74AHCT138
Document number: DS35483 Rev. 2 - 2
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74AHCT138
3 TO 8 LINE DECODER DEMULTIPLEXER
Description
The 74AHCT138 is an advanced high speed CMOS device that is
designed to be pin compatable with 74LS low power Schottky types.
The device accepts a three bit binary weighted address on input pins
A0, A1 and A2 and when enabled will produce one active low output
with the remaining seven being high.
There are two active LOW enable inputs E1 and E2, and one active
HIGH enable input E3. The disabled device state results in all outputs
being high. The enable state occurs with E1 and E2 asserted low and
E3 asserted high.
The multiple enable lines allow for the parallel expansion of decoders
to create 4-to-16 line versions with no additional parts and 5-to-32
versions with the addition of a single inverter.
Features
Supply Voltage Range from 4.5V to 5.5V
Sinks or Sources 8mA at VCC = 4.5V
CMOS Low Power Consumption
Schmitt Trigger Action at All Inputs
Inputs Accept up to 6.0V
ESD Protection Tested per JESD 22
Exceeds 200-V Machine Model (A115-A)
Exceeds 2000-V Human Body Model (A114-A)
Exceeds 1000-V Charged Device Model (C101C)
Latch-Up Exceeds 250mA per JESD 78, Class II
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
Applications
Memory chip select decoding
Demultiplexing
Single line peripheral control
Allow simple serial bit streams from a microcontroller to control as
many peripheral lines as needed
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Click here for ordering information, located at the end of datasheet
74AHCT138
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74AHCT138
Pin Descriptions
Pin Number Pin Name Description
1 A0 Address Input 0
2 A1 Address Input 1
3 A2 Address Input 2
4 E1 Enable Input 1 (active LOW)
5 E2 Enable Input 2 (active LOW)
6 E3 Enable Input 3 (active HIGH)
7 Y7 Output 7 (active LOW)
8 GND Ground
9 Y6 Output 6 (active LOW)
10 Y5 Output 5 (active LOW)
11 Y4 Output 4 (active LOW)
12 Y3 Output 3 (active LOW)
13 Y2 Output 2 (active LOW)
14 Y1 Output 1 (active LOW)
15 Y0 Output o (active LOW)
16 VCC Supply Voltage
Function Table Diagram
Control Input Output
E1 E2 E3 A2 A1 A0 Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0
H X X X X X H H H H H H H H
X H X
X X L
L L H
L L L H H H H H H H L
L L H H H H H H H L H
L H L H H H H H L H H
L H H H H H H L H H H
H L L H H H L H H H H
H L H H H L H H H H H
H H L H L H H H H H H
H H H L H H H H H H H
74AHCT138
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Absolute Maximum Ratings (Note 4) (@TA = +25°C, unless otherwise specified.)
Symbol Description Rating Unit
ESD HBM Human Body Model ESD Protection 2 KV
ESD CDM Charged Device Model ESD Protection 1 KV
ESD MM Machine Model ESD Protection 200 V
VCC Supply Voltage Range -0.5 to +7.0 V
VI Input Voltage Range -0.5 to +7.0 V
Vo Voltage applied to output in high or low state -0.3 to VCC +0.5 V
IIK Input Clamp Current VI< -0.5V -20 mA
IOK Output Clamp Current VO<-0.5V -20 mA
IOK Output Clamp Current VO> VCC + 0.5V 25 mA
IO Continuous output current +/- 25 mA
ICC Continuous current through VDD or GND 75 mA
IGND Continuous current through VDD or GND -75 mA
TJ Operating Junction Temperature -40 to +150 °C
TSTG Storage Temperature -65 to +150 °C
PTOT Total Power Dissipation 500 mW
Notes: 4. Stresses beyond the absolute maximum may result in immediate failure or reduced reliability. These are stress values and device operation should be
within recommend values.
Recommended Operating Conditions (Note 5) (@TA = +25°C, unless otherwise specified.)
Symbol Parameter Conditions Min Max Unit
VCC Supply Voltage 4.5 5.5 V
VI Input Voltage 0 5.5 V
VO Output Voltage Active Mode 0 VCC V
t/V Input transition Rise or Fall Rate VCC = 4.5V to 5.5V 20 ns/V
TA Operating Free-Air Temperature -40 +125 °C
Note: 5. Unused inputs should be held at VCC or Ground.
Electrical Characteristics (@TA = +25°C, unless otherwise specified.)
