 has 25Ω resistors in series with the switches to
reduce ground-bounce noise and signal reflection.
The VS3V257 and VS3V2257 are designed for 3.3V to 2.5V or 2.5V to 1.8V level translation, without any
external components. These switches also offer very high impedance between switch terminals in the
power-off or “disabled” state. This feature, combined with near-zero propagation delay in the “on” state,
makes VS3V257 and VS3V2257 ideal interface elements for hot-swapping applications.
Features
•=
Enhanced N-FET with no DC path to V
CC
or GND in normal operating signal voltage
range.
Low impedance switches connect inputs to
outputs with near-zero propagation delay:
5Ω (VS3V257) and 25Ω (VS3V2257)
Pin-compatible with 74LVC257 or
equivalent logic devices
Zero added ground bounce or signal noise
•=
•=
•=
•=
•=
•=
Break-before-make feature
Undershoot clamp diodes on all switch and
control pins
ESD rating >2000V (Human Body Model)
or >200V (Machine Model)
Latch-up current >100mA
Available in 150-mil wide QSOP package
•=
•=
•=
Figure 1. Functional Block Diagram
Figure 2. Pin Configuration
S
/E
Y
A
Y
B
Y
C
Y
D
I0
A
I1
A
I0
B
I1
B
I0
C
I1
C
I0
D
I1
D
S
I0
A
I1
A
Y
A
I0
B
I1
B
Y
B
GND
1
2
3
4
5
6
7
8
QSOP
16
15
14
13
12
11
10
9
V
CC
/E
I0
D
I1
D
Y
D
I0
C
I1
C
Y
C
(All Pins Top View)
2000-11-28
Vaishali Semiconductor
Page 1
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0001-01
Ph. 408.377.6060
Fax 408.377.6063
VS3V257/VS3V2257
Table 1. Pin Description
Name
I/O
Description
I0
X
, I1
X
S
/E
Y
A
- Y
D
I/O
I
I
I/O
Data Input or Output
Select Input
Enable Input
Data Output or Input
Table 2. Function Table
Inputs
Path
/E
H
L
L
S
X
L
H
Hi Impedance
IO
X
<-> Y
X
I1
X
<-> Y
X
Function
Disable all switches
Select 0
Select 1
Table 3. Absolute Maximum Ratings
Supply Voltage to Ground………………………….…..-0.5V to +4.6V
DC Switch Voltage V
S
……………………….………….-0.5V to +4.6V
DC Input Voltage V
IN
…………………………………...-0.5V to +4.6V
AC Input Voltage (Pulse Width < 20ns)……………….…………-3.0V
DC Output Sink Current per Switch Pin…………………...…..128 mA
Maximum Power Dissipation…………………………….…..0.5 Watts
Storage Temperature………………………………...-65 C to +150 C
Note
ABSOLUTE MAXIMUM CONTINUOUS RATINGS are those values beyond which damage to the device may occur. Exposure
to these conditions or conditions beyond those indicated may adversely affect device reliability. Correct functional operation
while operating in the absolute maximum rated conditions is not implied.
o
o
Table 4. Capacitance
T
A
= 25 C, f = 1 MHz, V
IN
= 0V, V
OUT
= 0V
o
QSOP
Pins
Control Inputs
VSwitch Channels
(Switch OFF)
Demux
Mux
Operation
Typ
4
5
7
Max
5
7
8
pF
pF
pF
Unit
Note
Capacitance is guaranteed, but not production tested. Total capacitance of a path, when the switch is closed, is the sum of the
switch terminal capacitances.
