2001-04-12 Page
1
MDSS-0002-02
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Applications
=
3.3v to 2.5V translation
=
2.5V to 1.8V translation
=
Hot Swapping
=
Bus switching
=
Clock gating
=
Logic replacement
General Description
The VS3V125 contains a set of four high-speed, low-resistance bus switches. Each bus switch is individually
controlled by LVTTL-compatible, active-low control input (/xOE). The low ON resistance of VS3V125 allows
inputs to be connected to outputs without adding propagation delay and without generating additional signal
noise.
The VS3V125 is designed for 3.3V to 2.5V, or 2.5V to 1.8V level translation, without any external
components. In addition, the high off-isolation between switch terminals in the `disable' mode, and the near-
zero propagation delay in the `on' state make the VS3V125 an ideal interface element 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 bidirectional data flow
=
Pin-compatible with CBTLV3215 switch
=
Zero added ground bounce or signal noise
=
LVTTL-compatible control signals
=
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
VS3V125
3.3V Quad Bus Switch with
Individual Active Low Enables
QSOP
NC
/1OE
1A
1Y
/2OE
2A
2Y
/4OE
4A
4Y
/3OE
3A
3Y
GND
V
CC
NC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
All Pins, Top View
NC= No Connect
1A
2A
3A
4A
1Y
2Y 3Y
4Y
/1OE
/2OE
/3OE
/4OE
VS3V125
2001-04-12 Page
2
MDSS-0002-002
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Table 1. Pin Description
Name I/O Description
1A 4A
I/O
Data Input or Output
1Y 4Y
I/O
Data Input or Output
/1OE - /4OE
I
Bus Switch Enable
Table 2. Function Table
/xOE Path Function
L
xA <-> xY
Enable switch
H
High Impedance
Disable switch
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.............................120mA
Maximum Power Dissipation.......................................0.5 Watts
Storage Temperature.......................................-65
o
C to +150
o
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.
Functional operation under absolute maximum rated conditions is not implied.
Table 4. Capacitance
T
A
= 25
o
C, f = 1MHz, V
IN
= 0V, V
OUT
= 0V
QSOP
Pins Typ
Max
Unit
Control Inputs
4
5
pF
VSwitch Channels ( Switch OFF )
5
7
pF
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 Parameter Conditions
Min
Typ
Max
Units
V
CC
Power supply voltage
2.3
3.6
V
V
IL
Low level input voltage
(Control inputs)
Vcc = 2.3 to 2.7
Vcc =2.7 to 3.6
0.7
0.8
V
V
IH
High level input voltage
(Control inputs)
Vcc = 2.3 to 2.7
Vcc = 2.7 to 3.6
1.7
2.0
V
T
A
Operating free-air temperature
-40
85
o
C
Note: All unused control inputs of the device must be held at Vcc or GND, to ensure proper device operation
VS3V125
2001-04-12 Page
3
MDSS-0002-002
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Table 6. Electrical Characteristics Over Recommended Operating Free-air Temperature Range
Symbol Parameter
Test
Conditions
Min
Typ
(1)
Max Units
Control Inputs
-1.5
V
IK
Clamp
Voltage
Switch I/O
V
CC
= Min., I
IK
= -18mA
-1.5
V
V
OH
Logic High Voltage
Switch I/O
V
IN
= V
CC
= 3.3V, I
OUT
= -100
A
V
IN
= V
CC
= 2.5V, I
OUT
= -100
A
2.3
1.5
2.7
2.0
V
I
I
Input Leakage
Current
Control Inputs
V
CC
= Max., V
I
= V
CC
or GND
1
A
Control Inputs
|
OFF
|
Power OFF Leakage
Current
Switch I/O
V
CC
= 0, V
I
or V
O
= V
CC
or GND.
1
A
|I
OZ
|
OFF State Leakage
Current
Switch I/O
V
CC
= Max., V
I/O
= V
CC
,
/xOE= V
CC
1
A
I
ODL
Switch I/O Drive
Current (Logic LOW)
V
CC
= 3.0V, V
IN
= 0, V
OUT
= 0.7V
50
mA
I
ODH
Switch I/O Drive
Current (Logic HIGH)
V
CC
= 3.0V, V
IN
= V
CC
, V
OUT
= 1.8V
-50
mA
V
CC
= 3.0V, V
IN
= 0, I
OUT
= 15mA
5
(2)
7
R
ON
Switch
ON
Resistance
(1)
V
CC
= 2.3V, V
IN
= 0, I
OUT
= 8mA
10
(3)
14
Notes:
1. 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.
