74VHCT257A_04 [STMICROELECTRONICS]
QUAD 2 CHANNEL MULTIPLEXER (3-STATE); QUAD 2通道多路复用器（ 3 -STATE ）
| 型号： | 74VHCT257A_04 |
| 厂家： | 
ST |
| 描述： | QUAD 2 CHANNEL MULTIPLEXER (3-STATE) |
| 文件： | 总13页 (文件大小：314K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
74VHCT257A
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)
■
■
HIGH SPEED: t = 4.8 ns (TYP.) at V = 5V
PD CC
LOW POWER DISSIPATION:
I
= 4 µA (MAX.) at T =25°C
CC
A
■
■
■
■
■
■
COMPATIBLE WITH TTL OUTPUTS:
= 2V (MIN.), V = 0.8V (MAX)
POWER DOWN PROTECTION ON INPUTS
& OUTPUTS
V
IH
IL
SOP
TSSOP
T & R
SYMMETRICAL OUTPUT IMPEDANCE:
|I | = I = 8 mA (MIN)
OH
OL
Table 1: Order Codes
PACKAGE
BALANCED PROPAGATION DELAYS:
t
t
PLH
PHL
OPERATING VOLTAGE RANGE:
(OPR) = 4.5V to 5.5V
SOP
74VHCT257AMTR
74VHCT257ATTR
V
CC
TSSOP
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
■
■
IMPROVED LATCH-UP IMMUNITY
If SELECT INPUT is held "Low", "A" data is
selected, when SELECT INPUT is "High", "B" data
is chosen.
LOW NOISE: V
= 0.8V (MAX.)
OLP
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
device can be used to interface 5V to 3V since all
inputs are equipped with TTL threshold.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
DESCRIPTION
The 74VHCT257A is an advanced high-speed
CMOS QUAD 2-CHANNEL MULTIPLEXER
(3-STATE) fabricated with sub-micron silicon gate
2
and double-layer metal wiring C MOS technology.
It is composed of four independent 2-channel
multiplexers with common SELECT and ENABLE
INPUT(OE). The VHCT257A is a non-inverting
multiplexer. When the ENABLE INPUT is held
"High", all outputs become high impedance state.
Figure 1: Pin Connection And IEC Logic Symbols
Rev. 3
1/13
December 2004
74VHCT257A
Figure 2: Input Equivalent Circuit
Table 2: Pin Description
PIN N°
SYMBOL
NAME AND FUNCTION
1
SELECT
Common Data Select
Inputs
2, 5, 11, 14
3, 6, 10, 13
4, 7, 9, 12
15
1A to 4A
1B to 4B
1Y to 4Y
OE
Data Inputs From Source
A
Data Inputs From Source
B
3 State Multiplexer
Outputs
3 State Output Enable
Inputs (Active LOW)
8
GND
Ground (0V)
16
V
Positive Supply Voltage
CC
Table 3: Truth Table
INPUTS
OUTPUT
Y
OE
SELECT
A
B
H
L
L
L
L
X
L
X
L
X
X
X
L
Z
L
L
H
X
X
H
L
H
H
H
H
X: Don’t Care
Z: High Impedance
Figure 3: Logic Diagram
This logic diagram has not be used to estimate propagation delays
2/13
74VHCT257A
Table 4: Absolute Maximum Ratings
Symbol
Parameter
Value
Unit
V
Supply Voltage
-0.5 to +7.0
-0.5 to +7.0
-0.5 to +7.0
V
V
V
CC
V
DC Input Voltage
I
V
DC Output Voltage (see note 1)
DC Output Voltage (see note 2)
DC Input Diode Current
DC Output Diode Current
DC Output Current
O
V
-0.5 to V + 0.5
V
O
CC
I
- 20
± 20
mA
mA
mA
mA
°C
IK
I
OK
I
± 25
O
I
or I
DC V or Ground Current
± 50
CC
GND
CC
T
Storage Temperature
-65 to +150
300
stg
T
Lead Temperature (10 sec)
°C
L
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) Output in OFF State
2) High or Low State
Table 5: Recommended Operating Conditions
Symbol
Parameter
Value
Unit
V
Supply Voltage
4.5 to 5.5
0 to 5.5
0 to 5.5
V
V
CC
V
Input Voltage
I
V
Output Voltage (see note 1)
Output Voltage (see note 2)
Operating Temperature
V
O
V
0 to V
V
O
CC
T
-55 to 125
0 to 20
°C
ns/V
op
Input Rise and Fall Time (see note 3) (V = 5.0 ± 0.5V)
dt/dv
CC
1) Output in OFF State
2) High or Low State
3) V from 0.8V to 2V
IN
3/13
74VHCT257A
Table 6: DC Specifications
Test Condition
Value
T = 25°C
Symbol
Parameter
-40 to 85°C -55 to 125°C Unit
A
V
CC
(V)
Min. Typ. Max. Min. Max. Min. Max.
