
1
PS8149B 12/10/99
V
CC
BE
1
1
20
BE
2
2
19
1
B
0
1
A
0
3
18
2
A
3
2
B
3
4
17
1
B
1
1
A
1
5
16
2
A
2
2
B
2
6
15
1
B
2
1
A
2
7
14
2
A
1
2
B
1
8
13
1
B
3
1
A
3
9
12
2
A
0
2
B
0
10
11
GND
Product Description
Pericom Semiconductors PI3C series of logic circuits are produced
using the Companys advanced submicron CMOS technology,
achieving industry leading performance.
The PI3C3244 features a set of 2.5V or 3.3V 8-bit bus switches,
which is a pinout and function compatible with the P74FCT244T,
74F244, and 74ALS/AS/LS2448-bit drivers. Two enable signals
(BEn) turn the switches on similar to the enable signals of the 244.
The bus switch create no additional propagation delay or ground
bounce noise. It is very useful in switching signals that have high
bandwidth (>400 MHz).
Truth Table
(1)
Note:
1. H = High Voltage Level
L = Low Voltage Level
Logic Block Diagram
Product Pin Description
Pin Name
BEn
A07
B07
GND
V
CC
Description
Bus Enable Input (Active LOW)
Bus A
Bus B
Ground
Power
Product Pin Configuration
2.5V/3.3V, High Bandwidth, Hot Insertion,
8-Bit, 2-Port Bus Switch
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Product Features
Near zero propagation delay
High Bandwidth (>400 MHz)
Rail-to-Rail 3.3V or 2.5V Switching
5V I/O Tolerant
2.5V Supply Voltage Operation
Permits Hot Insertion
Pin compatible with 74 series 244 logic devices
Packages available:
20-pin 150 mil wide plastic QSOP (Q)
20-pin 173 mil wide plastic TSSOP (L)
20-Pin
L,Q
1
E
B
2
E
B
B
1
,
A
1
B
2
,
A
2
H
H
t
n
o
c
D
t
n
o
c
D
L
H
B
1
=
A
1
t
n
o
c
D
H
L
t
n
o
c
D
B
2
=
A
2
L
L
B
1
=
A
1
B
2
=
A
2
BE
2
BE
1
1B
1
1B
0
1A
1
1A
0
1B
1
1B
0
1A
3
1A
2
2B
1
2B
0
2A
1
2A
0
2B
3
2B
2
2A
3
2A
2