Symbol Parameter Test Conditions VCC TA = +25°C TA = -40°C to +85°C TA = -40°C to +125°C Unit
Min Typ Max Min Max Min Max
VIH High-level Input
Voltage 4.5V to 5.5V 2.0 2.0 2.0 V
VIL Low-level input
voltage 4.5V to 5.5V 0.8 0.8 0.8 V
VOH High Level
Output Voltage
IOH = -50μA 4.5V 4.4 4.5
4.4 4.4 V
IOH = -8mA 4.5V 3.94
3.80 3.70
VOL Low-level Output
Voltage
IOL = 50μA 4.5V 0 0.1 0.1 0.1 V
IOL = 8mA 4.5V 0.36 0.44 0.55
II Input Current VI = GND or 5.5V 0V to 5.5V 0.1 ±0.1 ± 1 ± 2 μA
ICC Supply Current VI = GND or VCC
IO = 0 5.5V 4.0 40 80 μA
∆ICC
Additional
Supply Current
per Input
VI = Vcc -2.1V
IO = 0 4.5V to 5.5V 1.35 1.5 1.5 mA
Ci Input
Capacitance
Vi = VCC or GND 5.5V 4 10 10 10 pF
74AHCT138
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Switching Characteristics
Symbol Parameter Test Conditions VCC TA = +25°C -40°C to +85°C -40°C to +125°C Unit
Min Typ Max Min Max Min Max
tPD
Propagation Delay
An to Yn
Figure 2 CL =15pF 4.5V to 5.5V 0.5 4.4 10.4 1.0 12.0 1.0 13.0 ns
Figure 2 CL = 50pF 4.5V to 5.5V 0.5 6.2 11.4 1.0 13.0 1.0 14.5
Propagation Delay
E3 to Yn
Figure 2 CL = 15pF 4.5V to 5.5V 0.5 4.3 9.1 1.0 10.5 1.0 11.5 ns
Figure 2 CL = 50pF 4.5V to 5.5V 0.5 6.2 10.1 1.0 11.5 1.0 13.0
Propagation Delay
En to Yn
Figure 2 CL = 15pF 4.5V to 5.5V 0.5 4.3 9.6 1.0 11.0 1.0 12.0 ns
Figure 2 CL = 50pF 4.5V to 5.5V 0.5 6.2 10.6 1.0 12.0 1.0 13.5
Operating Characteristics (@TA = +25°C, unless otherwise specified.)
Parameter Test
Conditions VCC = 5V Unit
Typ
Cpd Power dissipation
capacitance f = 1 MHz all outputs switching-no load 23 pF
Parameter Measurement Information
VCC Inputs VM CL
VI t
r/tf Input Output
4.5V to 5.5V 3.0 V 3ns 1.5 V VCC/2 15pF, 50pF
Voltage Waveform
Pulse Duration
Voltage Waveform
Propagation Delay Times
Inverting and Non Inverting Outputs
Notes: A. Includes test lead and test apparatus capacitance.
B. All pulses are supplied at pulse repetition rate ≤ 10 MHz.
C. Inputs are measured separately one transition per measurement.
D. tPLH and tPHL are the same as tPD.
74AHCT138
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74AHCT138
Figure 1. Load Circuit and Voltage Waveforms
Ordering Information
Part Number Package Code Packaging 7” Tape and Reel (Note 7)
Quantity Part Number Suffix
74AHCT138S16-13 S16 SO-16 2500/Tape & Reel -13
74AHCT138T16-13 T16 TSSOP-16 2500/Tape & Reel -13
Notes: 7. The taping orientation is located on our website at http://www.diodes.com/datasheets/ap02007.pdf
Marking Information
(1) SO-16, TSSOP16
Part Number Package
74AHCT138S16 SO-16
74AHCT138T16 TSSOP-16
74AHCT138
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74AHCT138
Package Outline Dimensions (All dimensions in mm.)
Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.
Package Type: SO-16
Package Type: TSSOP-16
SO-16
Dim Min Max
A 1.40 1.75
A1 0.10 0.25
A2 1.30 1.50
B 0.33 0.51
C 0.19 0.25
D 9.80 10.00
E 3.80 4.00
e 1.27 Typ
H 5.80 6.20
L 0.38 1.27
Θ
0 8
All Dimensions in mm
TSSOP-16
Dim Min Max Typ
A - 1.08 -
A1 0.05 0.15 -
A2 0.80 0.93 -
b 0.19 0.30 -
c 0.09 0.20 -
D 4.90 5.10 -
E 6.40 BSC
E1 4.30 4.50 -
e 0.65 BSC
L 0.45 0.75 -
L1 1.00 REF
L2 0.25 BSC
R 0.09 - -
R1 0.09 - -
X - - 1.350
Y - - 1.050
Θ0° 8° -
Θ1 5° 15° -
Θ2 0° - -
All Dimensions in mm
D
EH
L
A2
BeA1
A
C
Detail ‘A’
Detail ‘A’
Gauge Plane
PIN 1
eb
E
E/2
E1
A2
A
D
A1
X
Y
SEE DETAIL 'A'
SEATING PLANE
GAUGE
PLANE
R
L
L1
L2
Ø0.760Depth0.050±0.02
R1
x)
C
DETAIL 'A'
74AHCT138
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Suggested Pad Layout
Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.
Package Type: SO-16
Package Type: TSSOP-16
Dimensions Value (in mm)
C 1.270
X 0.670
X1 9.560
Y 1.450
Y1 6.400
Dimensions Value (in mm)
C 0.650
X 0.350
X1 4.900
Y 1.400
Y1 6.800
X1
XC
Y
Y1
Pin 1
X1
Y (16x)
Y1
X (16x)
1
C
74AHCT138
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74AHCT138
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