M54HCT138
M74HCT138
February 1993
3 TO 8 LINE DECODER (INVERTING)
B1R
(Plastic Package)
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS (top view)
NC =
No Internal
Connection
INPUT AND OUTPUT EQUIVALENT CIRCUIT
ORDER CODES :
M54HCT138F1R
M74HCT138M1R
M74HCT138B1R
M74HCT138C1R
DESCRIPTION
.
HIGH SPEED
t
PD
= 16 ns (TYP.) at V
CC
= 5 V
.
LOW POWER DISSIPATION
I
CC
= 4
A AT T
A
= 25
C
.
OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.
BALANCED PROPAGATION DELAYS
t
PLH
= t
PHL
.
SYMMETRICAL OUTPUT IMPEDANCE
|I
OH
| = I
OL
.
COMPATIBLE WITH TTL OUTPUTS
V
IH
= 2V (MIN.) V
IL
= 0.8V (MAX)
.
PIN AND FUNCTION COMPATIBLE
WITH 54/74LS138
The M54/74HC138 is a high speed CMOS 3 TO 8
LINE DECODER fabricated in silicon gate C
2
MOS
technology. It has the same high speed perform-
ance of LSTTL combined with true CMOS low power
consumption. If the device is enabled, 3 binary se-
lect inputs (A, B and C) determine which one of the
outputs will go low. If enable input G1 is held low or
either G2A or G2B is held high, the decoding func-
tion is inhibited and all the 8 outputs go high. Three
enable inputs are provided to ease cascade connec-
tion and application of address decoders for mem-
ory systems. All inputs are equipped with protection
circuits against static discharge and tran- sient ex-
cess voltage.This integrated circuit has input and
output characteristics that are fully compatible with
54/74 LSTTL logic families. M54/74HCT devices
are designed to directly interface HSC
2
MOS sys-
tems with TTL and NMOS components. They are
also plug in replacements for LSTTL devices giving
a reduction of power consumption.
1/10
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7
V
V
I
DC Input Voltage
-0.5 to V
CC
+ 0.5
V
V
O
DC Output Voltage
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
20
mA
I
OK
DC Output Diode Current
20
mA
I
O
DC Output Source Sink Current Per Output Pin
25
mA
I
CC
or I
GND
DC V
CC
or Ground Current
50
mA
P
D
Power Dissipation
500 (*)
mW
T
stg
Storage Temperature
-65 to +150
o
C
T
L
Lead Temperature (10 sec)
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.
(*) 500 mW:
65
o
C derate to 300 mW by 10mW/
o
C: 65
o
C to 85
o
C
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
4.5 to 5.5
V
V
I
Input Voltage
0 to V
CC
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature: M54HC Series
M74HC Series
-55 to +125
-40 to +85
o
C
o
C
t
r
, t
f
Input Rise and Fall Time (V
CC
= 4.5 to 5.5V)
0 to 500
ns
M54/M74HCT138
3/10
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input t
r
= t
f
= 6 ns)
Symbol
Parameter
Test Conditions
Value
Unit
V
CC
(V)
T
A
= 25
o
C
54HC and 74HC
-40 to 85
o
C
74HC
-55 to 125
o
C
54HC
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
t
TLH
t
THL
Output Transition
Time
4.5
8
15
19
22
ns
t
PLH
t
PHL
Propagation
Delay Time
(A, B, C - Y)
4.5
17
30
38
45
ns
t
PLH
t
PHL
Propagation
Delay Time
(G1 - Y)
4.5
16
30
38
45
ns
t
PLH
t
PHL
Propagation
Delay Time
(G2 - Y)
4.5
19
30
38
45
ns
C
IN
Input Capacitance
5
10
10
10
pF
C
PD
(*)
Power Dissipation
Capacitance
52
pF
(*) C
PD
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 operting current can be obtained by the following equation. I
CC
(opr) = C
PD
V
CC
f
IN
+ I
CC
TEST CIRCUIT I
CC
(Opr.)
SWITCHING CHARACTERISTICS TEST WAVEFORM
INPUT WAVEFORM IS THE SAME
AS THAT IN CASE OF SWITCHING
CHARACTERISTICS TEST.
M54/M74HCT138
5/10
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