Datasheet

UNISONIC TECHNOLOGIES CO., LTD
U74HCT138
CMOS IC
3-TO-8 LINE DECODERS /
DEMULTIPLEXERS

SOP-16
DESCRIPTION
The U74HCT138 decodes a three−bit Address to 1−of−8
active−low outputs.
This device features three Chip Select inputs, two active−low and
one active−high, to facilitate the demultiplexing, cascading and
chip−selecting functions.
The demultiplexing function is accomplished by using the
Address inputs to select the desired device output. One of the Chip
Selects is used as a data input while the other Chip Selects are held
in their active states.

SSOP-16
TSSOP-16
FEATURES
* Operate from 4.5V to 5.5V
* Low Input Current:1.0uA Max
* Low Power Consumption: 8μA Max
* Typical tPD=15ns
* Inputs are TTL voltage compatible

ORDERING INFORMATION
Ordering Number
Lead Free
Halogen Free
U74HCT138L-S16-T
U74HCT138G-S16-T
U74HCT138L-S16-R
U74HCT138G-S16-R
U74HCT138L-R16-T
U74HCT138G-R16-T
U74HCT138L-R16-R
U74HCT138G-R16-R
U74HCT138L-P16-T
U74HCT138G-P16-T
U74HCT138L-P16-R
U74HCT138G-P16-R
www.unisonic.com.tw
Copyright © 2014 Unisonic Technologies Co., Ltd
Package
Packing
SOP-16
SOP-16
SSOP-16
SSOP-16
TSSOP-16
TSSOP-16
Tube
Tape Reel
Tube
Tape Reel
Tube
Tape Reel
1 of 5
QW-R502-642.B
U74HCT138


CMOS IC
PIN CONFIGURATION
A0
1
16 VCC
A1
2
15 Y0
A2
3
14 Y1
E1
4
13 Y2
E2
5
12 Y3
E3
6
11 Y4
Y7
7
10 Y5
GND
8
9
Y6
FUNCTION TABLE
INPUTS
E1
E2
E3
A0
H
X
X
X
X
H
X
X
X
X
L
X
L
L
H
L
L
L
H
H
L
L
H
L
L
L
H
H
L
L
H
L
L
L
H
H
L
L
H
L
L
L
H
H
Note:H : High voltage level
OUTPUTS
A1
A2
Y0
X
X
H
X
X
H
X
X
H
L
L
L
L
L
H
H
L
H
H
L
H
L
H
H
L
H
H
H
H
H
H
H
H
L : Low voltage level
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
Y1
Y2
H
H
H
H
H
H
H
H
L
H
H
L
H
H
H
H
H
H
H
H
H
H
X : Don’t care
Y3
Y4
Y5
Y6
Y7
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
H
H
H
H
H
H
L
2 of 5
QW-R502-642.B
U74HCT138

LOGIC SYMBOL

LOGIC DIAGRAM
E1
CMOS IC
Y0
E2
E3
Y1
Y2
Y3
Y4
A0
Y5
Y6
A1
Y7
A2
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
3 of 5
QW-R502-642.B
U74HCT138

CMOS IC
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Voltage
VCC
-0.5 ~ 7.0
V
Input Clamp Current(VI<0 or VI>VCC)
IIK
±20
mA
Output Clamp Current(VO<0 or VO>VCC)
IOK
±20
mA
Continuous Output Current(VO=0 to VCC)
IO
±25
mA
VCC or GND Current
ICC
±50
mA
Storage Temperature
TSTG
-65 ~ + 150
℃
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

RECOMMENDED OPERATING CONDITIONS
PARAMETER
Supply Voltage
Input Voltage
Output Voltage
Operating Temperature
Input Rise or Fall Times

SYMBOL
VCC
VIN
VOUT
TA
tR, tF
Junction to Ambient
SYMBOL
SOP-16
TSSOP-16
UNIT
°C/W
ELECTRICAL CHARACTERISTICS(TA=25°C)
SYMBOL
VIH
VIL
High-Level Output Voltage
VOH
Low-Level Output Voltage
VOL
Input Leakage Current
Quiescent Supply Current
II(LEAK)
ICC
Additional Quiescent Supply Current
△ICC
Input Capacitance
CI
TEST CONDITIONS
VCC=4.5V~5.5V
VCC=4.5V~5.5V
VCC=4.5V, IOH=-20μA
VCC=4.5V, IOH=-4mA
VCC=4.5V, IOL=20μA
VCC=4.5V, IOL=4mA
VCC=5.5V, VIN= VCC or GND
VCC=5.5V, VIN=VCC or GND, IOUT=0
One input at 0.5V or 2.4V,other
inputs at 0 or Vcc
VCC=4.5V~5.5V
MIN TYP MAX UNIT
2.0
V
0.8
V
4.4 4.499
V
3.98 4.3
V
0.001 0.1
V
0.17 0.26
V
±0.1 ±100 nA
8
μA
1.4
2.4
mA
3
10
pF
SWITCHING CHARACTERISTICS(TA=25°C, see TEST CIRCUIT AND WAVEFORMS)
PARAMETER
Propagation delay from input
(An) to output( Yn )
Propagation delay from input
( En ) to output( Yn )
Output Transition Time

RATINGS
73
108
θJA
PARAMETER
High-Level input voltage
Low-Lever output voltage

VCC=4.5V~5.5V
MIN TYP MAX UNIT
4.5 5.0 5.5
V
0
VCC
V
0
VCC
V
-40
+85
°C
500
ns
THERMAL CHARACTERISTICS
PARAMETER

TEST CONDITIONS
Operating
SYMBOL
tPLH/tPHL
tPLH/tPHL
tTLH/tTHL
TEST CONDITIONS
VCC =4.5V, CL=50pF
VCC =5.5V, CL=50pF
VCC =4.5V, CL=50pF
VCC =5.5V, CL=50pF
VCC =4.5V, CL=50pF
VCC =5.5V, CL=50pF
MIN TYP MAX UNIT
23
36
ns
17
32
ns
22
33
ns
18
30
ns
12
15
ns
11
14
ns
OPERATING CHARACTERISTICS
PARAMETER
Power Dissipation Capacitance
SYMBOL
CPD
TEST CONDITIONS
No load
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP MAX UNIT
85
pF
4 of 5
QW-R502-642.B
U74HCT138

CMOS IC
TEST CIRCUIT AND WAVEFORMS
Test Circuit
3V
1.3V
Input
1.3V
tPHL
Output
90%
90%
1.3V
10%
VOH
1.3V
10%
VOL
tTLH
tTHL
tTLH
Output
GND
tPLH
tTHL
90%
1.3V
10%
VOH
90%
1.3V
10%
VOL
tPHL
tPLH
Propagation Delay and Output Tansition Times
Note: CL includes probe and jig capacitance.
All input pulses are supplied by generators having the following characteristics: Zo = 50Ω, tR =6ns, tF =6ns.
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
5 of 5
QW-R502-642.B