The 74LCX138 is a low voltage CMOS 3 TO 8
LINE DECODER (INVERTING) fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology. It is ideal for low power
and high speed 3.3V applications; it can be
interfaced to 5V signal environment for inputs.
If the device is enabled, 3 binary select inputs (A,
B and C) determine which one of the o utputs will
TSSOPSOP
ORDER CODES
PACKAGETUBET & R
SOP74LCX138M74LCX138MTR
TSSOP74LCX138TTR
go low. If enable input G1 is held low or either G2A
or G2B is held high, the decoding function is
ihnibited and all the 8 outputs go to high.
Three enable inputs are provided to ease cascade
connection and application of address decoders
for memory systems.
It has same speed performance at 3. 3V than 5V
AC/ACT family, combined with a lower power
consumption.
All inputs and outputs are equipped with
protection circuits against stat ic discharge, giving
them 2KV ESD immunity and transient excess
voltage.
This log i c diagram has not be used to esti m ate propaga tion delays
ABSOLUTE MAXIMUM RATINGS
74LCX138
SymbolParameterValueUnit
V
V
V
V
I
I
OK
I
I
CC
I
GND
T
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) I
absolute ma xim um rating mu st be observed
O
2) V
< GND
O
Supply Voltage
CC
DC Input Voltage
I
DC Output Voltage (VCC = 0V)
O
DC Output Voltage (High or Low State) (note 1)-0.5 to VCC + 0.5
O
DC Input Diode Current
IK
DC Output Diode Current (note 2)
DC Output Current
O
DC Supply Current per Supply Pin
DC Ground Current per Supply Pin
Storage Temperature
stg
Lead Temperature (10 sec)
L
-0.5 to +7.0V
-0.5 to +7.0V
-0.5 to +7.0V
V
- 50mA
- 50mA
± 50mA
± 100mA
± 100mA
-65 to +150°C
300°C
RECOMMENDED OPERATING CONDITIONS
SymbolParameterValueUnit
V
V
V
V
I
OH
I
OH
T
dt/dvInput Rise and Fall Time (note 2)0 to 10ns/V
1) Truth T abl e guaranteed: 1.5V to 3.6V
2) V
from 0.8V to 2V at VCC = 3.0V
IN
Supply Voltage (note 1)
CC
Input Voltage
I
Output Voltage (VCC = 0V)
O
Output Voltage (High or Low State)0 to V
O
, I
High or Low Level Output Current (VCC = 3.0 to 3.6V)
OL
, I
High or Low Level Output Current (VCC = 2.7V)
OL
Operating Temperature
op
2.0 to 3.6V
0 to 5.5V
0 to 5.5V
CC
± 24mA
± 12mA
-55 to 125°C
V
3/9
Page 4
74LCX138
DC SPECIFICATIONS
Test ConditionValue
SymbolParameter
IH
IL
OH
OL
I
I
off
CC
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
Low Level Output
Voltage
Input Leakage
Current
Power Off Leakage
Current
Quiescent Supply
Current
ICC incr. per Input
V
V
V
V
I
I
CC
∆I
V
CC
(V)
2.7 to 3.6
2.7 to 3.6
2.7
3.0
2.7 to 3.6
2.7
3.0
2.7 to 3.6
0
2.7 to 3.6
2.7 to 3.6
-40 to 85 °C-55 to 125 °C
Min.Max.Min.Max.
2.02.0V
0.80.8V
=-100 µAVCC-0.2VCC-0.2
I
O
=-12 mA
I
O
I
=-18 mA
O
I
=-24 mA
O
=100 µA
I
O
I
=12 mA
O
I
=16 mA
O
I
=24 mA
O
= 0 to 5.5V
V
I
or VO = 5.5V
V
I
2.22.2
2.42.4
2.22.2
0.20.2
0.40.4
0.40.4
0.550.55
± 5± 5µA
VI = VCC or GND
V
or VO= 3.6 to 5.5V
I
VIH = VCC - 0.6V
± 10± 10
500500µA
Unit
1010µA
1010
µA
V
V
DYNAMIC SWITCHING CHARACTERISTICS
Test ConditionValue
T
SymbolParameter
V
OLP
V
OLV
1) Number of outputs d ef i ned as "n". Me asured with "n-1" output s switching from HIGH to LO W or LOW to HIGH. The remaini ng outpu t is
measur ed i n the LOW state.
Dynamic Low Level Quiet
Output (note 1)
V
3.3
CC
(V)
= 50pF
C
L
V
= 0V, VIH = 3.3V
IL
Min.Typ.Max.
= 25 °C
A
0.8
-0.8
Unit
V
4/9
Page 5
AC ELECTRICAL CHARACTERISTICS
Test ConditionValue
74LCX138
SymbolParameter
V
CC
(V)
t
PLH tPHL
t
PLH tPHL
t
PLH tPHL
t
OSLH
t
OSHL
1) Skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switching in the same direction, either HIGH or LOW (t
2) Param eter guaran te ed by design
Propagation Delay
Time A, B, C to Y
Propagation Delay
Time G1 to Y
Propagation Delay
Time G2
Output To Output
to Y
Skew Time (note1,
2)
2.7
3.0 to 3.61.56.71.56.7
2.7
3.0 to 3.61.55.81.55.8
2.7
3.0 to 3.61.56.51.56.5
3.0 to 3.6505002.51.01.0ns
OSLH
C
L
(pF)
505002.5
505002.5
505002.5
= | t
PLHm
- t
PLHn
R
(Ω)
|, t
L
OSHL
t
s
(ns)
= t
= | t
-40 to 85 °C-55 to 125 °C
r
Min.Max.Min.Max.
7.97.9
6.46.4
7.47.4
- t
PHLn
|)
PHLm
Unit
ns
ns
ns
CAPACITIVE CHARACTERISTICS
Test ConditionValue
T
SymbolParameter
C
C
1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without
load. (R ef er to Test Circui t). Averag e operating cu rrent can be obtained by the foll owing equat io n. I
Input Capacitance
IN
Power Dissipation Capacitance
PD
(note 1)
V
CC
(V)
3.3
VIN = 0 to V
3.3fIN = 10MHz
V
= 0 or V
IN
Min.Typ.Max.
CC
CC
CC(opr)
= 25 °C
A
Unit
6pF
42
= CPD x VCC x fIN + I
pF
CC
TEST CIRCUIT
CL = 50pF or equivalent (includes jig and p robe capacitance)
R
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