STMICROELECTRONICS 74ACT257M

74ACT257
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)
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HIGH SPEED: tPD =5 ns (TYP.) at VCC = 5V
LOW POWER DISSIPATION:
ICC = 8 µA (MAX.) at TA = 25 oC
COMPATIBLE WITH TTL OUTPUTS
VIH = 2V (MIN), VIL = 0.8V (MAX)
50Ω TRANSMISSION LINE DRIVING
CAPABILITY
SYMMETRICAL OUTPUT IMPEDANCE:
|IOH| = IOL = 24 mA (MIN)
BALANCED PROPAGATION DELAYS:
tPLH ≅ tPHL
OPERATING VOLTAGE RANGE:
VCC (OPR) = 4.5V to 5.5V
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
IMPROVED LATCH-UP IMMUNITY
DESCRIPTION
The ACT257 is an advanced high-speed CMOS
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C2MOS technology.
It is ideal for low power applications mantaining
high speed operation similar to equivalent Bipolar
Schottky TTL.
These IC’s are composed of an independent 2
channel multiplexer with common SELECT and
B
M
(Plastic Package)
(Micro Package)
ORDER CODES :
74ACT257B
74ACT257M
ENABLE INPUT.
The AC257 is a non inverting multiplexer.
When the ENABLE INPUT is held ”High” outputs
of both IC’s become high impedance state. If
SELECT INPUT is held ”Low”, ”A” data is
selected, when SELECT INPUT is ”High”, ”B”
data is closen.
The device is designed to interface directly High
Speed CMOS systems with TTL, NMOS and
CMOS output voltage levels.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
April 1997
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74ACT257
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
PIN No
SYMBOL
NAME AND F UNCTIO N
1
SELECT
Common Data Select Input
2, 5, 14, 11
1A to 4A
Data Input From Source A
3, 6, 13, 10
1B to 4B
Data Inputs from Source B
4, 7, 12, 9
1Y to 4Y
15
OE
8
GND
Ground (0V)
16
VCC
Positive Supply Voltage
3 State Multiplexer Outputs
3 State Output Enable
Inputs (Active LOW)
TRUTH TABLE
INPUT S
OE
SELECT
A
B
Y
H
X
X
X
Z
L
L
L
X
L
L
L
H
X
H
L
H
X
L
L
L
H
X
H
H
X = DON’T CARE Z = HIGH IMPEDANCE
LOGIC DIAGRAMS
This logic diagram has not be used to estimate propagation delays
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OUT PUT S
74ACT257
ABSOLUTE MAXIMUM RATINGS
Symbol
VCC
Parameter
Supply Voltage
Value
Unit
-0.5 to +7
V
VI
DC Input Voltage
-0.5 to VCC + 0.5
V
VO
DC Output Voltage
-0.5 to VCC + 0.5
V
IIK
DC Input Diode Current
± 20
mA
IOK
DC Output Diode Current
± 20
mA
IO
DC Output Current
± 50
mA
± 200
mA
ICC or IGND DC VCC or Ground Current
Tstg
Storage Temperature
TL
Lead Temperature (10 sec)
-65 to +150
o
C
300
o
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
RECOMMENDED OPERATING CONDITIONS
Symbol
Valu e
Unit
Supply Voltage
4.5 to 5.5
V
VI
Input Voltage
0 to VCC
V
VO
Output Voltage
0 to VCC
VCC
Top
dt/dv
Parameter
Operating Temperature:
Input Rise and Fall Time VCC = 4.5 to 5.5V (note 1)
-40 to +85
8
V
o
C
ns/V
1) VIN from 0.8 V to 2.0 V
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74ACT257
DC SPECIFICATIONS
Symbol
Parameter
Test Con dition s
VIH
High Level Input Voltage
4.5
5.5
VIL
Low Level Input Voltage
4.5
5.5
VOH
High Level Output
Voltage
4.5
5.5
Low Level Output
Voltage
VO = 0.1 V or
VCC - 0.1 V
Min.
Typ.
2.0
1.5
2.0
2.0
1.5
2.0
VO = 0.1 V or
VCC - 0.1 V
(*)
VI =
V IH or
V IL
Unit
-40 to 85 o C
Max.
Min .
Max.