V
High Level Input
Voltage
4.5 to
5.5
IH
2
2
2
V
V
V
Low Level Input
Voltage
4.5 to
5.5
IL
0.8
0.8
0.8
V
High Level Output
Voltage
I =-50 µA
4.5
4.5
4.5
4.5
4.4
4.5
0.0
4.4
3.8
4.4
3.7
OH
O
V
V
I =-8 mA
3.94
O
V
Low Level Output
Voltage
I =50 µA
0.1
0.1
0.1
OL
OZ
O
I =8 mA
0.36
0.44
0.55
O
I
High Impedance
Output Leakage
Current
V = V or V
I
IH
IL
5.5
±0.25
± 2.5
± 2.5
µA
V
= 0V to 5.5V
O
I
Input Leakage
Current
0 to
5.5
I
V = 5.5V or GND
± 0.1
± 1.0
± 1.0
µA
µA
I
I
Quiescent Supply
Current
CC
V = V or GND
5.5
5.5
0
4
40
40
I
CC
+I
Additional Worst
Case Supply
Current
One Input at 3.4V,
CC
other input at V
1.35
0.5
1.5
5.0
1.5
5.0
mA
CC
or GND
I
Output Leakage
Current
OPD
V
= 5.5V
µA
OUT
Table 7: AC Electrical Characteristics (Input t = t = 3ns)
r
f
Test Condition
(*)
Value
T = 25°C
Symbol
Parameter
-40 to 85°C -55 to 125°C Unit
Min. Typ. Max. Min. Max. Min. Max.
A
V
C
L
CC
(V)
(pF)
t
t
Propagation Delay
Time A, B, to Y
5.0
5.0
5.0
5.0
5.0
5.0
15
50
15
50
15
50
4.8
5.5
6.0
7.0
5.8
6.5
7.0
8.0
6.8
8.8
6.8
8.8
1.0
1.0
1.0
1.0
1.0
1.0
8.0
9.0
1.0
1.0
1.0
1.0
1.0
1.0
8.0
9.0
PLH
PHL
ns
ns
ns
ns
t
t
Propagation Delay
Time SELECT to Y
8.0
8.0
PLH
10.0
8.0
10.0
8.0
PHL
t
t
Output Enable
Time
PZL
10.0
10.0
PZH
t
Output Disable
Time
PLZ
5.0
50
5.7
7.9
1.0
9.0
1.0
9.0
t
PHZ
(*) Voltage range is 5.0V ± 0.5V
4/13
74VHCT257A
Table 8: Capacitive Characteristics
Test Condition
Value
-40 to 85°C -55 to 125°C Unit
Min. Typ. Max. Min. Max. Min. Max.
T = 25°C
Symbol
Parameter
A
C
Input Capacitance
4
6
10
10
10
pF
pF
IN
Output
Capacitance
C
OUT
C
Power Dissipation
Capacitance
(note 1)
PD
23
pF
1) C is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without
PD
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I
Channel)
= C x V x f + I /4 (per
CC(opr)
PD CC IN CC
Table 9: Dynamic Switching Characteristics
Test Condition
Value
-40 to 85°C -55 to 125°C Unit
Min. Typ. Max. Min. Max. Min. Max.
