VS3244 / VS32244
High Speed CMOS VSwitch
Dual 4-Bit Bus Switches
Applications
•=
•=
5V to 3.3V translation in mixed-supply environment
Hot-swap interface
•=
•=
Logic replacement
Bus isolation
General Description
The VS3244 and VS32244 are high-speed TTL–compatible dual 4-bit bus switches. The VS3244 contains
two banks of 4-bit switches, with one common active low enable (/G) per bank. The low ON resistance of the
VS3244 allows inputs to be connected to outputs, without adding propagation delay and without generating
additional signal noise. The VS32244 has 25Ω resistors in series with the switches to reduce ground-bounce
noise and signal reflection.
The VS3244 and VS32244 bus switches are function and pinout compatible with QS3244 and CBT3244
switches. They enable 5V to 3.3V translation when used with a diode in the power supply line. In addition,
the high off-isolation in the ‘disable’ mode makes VS3244 and VS32244 ideal interface elements for hot-swap
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:
5Ω (VS3244) and 25Ω (VS32244)
Pin-compatible with QS3244 and CBT3244
switches.
Near-zero propagation delay
•=
•=
•=
•=
•=
•=
Zero added ground bounce or signal noise
TTL-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- Available in 150-mil wide QSOP
package
•=
•=
•=
Figure 1. Functional Block Diagram
Figure 2. Pin Configuration
(All Pins Top View)
QSOP
/1G
1A1
1A2
1A3
1A4
1B1
1B2
1B3
1B4
/2G
2A1
2A2
2A3
2A4
2B1
2B2
2B3
2B4
/1G
1A1
2B4
1A2
2B3
1A3
2B2
1A4
2B1
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
/2G
1B1
2A4
1B2
2A3
1B3
2A2
1B4
2A1
2001-04-12
Vaishali Semiconductor
Page 1
www.vishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0008-02
Ph. 408.377.6060
Fax 408.377.6063
VS3244/VS32244
Table 1. Pin Description
Name
1A1 – 1A4
2A1 – 2A4
/1G, /2G
1B1 – 1B4
2B1 – 2B4
I
I/O
Enable Input
Data Output or Input
I/O
I/O
Description
Data Input or Output
Table 2. Function Table ( Each 4-bit bus switch)
Input
/nG
H
L
Hi Impedance
Switch Closed
Disable all switches
A port = B port
Path
Function
Table 3. Absolute Maximum Ratings
Supply Voltage to Ground………………………….…..-0.5V to +7.0V
DC Switch Voltage V
S
……………………….………….-0.5V to +7.0V
DC Input Voltage V
IN
………………………………… ...-0.5V to +7.0V
AC Input Voltage (Pulse Width < 20ns)……………….…………-3.0V
DC Output Sink Current per Switch Pin…………………...…..120 mA
Maximum Power Dissipation…………………………….…..0.5 Watts
Storage Temperature………………………………...-65 C to +150 C
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)
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.
Typ
4
5
Max
5
7
Unit
pF
pF
2001-04-12
Vaishali Semiconductor
Page 2
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0008-02
Ph. 408.377.6060
Fax 408.377.6063
VS3244/VS32244
Table 5. Recommended Operating Conditions
Symbol
V
CC
V
IL
V
IH
T
A
Parameter
Power supply voltage
Low level input voltage
High level input voltage
Operating free-air temperature
Conditions
Min
4.5
-0.5
2.0
-40
Typ
Max
5.5
0.8
5.5
85
V
V
V
o
Units
C
Table 6. Electrical Characteristics Over Recommended Operating Free-air Temperature Range
Symbol
V
IK
V
OH
Parameter
Clamp Voltage
Logic High Voltage
Control Input
Switch I/O
Switch I/O
Test Conditions
V
CC
= Min, I
IK
= -18 mA
V
IN
= V
CC
= 5V, I
OUT
= -5µA
V
CC
= 4.3V, V
N
= 5V,
I
OUT
= -5µA
Min
Typ
(1)
Max
-1.5
-1.5
Units
V
V
3.7
3.0
3.9
3.3
4.1
3.6
1
1
1
I
I
|
OFF
|
|I
OZ
|
I
ODL
I
ODH
R
ON
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
(2)
Resistance
Control Input
Control Input
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
V
CC
= Max, V
I/O
= V
CC
,
/1G, /2G = V
CC
VS3244
VS32244
VS3244
VS32244
VS3244
VS32244
20
5
28
-50
50
µA
µA
µA
mA
mA
mA
mA
V
CC
= Min, V
IN
= 0,
V
OUT
= 0.4V
V
CC
= Min, V
IN
= V
CC
,
V
OUT
= 2.4V
V
CC
= Min, V
IN
= 0,
I
OUT
= 30mA
7
40
Ω
Ω
Notes:
1.
