|
ST Microelectronics |
M54HC157/158
M74HC157/158
HC157 QUAD 2 CHANNEL MULTIPLEXER
HC158 QUAD 2 CHANNEL MULTIPLEXER (INV.)
. HIGH SPEED
tPD = 10 ns (TYP.) AT VCC = 5 V
. LOW POWER DISSIPATION
ICC = 4 µA (MAX.) AT TA = 25 °C
. HIGH NOISE IMMUNITY
VNIH = VNIL = 28 % VCC (MIN.)
. OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
. SYMMETRICAL OUTPUT IMPEDANCE
IOH = IOL = 4 mA (MIN.)
. BALANCED PROPAGATION DELAYS
tPLH = tPHL
. WIDE OPERATING VOLTAGE RANGE
VCC (OPR) = 2 V TO 6 V
. PIN AND FUNCTION COMPATIBLE
WITH 54/74LS157/158
B1R
(Plastic Package)
F1R
(Ceramic Package)
M 1R
(Micro Package)
C1R
(Chip Carrier)
ORDER CODES :
M54HCXXXF1R M74HCXXXM1R
M74HCXXXB1R M74HCXXXC1R
PIN CONNECTIONS (top view)
HC157
DESCRIPTION
The M54/74HC157 and the M54/74HC158 are high
speed CMOS QUAD 2-CHANNEL MULTI-
PLEXER’s fabricated with silicon gate C2MOS tech-
nology. They achieve the high speed operation
similar to equivalent LSTTL while maintaining the
CMOS low power dissipation.
These devices consist of four 2-input digital multi-
plexers with common select and strobe inputs. The
HC158 is an inverting multiplexer while the HC157
is a non-inverting multiplexer. When the STROBE
input is held High, selection of data is inhibited and
all the outputs become Low in the M74HC157 and
High in the M74HC158. The SELECT decoding
determines whether the A or B inputs get routed to
their corresponding Y outputs. All inputs are
equipped with protection circuits against static dis-
charge and transient excess voltage.
February 1993
HC158
NC =
No Internal
Connection
1/11
M54/M74HC157 M54/M74HC158
CHIP CARRIER
HC157
HC158
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION (for HC157)
PIN No
1
2, 5, 11, 14
3, 6, 10, 13
4, 7, 9, 12
15
8
16
SYMBOL
SELECT
1A to 4A
1B to 4B
1Y to 4Y
STROBE
GND
VCC
NAME AND FUNCTION
Common Data Select
Input
Data Inputs From
Source A
Data Inputs From
Source B
Multiplexer Output
Strobe Input
Ground (0V)
Positive Supply Voltage
PIN DESCRIPTION (for HC158)
PIN No
1
2, 5, 11, 14
3, 6, 10, 13
4, 7, 9, 12
15
8
16
SYMBOL
SELECT
1A to 4A
1B to 4B
1Y to 4Y
STROBE
GND
VCC
NAME AND FUNCTION
Common Data Select
Input
Data Inputs From
Source A
Data Inputs From
Source B
Multiplexer Output
Strobe Input
Ground (0V)
Positive Supply Voltage
2/11
|