T = 25°C
Symbol
Parameter
A
V
CC
(V)
V
Dynamic Low
Voltage Quiet
Output (note 1, 2)
0.3
0.8
OLP
5.0
V
-0.8
2.0
-0.3
OLV
Dynamic High
Voltage Input
(note 1, 3)
V
C = 50 pF
5.0
5.0
V
IHD
L
Dynamic Low
Voltage Input
(note 1, 3)
V
0.8
ILD
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n-1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.0V. Inputs under test switching: 3.0V to threshold (V ), 0V to threshold
ILD
(V ), f=1MHz.
IHD
5/13
74VHCT257A
Figure 4: Test Circuit
TEST
SWITCH
t
t
t
, t
Open
PLH PHL
, t
V
CC
PZL PLZ
, t
GND
PZH PHZ
C
R
R
=15/ 50pF or equivalent (includes jig and probe capacitance)
L
L
T
= R = 1KΩ or equivalent
1
= Z
of pulse generator (typically 50Ω)
OUT
Figure 5: Waveform - Propagation Delays For Inverting Conditions (f=1MHz; 50% duty cycle)
6/13
74VHCT257A
Figure 6: Waveform - Propagation Delays For Non-inverting Conditions (f=1MHz; 50% duty cycle)
Figure 7: Waveform - Output Enable And Disable Time (f=1MHz; 50% duty cycle)
7/13
74VHCT257A
SO-16 MECHANICAL DATA
mm.
inch
TYP.
DIM.
MIN.
TYP
MAX.
1.75
0.25
1.64
0.46
0.25
MIN.
MAX.
0.068
0.010
0.063
0.018
0.010
A
a1
a2
b
0.1
0.004
0.35
0.19
0.013
0.007
b1
C
0.5
0.019
c1
D
45° (typ.)
9.8
5.8
10
0.385
0.228
0.393
0.244
E
6.2
e
1.27
8.89
0.050
0.350
e3
F
3.8
4.6
0.5
4.0
5.3
0.149
0.181
0.019
0.157
0.208
0.050
0.024
G
L
1.27
0.62
M
S
8° (max.)
0016020D
8/13
74VHCT257A
TSSOP16 MECHANICAL DATA
mm.
inch
TYP.
DIM.
MIN.
TYP
MAX.
1.2
MIN.
MAX.
0.047
0.006
0.041
0.012
0.0079
0.201
0.260
0.176
A
A1
A2
b
0.05
0.8
0.15
1.05
0.30
0.20
5.1
0.002
0.031
0.007
0.004
0.193
0.244
0.169
0.004
0.039
1
0.19
0.09
4.9
c
D
5
6.4
0.197
0.252
E
6.2
6.6
E1
e
4.3
4.4
4.48
0.173
0.65 BSC
0.0256 BSC
K
0˚
8˚
0˚
8˚
L
0.45
0.60
0.75
0.018
0.024
0.030
A2
A
K
L
b
e
A1
c
E
D
E1
PIN 1 IDENTIFICATION
1
0080338D
9/13
74VHCT257A
Tape & Reel SO-16 MECHANICAL DATA
mm.
TYP
inch
TYP.
DIM.
MIN.
MAX.
330
MIN.
MAX.
12.992
0.519
A
C
12.8
20.2
60
13.2
0.504
0.795
2.362
D
N
T
22.4
6.65
10.5
2.3
0.882
0.262
0.414
0.090
0.161
0.319
Ao
Bo
Ko
Po
P
6.45
10.3
2.1
0.254
0.406
0.082
0.153
0.311
3.9
4.1
7.9
8.1
10/13
74VHCT257A
Tape & Reel TSSOP16 MECHANICAL DATA
mm.
TYP
inch
TYP.
DIM.
MIN.
MAX.
330
MIN.
MAX.
12.992
0.519
A
C
12.8
20.2
60
13.2
0.504
0.795
2.362
D
N
T
22.4
6.9
5.5
1.8
4.1
8.1
0.882
0.272
0.217
0.071
0.161
0.319
Ao
Bo
Ko
Po
P
6.7
5.3
1.6
3.9
7.9
0.264
0.209
0.063
0.153
0.311
11/13
74VHCT257A
Table 10: Revision History
Date
Revision
Description of Changes
Order Codes Revision - pag. 1.
16-Dec-2004
3
12/13
74VHCT257A
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of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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13/13
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