M54HC238
M74HC238
October 1993
3 TO 8 LINE DECODER
B1R
(Plastic Package)
ORDER CODES :
M54HC238F1R
M74HC238M1R
M74HC238B1R
M74HC238C1R
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS (top view)
NC =
No Internal
Connection
DESCRIPTION
.
HIGH SPEED
t
PD
= 14 ns (TYP.) AT V
CC
= 5 V
.
LOW POWER DISSIPATION
I
CC
= 4
A (MAX.) AT T
A
= 25
C
.
HIGH NOISE IMMUNITY
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
.
OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.
SYMMETRICAL OUTPUT IMPEDANCE
|I
OH
| = I
OL
= 4 mA (MIN.)
.
BALANCED PROPAGATION DELAYS
t
PLH
= t
PHL
.
WIDE OPERATING VOLTAGE RANGE
V
CC
(OPR) = 2 V TO 6 V
.
PIN AND FUNCTION COMPATIBLE
WITH 54/74LS238
The M54/74HC238 is a high speed CMOS 3 to 8 line
decoder fabricated in silicon gate C
2
MOS technology.
It has the same high speed performance of LSTTL
combined with true CMOS low power consumption. If
the device is enabled, 3 binary select inputs (A, B and
C) determine which one of outputs will go high. Enable
input G1 is held "Low" or either G2A or G2B is held
"High" decoding function is inhibited and all the 8 out-
puts go low. Three enable inputs are provided to ease
cascade connection and application of this address
decoder in memory systems.
All inputs are equipped with protection circuits against
static discharge and transient excess voltage.
1/10
TRUTH TABLE
INPUTS
OUTPUS
SELECTED
OUTPUT
ENABLE
SELECT
G2B
G2A
G1
C
B
A
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
X
X
L
X
X
X
L
L
L
L
L
L
L
L
NONE
X
H
X
X
X
X
L
L
L
L
L
L
L
L
NONE
H
X
X
X
X
X
L
L
L
L
L
L
L
L
NONE
L
L
H
L
L
L
H
L
L
L
L
L
L
L
Y0
L
L
H
L
L
H
L
H
L
L
L
L
L
L
Y1
L
L
H
L
H
L
L
L
H
L
L
L
L
L
Y2
L
L
H
L
H
H
L
L
L
H
L
L
L
L
Y3
L
L
H
H
L
L
L
L
L
L
H
L
L
L
Y4
L
L
H
H
L
H
L
L
L
L
L
H
L
L
Y5
L
L
H
H
H
L
L
L
L
L
L
L
H
L
Y6
L
L
H
H
H
H
L
L
L
L
L
L
L
H
Y7
X: Don't Care
PIN DESCRIPTION
PIN No
SYMBOL
NAME AND FUNCTION
1, 2, 3
A, B, C
Data Inputs
4, 5
G2A G2B
Enable Input (Active
LOW)
6
G1
Data Enable Input
(Active HIGH)
15, 14, 13,
12, 11, 10, 9,
7
Y0 to Y7
Outputs
8
GND
Ground (0V)
16
V
CC
Positive Supply Voltage
IEC LOGIC SYMBOLS
INPUT AND OUTPUT EQUIVALENT CIRCUIT
M54/M74HC238
2/10
LOGIC DIAGRAM
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
M54/M74HC238
3/10
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
2 to 6
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
= 2 V
0 to 1000
ns
V
CC
= 4.5 V
0 to 500
V
CC
= 6 V
0 to 400
DC SPECIFICATIONS
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.
V
IH
High Level Input
Voltage
2.0
1.5
1.5
1.5
V
4.5
3.15
3.15
3.15
6.0
4.2
4.2
4.2
V
IL
Low Level Input
Voltage
2.0
0.5
0.5
0.5
V
4.5
1.35
1.35
1.35
6.0
1.8
1.8
1.8
V
OH
High Level
Output Voltage
2.0
V
I
=
V
IH
or
V
IL
I
O
=-20
A
1.9
2.0
1.9
1.9
V
4.5
4.4
4.5
4.4
4.4
6.0
5.9
6.0
5.9
5.9
4.5
I
O
=-4.0 mA
4.18
4.31
4.13
4.10
6.0
I
O
=-5.2 mA
5.68
5.8
5.63
5.60
V
OL
Low Level Output
Voltage
2.0
V
I
=
V
IH
or
V
IL
I
O
= 20
A
0.0
0.1
0.1
0.1
V
4.5
0.0
0.1
0.1
0.1
6.0
0.0
0.1
0.1
0.1
4.5
I
O
= 4.0 mA
0.17
0.26
0.33
0.40
6.0
I
O
= 5.2 mA
0.18
0.26
0.33
0.40
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND
0.1
1
1
A
I
CC
Quiescent Supply
Current
6.0
V
I
= V
CC
or GND
4
40
80
A
M54/M74HC238
4/10
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
2.0
30
75
95
110
ns
4.5
8
15
19
22
6.0
7
13
16
19
t
PLH
t
PHL
Propagation
Delay Time
(A, B, C - Y)
2.0
50
150
190
225
ns
4.5
17
30
38
45
6.0
15
26
32
38
t
PLH
t
PHL
Propagation
Delay Time
(G1 - Y)
2.0
50
150
190
225
ns
4.5
17
30
38
45
6.0
15
26
32
38
t
PLH
t
PHL
Propagation
Delay Time
(G2 - Y)
2.0
50
150
190
225
ns
4.5
17
30
38
45
6.0
15
26
32
38
C
IN
Input Capacitance
5
10
10
10
pF
C
PD
(*)
Power Dissipation
Capacitance
53
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/M74HC238
5/10
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