Table 5. Recommended Operating Conditions
Symbol
V
CC
V
IL
Parameter
Power supply voltage
Low level input voltage
(Control inputs)
Conditions
Min
2.3
Typ
Max
3.6
0.7
0.8
V
V
Units
Vcc = 2.3 to 2.7
Vcc =2.7 to 3.6
1.7
Vcc = 2.3 to 2.7
Vcc = 2.7 to 3.6
2.0
-40
V
IH
High level input voltage
(Control inputs)
V
T
A
2000-11-28
Operating free-air temperature
85
o
C
MDSS-0001-01
Note:
All unused control inputs of the device must be held at Vcc or GND, to ensure proper device operation
Page 2
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
Vaishali Semiconductor
Ph. 408.377.6060
Fax 408.377.6063
VS3V257/VS3V2257
Table 6. Electrical Characteristics Over Recommended Operating Free-air Temperature Range
Symbol
V
IK
Parameter
Clamp Voltage
Control Inputs
Switch I/O
Test Conditions
V
CC
= Min, I
IK
= -18 mA
Min
Typ
Max
-1.5
-1.5
Units
V
V
OH
Logic High Voltage
Switch I/O
V
IN
= V
CC
= 3.3V, I
OUT
= -5µA
V
IN
= V
CC
= 2.5V, I
OUT
= -5µA
2.1
1.4
2.6
1.9
1
1
V
I
I
|
OFF
|
Input Leakage Current
Power OFF Leakage
Current
OFF State Leakage
Current
Switch I/O Drive
Current (Logic LOW)
Switch I/O Drive
Current (Logic HIGH)
Switch ON
(1)
Resistance
Control Inputs
Control Inputs
Switch I/O
Switch I/O
V
CC
= Max, V
I
= V
CC
or GND
V
CC
= 0, V
I
or V
O
= V
CC
or GND
µA
µA
µA
|I
OZ
|
V
CC
= Max, V
I/O
= V
CC
,
/E = V
CC
1
I
ODL
V
CC
= 3.0V, V
IN
= 0,
V
OUT
= 1.5V
V
CC
= 3.0V, V
IN
= V
CC
,
V
OUT
= 1.5V
V
CC
= 3.0V, V
IN
= 0,
I
OUT
= 15mA
V
CC
= 2.3V, V
IN
= 0,
I
OUT
= 8mA
VS3V257
VS3V2257
VS3V257
VS3V2257
VS3V257
VS3V2257
VS3V257
VS3V2257
50
30
-20
-10
5
20
(2)
(2)
(3)
(3)
mA
mA
mA
mA
7
40
14
48
Ω
Ω
Ω
Ω
I
ODH
R
ON
28
10
23
35
Notes:
1.
2.
3.
R
ON
is measured by forcing specified current into the ‘output’ node of the switch with the ‘input’ node of the switch
at the specified voltage.
o
Typical value is specified at V
CC
= 3.3V and T
A
= 25 C.
o
Typical value is specified at V
CC
= 2.5V and T
A
= 25 C.
Table 7. Power Supply Characteristics Over Recommended Operating Free-air Temperature Range
Symbol
I
CCQ
∆I
CC
Parameter
Quiescent Power Supply Current
(2)
Test Conditions
V
CC
= Max,
V
CC
= 3.6V, V
IN
= 3.0V, f = 0
V
CC
= 2.7V, V
IN
= 2.1V, f = 0
V
CC
= Max, Switch pins open,
(1)
Max
1
300
Units
µA
µA
S, /E = V
CC
or GND, f = 0
Power Supply Current per Input High
(Control Inputs)
Dynamic Power Supply Current
(3)
Q
CCD
0.15
mA/MHz
Control Inputs toggling at 50% duty cycle
Notes:
1.
2.
3.
For conditions shown as Min or Max, use the appropriate values per
Recommended Operating Conditions.
Per control input. All other control inputs at GND. Switch I/O pins do not contribute to
∆ICC.
This parameter represents the average DC current resulting from the switching of internal nodes of the device at a
given frequency. The switch I/O pins make insignificant contribution to the dynamic power supply current of the
device. This parameter is guaranteed, but not production tested.
