1
PS8334A 09/28/99
Product Description
Pericom Semiconductors PI3B series of logic circuits are produced
using the Companys advanced sub micron CMOS technology,
achieving industry leading performance.
The PI3B33X257 is a 3.3V, 24:12 multiplexer/demultiplexer with
three-state outputs. Inputs can be connected to outputs with low
on resistance (5 Ohm) with no additional ground bounce noise or
propagation delay.
Logic Block Diagram
En
Sn
YA
(2)
YB
(2)
YC
(2)
YD
(2)
Function
H
X
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Disable
L
L
IA0
IB0
IC0
ID0
S = 0
L
H
IA1
IB1
IC1
ID1
S = 1
Truth Table
(1)
Notes: 1. H = High Voltage Level
L = Low Voltage Level
2. n = 0 YA, YB, YC, YD
n = 1 YE, YF, YG, YH
n = 2 YI, YJ, YK, YL
E
0
IA
0
IA
1
IB
0
IB
1
IC
0
IC
1
ID
0
ID
1
S
0
YA
YB
YC
YD
E
1
IE
0
IE
1
IF
0
IF
1
IG
0
IG
1
IH
0
IH
1
S
1
YE
YF
YG
YH
E
2
II
0
II
1
IJ
0
IJ
1
IK
0
IK
1
IL
0
IL
1
S
2
YI
YJ
YK
YL
1
2
3
4
5
6
7
8
9
48
10
47
11
46
12
45
13
44
14
43
15
42
16
41
17
40
18
39
19
38
20
37
21
36
22
35
23
34
24
33
32
31
30
29
28
27
26
25
IA
0
IA1
IB
0
IB1
YA
YB
GND
S
0
S
1
IE
0
IE1
IF
0
IF1
YE
YF
GND
S
2
II
0
II1
IJ
0
IJ
1
YI
YJ
GND
YK
IK1
IK
0
YL
IL
1
IL
0
E
2
V
CC
YG
IG
1
IG
0
YH
IH
1
IH
0
V
CC
YC
IC
1
IC
0
YD
ID
1
ID
0
V
CC
E
1
E
0
48-Pin Product Configuration
48-Pin
B
Product Features
Permits Hot Insertion
Near zero propagation delay
5 Ohm switches connect inputs to outputs
Direct bus connection when switches are ON
Ultra Low Quiescent Power (0.2A Typical)
Ideally suited for notebook applications
TTL - compatible control of input levels
Fast switching speed - 4.5ns max.
Packages available:
48-pin 150 mil wide plastic BQSOP (B)
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PI3B33X257
3.3V, 24:12 Mux/Demux BusSwitch
2
PS8334A 09/28/99
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PI3B33X257
3.3V, 24:12 Mux/Demux BusSwitch
DC Electrical Characteristics
(Over the Operating Range, T
A
= 40C to +85C, V
CC
= 3.3V 5%)
Parameters Description
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Units
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH Level
2.0
V
V
IL
Input LOW Voltage
Guaranteed Logic LOW Level
0.5
0.8
V
I
IH
Input HIGH Current
V
CC
= Max., V
IN
= V
CC
50
A
I
IL
Input LOW Current
V
CC
= Max., V
IN
= GND
1
A
I
OZH
High Impedance Output Current 0
I, Y
V
CC
50
A
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18mA
1.2
V
R
ON
Switch On Resistance
(3)
V
CC
= Min., V
IN
= 0.0V, I
ON
= 48mA or 64mA
5
7
V
CC
= Min., V
IN
= 2.4V, I
ON
= 15mA
10
15
Storage Temperature ............................................................. 65C to +150C
Ambient Temperature with Power Applied ............................. 40C to +85C
Supply Voltage to Ground Potential (Inputs & V
CC
Only) ...... 0.5V to +7.0V
Supply Voltage to Ground Potential (Outputs & D/O Only) .... 0.5V to +7.0V
DC Input Voltage ..................................................................... 0.5V to +7.0V
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.
Capacitance
(T
A
= 25C, f = 1 MHz)
Parameters
(4)
Description
Test Conditions
Typ.
Max.
Units
C
IN
Input Capacitance
V
IN
= 0V
3.0
pF
C
OFF
In/Yn Capacitance, Switch Off
V
IN
= 0V
17.0
pF
C
ON
In/Yn Capacitance, Switch On
V
IN
= 0V
25.0
pF
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. Measured by the voltage drop between I and Y pin at indicated current through the switch. ON resistance is determined by the
lower of the voltages on the two (I,Y) pins.
4. This parameter is determined by device characterization but is not production tested.
Product Pin Description
Pin Name
Description
IAn-ILn
Data Inputs
S
Select Inputs
En
Enable
YA-YL
Data Outputs
GND
Ground
V
CC
Power
NC
No Connect
Maximum Ratings
(Above which the useful life may be impaired. For user guidelines, not tested.)
3
PS8334A 09/28/99
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PI3B33X257
3.3V, 24:12 Mux/Demux BusSwitch
PI3B33X257
Com.
Parameters Description
Conditions
(1)
Min.
Max.
Units
t
IY
Propagation Delay
(2,3)
C
L
= 50pF
0.25
In to Yn
R
L
= 500
t
SY
Bus Select Time
1
4.5
ns
Sn to Yn
t
PZH
Bus Disable Time
1
4.5
t
PZL
E to Yn
t
PHZ
Bus Disable Time
1
4.8
t
PLZ
E to Yn
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
0.1
3.0
A
Supply Current
I
CC
Supply Current per
V
CC
= Max.
V
IN
= 3.0V
(3)
750
A
Input @ TTL 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 TTL driven input (V
IN
= 3.4V, control inputs only); I and Y pins do not contribute to I
CC
.
Switching Characteristics over 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 deter-
mined by the driving circuit on the driving side of the switch and its interaction with
the load on the driven side.
Pericom Semiconductor Corporation
2380 Bering Drive San Jose, CA 95131 1-800-435-2336 Fax (408) 435-1100 http://www.pericom.com
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Ordering Information
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