2.
Typical values are specified at V
CC
= 5.0V and T
A
= 25
o
C.
R
ON
is measured by forcing specified current into the ‘output’ node of the switch with the ‘input’ node of the switch at the the
specified voltage
Table 7. Power Supply Characteristics Over Recommended Operating Free-air Temperature Range
Symbol
I
CCQ
∆I
CC
Q
CCD
Parameter
Quiescent Power Supply Current
Power Supply Current per Input High
(2)
(Control Input)
Dynamic Power Supply Current
(3)
Test Conditions
V
CC
= Max,
V
CC
= Max, V
IN
= 3.4V, f = 0
V
CC
= Max, Switch pins open,
(1)
Max
1
1.5
0.25
Units
µA
mA
mA/MHz
/1G, /2G = V
CC
or GND, f = 0
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 TTL-driven 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.
2001-04-12
Vaishali Semiconductor
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747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0008-02
Ph. 408.377.6060
Fax 408.377.6063
VS3244/VS32244
Figure 3. VOLTAGE TRANSLATION
5
4
Vout
(V)
3
2
1
0
0
VCC = 4.3V
Figure 4. VOH CHARACTERISTICS
4.5
VOH
Output Voltage
(V)
4.0
3.5
3.0
2.5
2.0
TA = 85°C
TA = 25°C
TA = - 40°C
1
2
3
Vin (V)
4
5
4.5
4.75
5.0
5.25
5.5
VCC – Supply Voltage (V)
Figure 5. Voltage Translation Application
V
CC
= 5V
1N4148
or equivalent
10K
V
CC
5V
DEVICE
I/O
VS3244
VS32244
/1G, /2G
I/O
3.3V
DEVICE
2001-04-12
Vaishali Semiconductor
Page 4
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0008-02
Ph. 408.377.6060
Fax 408.377.6063
VS3244/VS32244
Table 8. Switching Characteristics Over Operating Range
T
A
= -40 C to +85 C, V
CC
= 5.0V + 10%
C
LOAD
= 50pF, R
LOAD
= 500Ω unless otherwise stated.
o
o
Symbol
t
PLH
, t
PHL
t
PZH
, t
PZL
t
PLZ
, t
PHZ
Description
(1)
VS3245
Min
Max
(3)
VS32245
(3)
Min
Max
1.25
0.5
0.5
6.6
4.5
Units
ns
ns
ns
Data Propagation Delay
(2,3)
through the switch
Switch Turn-on Delay, /1G, /2G to A or B
Switch Turn-off Delay /1G, /2G to A or B
0.5
0.5
0.25
5.6
4.5
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
VS3244 and 1.25 ns for VS32244. 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 5. AC Test Circuit and Switching Waveforms
AC Test Circuit
Load Switch Position
TEST
t
PLH
, t
PHL
S
1
7V
500
Ω
R
L
450Ω
t
PLZ
, t
PZL
t
PHZ
, t
PZH
V
IN
DUT
V
OUT
Open
Closed
Open
S1
Pulse
Generator
50
Ω
Input Conditions
Input voltage = 0 V to 3.0 V
t
r
= t
f
= 2.5ns (10% to 90%)
C
L
50
Ω=
Coax to
Oscilloscope
2001-04-12
Vaishali Semiconductor
Page 5
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0008-02
Ph. 408.377.6060
Fax 408.377.6063