2000-11-28
Vaishali Semiconductor
Page 3
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0001-01
Ph. 408.377.6060
Fax 408.377.6063
VS3V257/VS3V2257
VOLTAGE TRANSLATION
4
3
3
Vcc=3.5V
Vcc=3.6V
Vcc=3.3V
Vcc=3.3V
Vcc=3.0V
Vcc=3.0V
2
2
V
OUT
(V)
V
OUT
(V)
Vcc=2.7V
Vcc=2.5V
Vcc=2.3V
1
1
0
0
1
2
3
V
IN
(V)
4
1
2
V
IN
(V)
3
Figure 3. 3.3V to 2.5V Translation
(T
A
+ 25
°C)
Figure 4. 2.5V to 1.8V Translation
(T
A
+ 25
°C)
V
OH
CHARACTERISTICS
3.0
3.0
2.0
2.0
V
OH
(V)
V
OH
(V)
1.0
1.0
0
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
0
2.2
2.3
2.4
2.5
2.6
2.7
2.8
Supply Voltage – V
CC
(V)
(T
A
+ 25
°C)
Supply Voltage – V
CC
(V)
(T
A
+ 25
°C)
Figure 5. V
OH
CHARACTERISTICS
(Vcc = 3.3V nominal)
Figure 6. V
OH
CHARACTERISTICS
(Vcc = 2.5V nominal)
2000-11-28
Vaishali Semiconductor
Page 4
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0001-01
Ph. 408.377.6060
Fax 408.377.6063
VS3V257/VS3V2257
Table 8. Switching Characteristics Over Operating Range – 3.3V Supply Voltage
T
A
= -40 C to +85 C, V
CC
= 3.3V + 0.3V
C
LOAD
= 30pF, R
LOAD
= 1kΩ unless otherwise stated.
o
o
Symbol
t
PLH
, t
PHL
t
PZH
, t
PZL
t
PZH
, t
PZL
t
PLZ
, t
PHZ
Description
(1)
VS3V257
Min
Max
(3)
VS3V2257
(3)
Min
Max
1.25
0.5
0.5
0.5
6.2
5.8
5.0
Units
ns
ns
ns
ns
Data Propagation Delay
(2,3)
through the switch
Switch Turn-on Delay, S to Y
X
, I0
X
, or I1
X
Switch Turn-on Delay, /E to Y
X
, I0
X
, or I1
X
Switch Turn-off Delay
(3)
,
S or /E to Y
X
, I0
X
, or I1
X
0.5
0.5
0.5
0.25
5.2
4.8
5.0
Table 9. Switching Characteristics Over Operating Range – 2.5V Supply Voltage
T
A
= -40 C to +85 C, V
CC
= 2.5V + 0.2V
C
LOAD
= 30pF, R
LOAD
= 1kΩ unless otherwise stated.
o
o
Symbol
t
PLH
, t
PHL
t
PZH
, t
PZL
t
PZH
, t
PZL
t
PLZ
, t
PHZ
Description
Data Propagation Delay
(2,3)
(1)
VS3V257
Min
Max
(3)
VS3V2257
(3)
Min
Max
Units
ns
ns
ns
ns
through the switch
Switch Turn-on Delay, S to Y
X
, I0
X
, or I1
X
Switch Turn-on Delay, /E to Y
X
, I0
X
, or I1
X
Switch Turn-off Delay
(3)
,
S or /E to Y
X
, I0
X
, or I1
X
Notes:
1.
2.
See test circuits and waveforms.
This parameter is the calculated theoretical RC time constant of ON-state resistance of the switch and the
specified load capacitance when driven by an ideal voltage source (zero source impedance). This time-constant is
on the order of 0.25 ns for VS3V257 and 1.25 ns for VS3V2257. Since this time-constant is much smaller than
rise/fall times of typical driving signals, it adds very little propagation delay to the system.
This parameter is guaranteed, but not production tested.
3.
Figure 7. AC Test Circuit and Switching Waveforms
AC Test Circuit
3.3V Supply Voltage
S
1
5V
1k
Ω
R
L
950
Ω
50
Ω
C
L
50
Ω=
Coax to
Oscilloscope
Load Switch Position
TEST
t
PLH
, t
PHL
t
PLZ
, t
PZL
t
PHZ
, t
PZH
Open
5V
GND
S1
R1
Pulse
Generator
V
IN
DUT
V
OUT
Input Conditions
Input voltage = 0 V to 3.0 V
t
r
= t
f
= 2.5ns (10% to 90%)
2000-11-28
Vaishali Semiconductor
Page 5
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0001-01
Ph. 408.377.6060
Fax 408.377.6063
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