VS3345 / VS32345
High Speed CMOS VSwitch
8-Bit Bus Switches with
Active High & Low Enables
Applications
•=
•=
5V to 3.3V translation in mixed-supply environment
Hot-swap interface
•=
•=
Logic replacement
Bus isolation
General Description
The VS3345 and VS32345 are high-speed TTL–compatible 8-bit bus switches. The VS3345 contains eight high-speed
bus switches, with common active low (/OE) and active high (OE) enables. The low ON resistance of the VS3345
allows inputs to be connected to outputs, without adding propagation delay and without generating additional signal
noise. The VS32345 has 25Ω resistors in series with the switches to reduce ground-bounce noise and signal reflection.
The VS3345 and VS32345 bus switches switches 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 VS3345 and VS32345 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 (VS3345) and 25Ω (VS32345)
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 in 150-mil wide QSOP package
•=
•=
•=
Figure 1. Functional Block Diagram
Figure 2. Pin Configuration
(All Pins Top View)
QSOP
A0
A1
A2
A3
A4
A5
A6
A7
OE
A0
A1
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
/OE
B0
B1
B2
B3
B4
B5
B6
B7
OE
/OE
A2
A3
A4
A5
A6
A7
B0
B1
B2
B3
B4
B5
B6
B7
GND
2001-04-12
Vaishali Semiconductor
Page 1
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0010-01
Ph. 408.377.6060
Fax 408.377.6063
VS3345/VS32345
Table 1. Pin Description
Name
A
0
- A
7
/OE
OE
B
0
– B
7
I
I
I/O
I/O
I/O
Description
Data Input or Output
Active Low Enable Input
Active High Enable Input
Data Output or Input
Table 2. Function Table
Input
/OE
H
X
L
OE
X
L
H
Hi Impedance
Hi Impedance
A
n
<-> B
n
Disable all switches
Disable all switches
A
n
= B
n
Path
Function
Note:
X = Don’t care
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
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 whiled 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-0010-01
Ph. 408.377.6060
Fax 408.377.6063
VS3345/VS32345
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
Parameter
Clamp Voltage
Control Input
Switch I/O
Test Conditions
V
CC
= Min, I
IK
= -18 mA
Min
Typ
(1)
Max
-1.5
-1.5
Units
V
V
OH
Logic High Voltage
Switch I/O
V
IN
= V
CC
= 5V, I
OUT
= -5µA
V
CC
= 4.3V, V
IN
= 5V,
I
OUT
= -5µA
3.7
3.0
3.9
3.3
4.1
3.6
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
(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
,
/OE = V
CC
or OE = GND
µA
µA
µA
|I
OZ
|
1
I
ODL
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
VS3345
VS32345
VS3345
VS32345
VS3345
VS32345
50
mA
mA
I
ODH
-50
mA
mA
5
7
40
Ω
Ω
R
ON
20
28
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
/OE, OE = 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
Page 3
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0010-01
Ph. 408.377.6060
Fax 408.377.6063
VS3345/VS32345
Figure 3. VOLTAGE TRANSLATION
5
4
Vout
(V)
3
2
1
0
0
VCC = 4.3V
Figure 4. VOH CHARACTERISTICS
4.5
4.0
3.5
VOH
Output Voltage
(V)
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
I/O
5V
DEVICE
10k
OE
/OE
VS3345
VS32345
I/O
3.3V
DEVICE
2001-04-12
Vaishali Semiconductor
Page 4
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0010-01
Ph. 408.377.6060
Fax 408.377.6063
VS3345/VS32345
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: /OE, OE to A
n
, B
n
Switch Turn-off Delay: /OE, OE to A
n
, B
n
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
VS3345 and 1.25 ns for VS32345. 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 6. 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-0010-01
Ph. 408.377.6060
Fax 408.377.6063
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
