®
74VHCT157A
QUAD 2 CHANNEL MULTIPLEXER
PRELIMINARY DATA
s
s
s
s
s
s
s
s
s
s
HIGH SPEED: t
PD
= 6.2 ns (TYP.) at V
CC
= 5V
LOW POWER DISSIPATION:
I
CC
= 4
µA
(MAX.) at T
A
= 25
o
C
COMPATIBLE WITH TTL OUTPUTS:
V
IH
= 2V (MIN), V
IL
= 0.8V (MAX)
POWER DOWN PROTECTION ON INPUTS &
OUTPUTS
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 8 mA (MIN)
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 4.5V to 5.5V
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 157
IMPROVED LATCH-UP IMMUNITY
LOW NOISE: V
OLP
= 0.8V (Max.)
SOP
PACKAGE
SOP
TSSOP
T UBE
74VHCT157AM
TSSOP
T& R
74VHCT157AMTR
74VHCT157ATTR
ORDER CODES
DESCRIPTION
The 74VHCT157A is an high-speed CMOS
QUAD 2-CHANNEL MULTIPLEXER fabricated
with sub-micron silicon gate and double-layer
metal wiring C
2
MOS technology.
It consists of four 2-input digital multiplexers with
common select and strobe inputs. It is a
non-inverting multiplexer. When the STROBE
input is held high, selection of data is inhibited
and all the outputs become low. The SELECT
decoding determines whether the A or B inputs
get routed to their corresponding Y outputs.
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.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
March 2000
1/9
74VHCT157A
ABSOLUTE MAXIMUM RATINGS
Symbol
V
CC
V
I
V
O
V
O
I
IK
I
OK
I
O
I
CC
orI
GND
T
stg
T
L
Supply Voltage
DC Input Voltage
DC Output Voltage (see note 1)
DC Output Voltage (see note 2)
DC Input Diode Current
DC Output Diode Current
DC Output Current
DC V
CC
or Ground Current
Storage Temperature
Lead Temperature (10 sec)
Parameter
Value
-0.5 to +7.0
-0.5 to +7.0
-0.5 to +7.0
-0.5 to V
CC
+ 0.5
- 20
±
20
±
25
±
50
-65 to +150
300
Unit
V
V
V
V
mA
mA
mA
mA
o
o
C
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
1) V
CC
=0
2) High or Low State
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
I
V
O
V
O
T
op
dt/dv
Supply Voltage
Input Voltage
Output Voltage (see note 1)
Output Voltage (see note 2)
Operating Temperature
Input Rise and Fall Time (see note 3) (V
CC
= 5.0
±
0.5V)
Parameter
Valu e
4.5 to 5.5
0 to 5.5
0 to 5.5
0 to V
CC
-40 to +85
0 to 20
Unit
V
V
V
V
o
C
ns/V
1) V
CC
=0
2) High or Low State
3)V
IN
from0.8V to 2 V
DC SPECIFICATIONS
Symb ol
Parameter
T est Cond ition s
V
CC
(V)
V
IH
V
IL
V
OH
V
OL
I
I
I
CC
∆I
CC
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
Low Level Output
Voltage
Input Leakage Current
Quiescent Supply
Current
Additional Worst Case
Supply Current
Output Leakage
Current
4.5 to 5.5
4.5 to 5.5
4.5
4.5
4.5
4.5
0 to 5.5
5.5
5.5
I
O
=-50
µA
I
O
=-8 mA
I
O
=50
µA
I
O
=8 mA
V
I
= 5.5V or GND
V
I
= V
CC
orGND
One Input at 3.4V,
other input at V
CC
or
GND
V
OUT
= 5.5V
4.4
3.94
0.0
0.1
0.36
±0.1
4
1.35
4.5
o
Value
T
A
= 25 C
Min.
2
0.8
4.4
3.8
0.1
0.44
±1.0
40
1.5
Typ .
Max.
-40 to 85 C
Min .
2
0.8
Max.
o
Un it
V
V
V
V
µA
µ
A
mA
I
OPD
0
0.5
5.0
µA
3/9
74VHCT157A
AC ELECTRICAL CHARACTERISTICS
(Input t
r
= t
f
=3 ns)
Symb ol
Parameter
Test Co ndition
V
CC
C
L
(V)
(pF )
5.0
(*)
5.0
(*)
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay
Time
A, B to Y
Propagation Delay
Time
SELECT to Y
Propagation Delay
Time
STROBE to Y
15
50
15
50
15
50
Value
T
A
= 25 C
Min. Typ . Max.
6.2
9.7
o
Un it
-40 to 85 C
Min . Max.
1.0
11.5
1.0
1.0
1.0
1.0
1.0
15.0
15.5
19.0
16.0
19.5
ns
ns
o
8.7
8.4
10.9
8.7
11.2
13.2
13.2
16.7
13.6
17.1
5.0
(*)
5.0
(*)
5.0
(*)
5.0
(*)
ns
(*) Voltage range is 5V
±
0.5V
CAPACITIVE CHARACTERISTICS
Symb ol
Parameter
T est Cond ition s
o
Value
T
A
= 25 C
Min.
Typ .
4
20
Max.
10
-40 to 85 C
Min .
Max.
10
o
Un it
C
IN
C
PD
Input Capacitance
Power Dissipation
Capacitance (note 1)
pF
pF
1) C
PD
isdefined as the value of the IC’sinternal equivalent capacitance which is calculated fromthe operating current consumption without load. (Referto
Test Circuit).Average operating current can be obtained by the following equation. I
CC
(opr) = C
PD
•
V
CC
•
f
IN
+ I
CC
/4 (per Channel)
4/9
74VHCT157A
DYNAMIC SWITCHING CHARACTERISTICS
Symb ol
Parameter
T est Cond ition s
V
CC
(V)
V
OLP
V
OLV
V
IHD
V
ILD
Dynamic Low Voltage
Quiet Output (note 1, 2)
Dynamic High Voltage
Input (note 1, 3)
Dynamic Low Voltage
Input (note 1, 3)
5.0
-0.8
5.0
5.0
C
L
= 50 pF
2.0
0.8
o
Value
T
A
= 25 C
Min.
Typ .
0.3
-0.3
Max.
0.8
-40 to 85 C
Min .
Max.
o
Un it
V
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 5.0V, (n -1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to5.0V. Inputs under test switching: 5.0V to threshold (V
ILD
), 0V to threshold (V
IHD
), f=1MHz.
TEST CIRCUIT
C
L
= 15/50 pF or equivalent (includes jig and probe capacitance)
R
T
= Z
OUT
of pulse generator (typically 50Ω)
5/9
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