VAISH VS3345

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
•=
Logic replacement
•=
Hot-swap interface
•=
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 VCC
or GND in normal operating signal voltage
range.
•=
TTL-compatible control signals
•=
Undershoot clamp diodes on all switch and
control pins
•=
Low impedance bidirectional data flow:
5Ω (VS3345) and 25Ω (VS32345)
•=
ESD rating >2000V (Human Body Model)
or >200V (Machine Model)
•=
Near-zero propagation delay
•=
Latch-up current >100mA
•=
Zero added ground bounce or signal noise
•=
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
/OE
B0
2001-04-12
B1
B2
B3
B4
B5
B6
B7
VCC
OE
1
20
A0
2
19
/OE
A1
3
18
B0
A2
4
17
B1
A3
5
16
B2
A4
6
15
B3
A5
7
14
B4
A6
8
13
B5
A7
9
12
B6
10
11
B7
GND
Page 1
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VS3345/VS32345
Table 1. Pin Description
Name
I/O
Description
A0 - A7
I/O
Data Input or Output
/OE
I
Active Low Enable Input
OE
I
Active High Enable Input
B0 – B7
I/O
Data Output or Input
Table 2. Function Table
Input
/OE
Path
Function
OE
H
X
Hi Impedance
Disable all switches
X
L
Hi Impedance
Disable all switches
L
H
An <-> Bn
An = Bn
Note: X = Don’t care
Table 3. Absolute Maximum Ratings
Supply Voltage to Ground………………………….…..-0.5V to +7.0V
DC Switch Voltage VS……………………….………….-0.5V to +7.0V
DC Input Voltage VIN………………………………… ...-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
o
o
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.
Table 4. Capacitance
o
TA = 25 C, f = 1 MHz, VIN = 0V, VOUT = 0V
QSOP
Pins
Typ
Max
Unit
Control Inputs
4
5
pF
VSwitch Channels
5
7
pF
(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.
2001-04-12
Page 2
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VS3345/VS32345
Table 5. Recommended Operating Conditions
Symbol
Parameter
Conditions
Min
Typ
Max
Units
VCC
Power supply voltage
4.5
5.5
V
VIL
Low level input voltage
-0.5
0.8
V
VIH
High level input voltage
2.0
5.5
V
TA
Operating free-air temperature
-40
85
o
C
Table 6. Electrical Characteristics Over Recommended Operating Free-air Temperature Range
Symbol
VIK
Parameter
Clamp Voltage
Test Conditions
Control Input
Min
Typ
(1)
VCC = Min, IIK = -18 mA
Switch I/O
VOH
Logic High Voltage
Max
Units
-1.5
V
-1.5
Switch I/O
VIN = VCC = 5V, IOUT = -5µA
3.7
3.9
4.1
VCC = 4.3V, VIN = 5V,
3.0
3.3
3.6
V
IOUT = -5µA
II
Input Leakage
Current
Control Input
VCC = Max, VI = VCC or GND
1
µA
|OFF|
Power OFF Leakage
Current
Control Input
VCC = 0,
1
µA
Switch I/O
VI or VO = VCC or GND
OFF State Leakage
Current
Switch I/O
VCC = Max, VI/O = VCC,
1
µA
Switch I/O Drive
Current (Logic LOW)
VCC = Min, VIN = 0,
VS3345
VOUT = 0.4V
VS32345
Switch I/O Drive
Current (Logic HIGH)
VCC = Min, VIN = VCC,
VS3345
VOUT = 2.4V
VS32345
VCC = Min, VIN = 0,
VS3345
IOUT = 30mA
VS32345
|IOZ|
IODL
IODH
RON
Switch ON
(2)
Resistance
/OE = VCC or OE = GND
50
mA
mA
-50
mA
mA
20
5
7
Ω
28
40
Ω
Notes:
1.
2
Typical values are specified at VCC = 5.0V and TA = 25oC.
RON 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
Parameter
Test Conditions
Max
Units
1
µA
VCC = Max, VIN = 3.4V, f = 0
1.5
mA
VCC = Max, Switch pins open,
0.25
mA/MHz
ICCQ
Quiescent Power Supply Current
VCC = Max,
∆ICC
Power Supply Current per Input High
(2)
(Control Input)
QCCD
Dynamic Power Supply Current
(3)
(1)
/OE, OE = VCC 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
Page 3
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VS3345/VS32345
Figure 3. VOLTAGE TRANSLATION
5
4.5
4
4.0
Vout
(V)
Figure 4. VOH CHARACTERISTICS
VCC = 4.3V
3
2
3.5
VOH
Output Voltage
(V)
3.0
1
2.5
TA = 85°C
TA = 25°C
TA = - 40°C
2.0
0
1
0
2
3
Vin (V)
4
4.5
5
4.75
5.0
5.25
5.5
VCC – Supply Voltage (V)
Figure 5. Voltage Translation Application
VCC = 5V
1N4148
or equivalent
10k
VCC
I/O
5V
DEVICE
I/O
VS3345
VS32345
10k
3.3V
DEVICE
OE
/OE
2001-04-12
Page 4
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VS3345/VS32345
Table 8. Switching Characteristics Over Operating Range
o
o
TA = -40 C to +85 C, VCC = 5.0V + 10%
CLOAD = 50pF, RLOAD = 500Ω unless otherwise stated.
Symbol
Description
(2,3)
(1)
Min
through the switch
(3)
VS3245
Max
VS32245
(3)
Min
Max
0.25
1.25
ns
Units
tPLH, tPHL
Data Propagation Delay
tPZH, tPZL
Switch Turn-on Delay: /OE, OE to An, Bn
0.5
5.6
0.5
6.6
ns
tPLZ, tPHZ
Switch Turn-off Delay: /OE, OE to An, Bn
0.5
4.5
0.5
4.5
ns
Notes:
1.
2.
3.
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.
Figure 6. AC Test Circuit and Switching Waveforms
Load Switch Position
AC Test Circuit
TEST
S1
7V
VIN
Pulse
Generator
VOUT
RL
450Ω
2001-04-12
CL
tPLH, tPHL
Open
tPLZ, tPZL
Closed
tPHZ, tPZH
Open
500Ω
DUT
50Ω
S1
50Ω=Coax to
Oscilloscope
Input Conditions
Input voltage = 0 V to 3.0 V
tr = tf = 2.5ns (10% to 90%)
Page 5
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063
VS3345/VS32345
Switching Waveforms
3.0 V
Input
1.5 V
0V
tPLH
tPHL
VOH
Switch Output
1.5 V
VOL
Propagation Delay
3.0 V
1.5 V
Control Input
0V
tPZH
tPHZ
VOH
0.3 V
Switch Output
(Switch Input = 3.0 V)
1.5 V
0V
tPLZ
Switch Output
(Switch Input = 0 V)
tPZL
0.3 V
Switch ON
Switch OFF
3.5 V
1.5 V
VOL
Switch ON
Enable and Disable Times
Ordering Information
Part Number
VS3345Q
VS32345Q
2001-04-12
No. of Pins
20
20
Package
QSOP
QSOP
Temperature
-40°C to +85°C
-40°C to +85°C
Page 6
MDSS-0010-01
www.vaishali.com
Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063