V
1.5
0.8
0.8
1.5
0.8
0.8
IO=-50 µA
4.4
4.49
4.4
IO=-50 µA
5.4
5.49
5.4
V
V
IO=-24 mA
3.86
5.5
IO=-24 mA
4.86
4.5
IO=50 µA
0.001
0.1
0.1
IO=50 mA
0.001
0.1
0.1
IO=24 mA
0.36
0.44
IO=24 mA
0.36
0.44
±0.1
±1
µA
±0.5
±5
µA
1.5
mA
80
µA
4.5
VOL
Value
T A = 25 oC
V CC
(V)
5.5
4.5
5.5
V I (*) =
V IH or
V IL
3.76
4.76
V
Input Leakage Current
5.5
VI = VCC or GND
IOZ
3 State Output Leakage
Current
5.5
VI = VIH or VIL
VO = VCC or GND
ICCT
Max ICC /Input
5.5
VI = VCC -2.1 V
ICC
Quiescent Supply
Current
5.5
VI = VCC or GND
IOLD
Dynamic Output Current
(note 1, 2)
5.5
VOLD = 1.65 V max
75
mA
VOHD = 3.85 V min
-75
mA
II
IOHD
1) Maximum test duration 2ms, one output loaded at time
2) Incident wave switching is guaranteed on transmission lines with impedances as low as 50 Ω.
(*) All outputs loaded.
4/10
0.6
8
74ACT257
AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, RL = 500 Ω, Input tr = t f =3 ns)
Symbol
Parameter
T est Cond ition
V CC
(V)
Value
T A = 25 oC
-40 to 85 o C
Min. Typ. Max. Min . Max.
Unit
(*)
5.0
7.0
8.0
ns
5.0
(*)
6.0
9.0
10.0
ns
Output Enable Time
5.0(*)
5.0
8.0
9.0
ns
Output Disable Time
5.0
(*)
6.0
9.0
10.0
ns
tPLH
tPHL
Propagation Delay Time
A, B to Y
5.0
tPLH
tPHL
Propagation Delay Time
SEL to Y
tPZL
tPZH
tPLZ
tPHZ
(*) Voltage range is 5V ± 0.5V
CAPACITIVE CHARACTERISTICS
Symbol
Parameter
Test Con dition s
V CC
(V)
Value
T A = 25 oC
Min.
Typ.
Max.
Unit
-40 to 85 o C
Min .
Max.
CIN
Input Capacitance
5.0
4
pF
C OUT
Input Capacitance
5.0
8
pF
C PD
Power Dissipation
Capacitance (note 1)
5.0
31
pF
1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to
Test Circuit). Average operating current can be obtained by the following equation. ICC(opr) = CPD • VCC • fIN + ICC/n (per circuit)
TEST CIRCUIT
TEST
t PLH, tPHL
SWITCH
Open
t PZL, tPLZ
2VCC
t PZH, tPHZ
Open
CL = 50 pF or equivalent (includes jig and probe capacitance)
RL = R1 = 500Ω or equivalent
RT =ZOUT of pulse generator (typically 50Ω)
5/10
74ACT257
WAVEFORM 1: PROPAGATION DELAYS FOR INVERTING CONDITIONS (f=1MHz; 50% duty cycle)
WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING CONDITIONS (f=1MHz; 50% duty
cycle)
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74ACT257
WAVEFORM 3: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
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74ACT257
Plastic DIP16 (0.25) MECHANICAL DATA
mm
DIM.
MIN.
a1
0.51
B
0.77
TYP.
inch
MAX.
MIN.
TYP.
MAX.
0.020
1.65
0.030
0.065
b
0.5
0.020
b1
0.25
0.010
D
20
0.787
E
8.5
0.335
e
2.54
0.100
e3
17.78
0.700
F
7.1
0.280
I
5.1
0.201
L
Z
3.3
0.130
1.27
0.050
P001C
8/10
74ACT257
SO16 MECHANICAL DATA
mm
DIM.
MIN.
TYP.
A
a1
inch
MAX.
MIN.
TYP.
1.75
0.1
0.068
0.2
a2
MAX.
0.004
0.007
1.65
0.064
b
0.35
0.46
0.013
0.018
b1
0.19
0.25
0.007
0.010
C
0.5
0.019
c1
45 (typ.)
D
9.8
E
5.8
10
0.385
6.2
0.228
0.393
0.244
e
1.27
0.050
e3
8.89
0.350
F
3.8
4.0
0.149
0.157
G
4.6
5.3
0.181
0.208
L
0.5
1.27
0.019
0.050
M
S
0.62
0.024
8 (max.)
P013H
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74ACT257
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsability for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No
license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectonics.
 1997 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved
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