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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
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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
Description
BEn
Bus Enable Input (Active LOW)
A07
Bus A
B07
Bus B
GND
Ground
V
CC
Power
Product Pin Configuration
PI3C3244
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
c
e
n
n
o
c
si
D
t
c
e
n
n
o
c
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D
L
H
B
1
=
A
1
t
c
e
n
n
o
c
si
D
H
L
t
c
e
n
n
o
c
si
D
B
2
=
A
2
L
L
B
1
=
A
1
B
2
=
A
2
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PS8149B 12/10/99
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PI3C3244
2.5V/3.3V, High Bandwidth,
Hot Insertion, 8-Bit, 2-Port Bus Switch
DC Electrical Characteristics
(Over Operating Range, T
A
= 40C to +85C, V
CC
= 3.3V 10%)
Parameters Description
Test Conditions
(1)
Min. Typ.
(2)
Max.
Units
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH Level
2.0
V
IL
Input LOW Voltage
Guaranteed Logic LOW Level
0.5
0.8
I
IH
Input HIGH Current
V
CC
= Max., V
IN
= V
CC
1
I
IL
Input LOW Current
V
CC
= Max., V
IN
= GND
1
A
I
OZH
High Impedance Output Current
0
A, B
V
CC
1
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18mA
0.73
1.2
V
R
ON
Switch On Resistance
(4)
V
CC
= Min., V
IN
= 0.0V,
I
ON
= 48mA or 64mA
5
7
V
CC
= Min., V
IN
= 2.4V,
I
ON
= 15mA
8
15
Parameters
(5)
Description
Test Conditions
Typ.
Units
C
IN
Input Capacitance
V
IN
= 0V
3.5
C
OFF
A/B Capacitance, Switch Off
V
IN
= 0V
5.0
pF
C
ON
A/B Capacitance, Switch On
V
IN
= 0V
10.0
Storage Temperature..................................................... 65C to +150C
Ambient Temperature with Power Applied ....................... 40C to +85C
Supply Voltage to Ground Potential .................................. 0.5V to +4.6V
DC Input Voltage ............................................................... 0.5V to +5.5V
DC Output Current ......................................................................... 120mA
Power Dissipation ............................................................................. 0.5W
Note:
Stresses greater than those listed under MAXIMUM
RATINGS may cause permanent damage to the device.
This is a stress rating only and functional operation of the
device at these or any other conditions above those
indicated in the operational sections of this specification
is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 3.3V, T
A
= 25C ambient and maximum loading.
3. Not more than one output should be shorted at one time. Duration of the test should not exceed one second.
4. Measured by the voltage drop between A and B pin at indicated current through the switch. ON resistance is determined
by the lower of the voltages on the two (A,B) pins.
5. This parameter is determined by device characterization but is not production tested.
V
Maximum Ratings
(Above which the useful life may be impaired. For user guidelines, not tested.)
Capacitance
(T
A
= 25C, f = 1 MHz)
PI3C3244
2.5V/3.3V, High Bandwidth,
Hot Insertion, 8-Bit, 2-Port Bus Switch
3
PS8149B 12/10/99
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PI3C3244
Com.
Parameters Description
Conditions
(1)
Min.
Max. Units
t
PLH
Propagation Delay
(2,3)
C
L
= 50 pF,
0.25
t
PHL
Ax to Bx
R
L
= 500
t
PZH
Bus Enable Time
1.5
6.5
ns
t
PZL
BE to Ax or Bx
C
L
= 50 pF,
t
PHZ
Bus Disable Time
R
L
= 500
,
1.5
5.5
t
PLZ
BE to Ax or Bx
R = 500
Power Supply Characteristics
Parameters Description
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Units
I
CC
Quiescent Power
V
CC
= Max.
V
IN
= GND or V
CC
260
500
Supply Current
I
CC
Supply Current per
V
CC
= Max.
V
IN
= 3.0V
(3)
750
Input HIGH
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device.
2. Typical values are at V
CC
= 3.3V, +25C ambient.
3. Per driven input (control input only); A and B pins do not contribute to
I
CC
.
Switching Characteristics over 3.3V Operating Range
A
PI3C3244
Com.
Parameters Description
Conditions
(1)
Min.
Max. Units
t
PLH
Propagation Delay
(2,3)
C
L
= 50 pF,
0.25
t
PHL
Ax to Bx
R
L
= 500
t
PZH
Bus Enable Time
1.5
9.8
ns
t
PZL
BE to Ax or Bx
C
L
= 50 pF,
t
PHZ
Bus Disable Time
R
L
= 500
,
1.5
8.3
t
PLZ
BE to Ax or Bx
R = 500
Switching Characteristics over 2.5V Operating Range
Notes:
1. See test circuit and waveforms.
2. This parameter is guaranteed but not tested on Propagation Delays.
3. The bus switch contributes no propagational delay other than the RC delay of the ON resistance of the switch and the load
capacitance. The time constant for the switch alone is of the order of 0.25ns for 50pF load. Since this time constant is much smaller
than the rise/fall times of typical driving signals, it adds very little propagational delay to the system. Propagational delay of the
bus switch when used in a system is determined by the driving circuit on the driving side of the switch and its interaction with the
load on the driven side.
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PS8149B 12/10/99
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PI3C3244
2.5V/3.3V, High Bandwidth,
Hot Insertion, 8-Bit, 2-Port Bus Switch
Pericom Semiconductor Corporation
2380 Bering Drive San Jose, CA 95131 1-800-435-2336 Fax (408) 435-1100 http://www.pericom.com
4.0
2.0
0.0
0.0
1.0
2.0
3.0
4.0
5.0
V
OUT
, (V)
VIN, (V)
VCC =
3.3V
3.1V
2.9V
2.7V
2.5V
2.3V
3.6V
3.8V
3.4V
3.2V
3.0V
2.8V
Output Voltage vs. Input Voltage over Various Supply Voltages
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4
4
2
3
C
3
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T
-
0
2
C
5
8
+
o
t
C
0
4
Q
4
4
2
3
C
3
I
P
)
Q
(
P
O
S
Q
-
0
2
C
5
8
+
o
t
C
0
4
Ordering Information
Output Voltage vs. Input Voltage over Various Supply Voltages
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