M54HCT157/158
M74HCT157/158
April 1993
HCT158 QUAD 2 CHANNEL MULTIPLEXER (INV.)
HCT157 QUAD 2 CHANNEL MULTIPLEXER
B1R
(Plastic Package)
ORDER CODES :
M54HCTXXXF1R M74HCTXXXM1R
M74HCTXXXB1R M74HCTXXXC1R
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS (top view)
NC =
No Internal
Connection
HCT158
HCT157
DESCRIPTION
.HIGH SPEED
tPD = 21 ns (TYP.) AT VCC =5V
.LOW POWER DISSIPATION
I
CC
=4 µA (MAX.) AT T
A
=25 °C
.COMPATIBLE WITH TTL OUTPUTS
VIH = 2V (MIN.) VIL = 0.8V (MAX)
.OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.SYMMETRICAL OUTPUT IMPEDANCE
IOH =IOL = 4 mA (MIN.)
.BALANCED PROPAGATION DELAYS
t
PLH
=t
PHL
.PIN AND FUNCTION COMPATIBLE
WITH 54/74LS157/158
The M54/74HCT157 and the M54/74HCT158 are
high speed CMOS QUAD 2-CHANNEL MULTI-
PLEXERs fabricated with silicon gate C
2
MOS 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
HCT158 is an inverting multiplexer while the
HCT157 is a non-inverting multiplexer. When the
STROBE input is held High, selection of data is in-
hibited and all the outputs become Low in the
M74HCT157 and High in the M74HCT158. The SE-
LECT decoding determines whether the A or B in-
puts get routed to their corresponding Y outputs. All
inputs are equipped with protection circuits against
static discharge and transient excess voltage.
M54/74HCT devices are designed to directly inter-
face HSC
2
MOS systems with TTL and NMOS com-
ponents. They are also plug in replacements for
LSTTL devices giving a reduction of power con-
sumption.
1/11