VS3257 / VS32257
Quad 2:1 Mux/Demux VSwitch
Applications
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5V to 3.3V translation in mixed-supply
environment
Hot-swap interface
Logic replacement
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Memory bank, video, & audio
swtiching
Power conservation
General Description
The VS3257 is a high-speed TTL–compatible Quad 2:1 multiplexer/demultiplexer. The VS3257 contains four
mux/demux channels, with a common path control (S) and active low enable (/E). The low ON resistance of
the VS3257 allows inputs to be connected to outputs, without adding propagation delay and without
generating additional signal noise. The VS32257 has 25Ω resistors in series with the switches to reduce
ground-bounce noise and signal reflection.
The VS3257 and VS32257 mux/demux switches are function and pinout compatible with QS3257 and
CBT3257 switches. They enable 5V to 3.3V translation when used with an external diode in the power supply
line. In addition, the high off-isolation in the ‘disable’ mode makes VS3257 and VS32257 ideal interface
elements for hot-swap applications.
Features
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Enhanced N-FET with no DC path to V
CC
or GND in normal operating signal voltage
range.
Low impedance bidirectional data flow:
5Ω (VS3257) and 25Ω (VS32257)
Pin-compatible with QS3257 and CBT3257
switches.
Near zero propagation delay
Zero added ground bounce or signal noise
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Break-before-make feature
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
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Figure 1. Functional Block Diagram
Figure 2. Pin Configuration
(All Pins Top View)
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
2001-04-12
Vaishali Semiconductor
Page 1
www.vaishali.com
747 Camden Avenue, Suite C Campbell CA 95008
MDSS-0009-01
Ph. 408.377.6060
Fax 408.377.6063
VAISH [ VAISHALI SEMICONDUCTOR ]