2. Typical value is specified at V
CC
= 3.3V and T
A
= 25
o
C.
3. Typical value is specified at V
CC
= 2.5V and T
A
= 25
o
C.
Table 7. Power Supply Characteristics Over Recommended Operating Free-air Temperature Range
Symbol Parameter
Test
Conditions
(1)
Max
Units
I
CCQ
Quiescent Power Supply Current
V
CC
= Max.,/xOE = V
CC
or GND, f = 0
1
A
V
CC
= 3.6V, V
IN
= 3.0V, f = 0
I
CC
Power Supply Current per Input
High
(2)
V
CC
= 2.7V, V
IN
= 2.0V, f = 0
300
A
Q
CCD
Dynamic Power Supply Current
(3)
V
CC
= Max, Switch pins open, Control Inputs
toggling at 50% duty cycle
0.15 mA/MHz
Notes:
1. For conditions shown as Min or Max, use the appropriate values specified under Recommended Operating
Conditions.
2. Per control input. All other control inputs at GND. Switch I/O pins do not contribute to
I
CC
.
3. 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.
VS3V125
2001-04-12 Page
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MDSS-0002-002
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Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VOLTAGE TRANSLATION
V
OH
CHARACTERISTICS
Figure 4. 2.5V to 1.8V Translation
(T
A
+ 25
C)
Figure 5. V
OH
CHARACTERISTICS
(Vcc = 3.3V nominal)
Supply Voltage V
CC
(V)
(T
A
+ 25
C)
V
OH
(V)
Supply Voltage V
CC
(V)
(T
A
+ 25
C)
0
1.0
2.0
3.0
2.2
2.3
2.4
2.5
2.8
2.7
2.6
Figure 6. V
OH
CHARACTERISTICS
(Vcc = 2.5V nominal)
V
OH
(V)
0
1.0
2.0
3.0
2.9
3.1
3.3
3.6
3.7
3.0
3.2
3.4
3.5
3
1
2
3
1
V
OUT
(V)
Vcc=2.3V
Vcc=2.5V
Vcc=2.7V
3
Figure 3. 3.3V to 2.5V Translation
(T
A
+ 25
C)
V
OUT
(V)
1
2
4
0
1
2
3
4
Vcc=3.3V
Vcc=3.0V
Vcc=3.6V
V
IN
(V)
V
IN
(V)
2
VS3V125
2001-04-12 Page
5
MDSS-0002-002
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
Table 8. Switching Characteristics Over Operating Range 3.3V Supply Voltage
T
A
= -40
o
C to +85
o
C, V
CC
= 3.3V + 5%
C
LOAD
= 30pF, R
LOAD
= 500
unless otherwise stated.
Symbol Description
(1)
Min
(3)
Max Units
t
PLH
, t
PHL
Data Propagation Delay
(2,3)
through the switch
-
0.25
ns
t
PZH
, t
PZL
Switch Turn-on Delay, /xOE to xA or xY
1.5
6.5
ns
t
PLZ
, t
PHZ
Switch Turn-off Delay
(3)
,
/xOE to xA or xY
1.5
5.5
ns
Table 9. Switching Characteristics Over Operating Range 2.5V Supply Voltage
T
A
= -40
o
C to +85
o
C, V
CC
= 2.5V + 0.2V
C
LOAD
= 30pF, R
LOAD
= 500
unless otherwise stated.
Symbol Description
(1)
Min
(3)
Max
Units
t
PLH
, t
PHL
Data Propagation Delay
(2,3)
through the switch
ns
t
PZH
, t
PZL
Switch Turn-on Delay, , /xOE to xA or xY
ns
t
PLZ
, t
PHZ
Switch Turn-off Delay
(3)
,
/xOE to xA or xY
ns
Notes:
1. See test circuits and waveforms.
2. 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
of the order of 0.25ns for VS3V125. Since this time-constant is much smaller than rise/fall times of typical driving
signals, it adds very little propagation delay to the system.
3. This parameter is guaranteed, but not production tested.
Figure 5. AC Test Circuit and Switching Waveforms
AC Test Circuit - 3.3V Supply Voltage
Load Switch
Position
Pulse
Generator
DUT
V
IN
V
OUT
C
L
500
R
L
S
1
5 V
50
=
Coax to
Oscilloscope
50
450
TEST S1
t
PLH
, t
PHL
Open
t
PLZ
, t
PZL
Closed
t
PHZ
, t
PZH
Open
Input Conditions
1. Input voltage = 0 V to 3.0 V
2. t
r
= t
f
= 2.5ns (10% to 90%)
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