74AHC138
Document number: DS35482 Rev. 2 - 2
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Preliminary
74AHC138
3-TO-8 LINE DECODER DEMULTIPLEXER
Description
The 74AHC138 is an advanced high speed CMOS device.
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 E 1 and E 2
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
• Wide Supply Voltage Range from 2.0 V to 5.5 V
• Sinks or sources 8mA at Vcc = 4.5V
• CMOS low power consumption
• Schmitt Trigger Action at All Inputs
• Inputs accept up to 5.5 V
• 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
• SO16 Available in “Green” Molding Compound
(no Br, Sb)
• Lead-Free Finish; RoHS Compliant (Notes 1 & 2)
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 < 1000 ppm antimony compounds.
Click for Ordering Information
74AHC138
Document number: DS35482 Rev. 2 - 2
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Preliminary
74AHC138
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
74AHC138
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74AHC138
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 +0.5 V 20 mA
IO Continuous output current +/- 25 mA
ICC Continuous current through VCC 75 mA
IGND Continuous current through 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 2.0 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 = 3.0 V ± 0.3 V 100 ns/V
VCC = 5.0 V ± 0.5 V 20
TA Operating free-air temperature -40 +125 °C
Notes: 5. Unused inputs should be held at VCC or Ground.
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74AHC138
Electrical Characteristics (@TA = +25°C, unless otherwise specified.)
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
VIH High-level Input
Voltage
2.0V 1.5 1.5 1.5
V
3.0V 2.1 2.1 2.1
5.5V 3.85 3.85 3.85
VIL Low-level input
voltage
2.0V 0.5 0.5 0.5
V
3.0V 0.9 0.9 0.9
5.5V 1.65 1.65 1.65
VOH High Level
Output Voltage
IOH = -50 μA 2.0V 1.9 2.0 1.9 1.9
V
IOH = -50 μA 3.0V 2.9 3.0
2.9 2.9
IOH = -50 μA 4.5V 4.4 4.5
4.4 4.4
IOH = -4 mA 3.0V 2.58 2.48 2.40
IOH = -8 mA 4.5V 3.94
3.80 3.70
VOL Low-level Output
Voltage
IOL = 50 μA 2.0V 0.1 0.1 0.1
V
IOL = 50 μA 3.0V 0.1 0.1 0.1
IOL = 50 μA 4.5V 0.1 0.1 0.1
IOL = 4 mA 3.0V 0.36 0.44 0.55
IOL = 8 mA 4.5V 0.36 0.44 0.55
II Input Current VI =GND or 5.5 V 5.5V 0.1 ± 1 ± 2 μA
ICC Supply Current VI = GND or VCC
IO=0 A 5.5V 4.0 40 80 μA
Ci Input
Capacitance Vi = VCC or GND 5.5V 4.0 10 10 10 pF
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=15 pF
3.0 V to 3.6V 0.5 4.4 8.0 0.5 9.5 0.5 11.5
ns
4.5 V to 5.5 V 0.5 3.0 5.5 0.5 6.5 0.5 7.0
Figure 2
CL=50pF
3.0 V to 3.6V 0.5 6.2 11.5 0.5 13.0 0.5 14.5
4.5 V to 5.5 V 0.5 4.3 7.5 0.5 8.5 0.5 9.5
Propagation
Delay E3 to Yn
Figure 2
CL=15 pF
3.0 V to 3.6V 0.5 4.7 8.0 0.5 9.5 0.5 11.5
ns
4.5 V to 5.5 V 0.5 3.3 5.1 0.5 6.0 0.5 7.5
Figure 2
CL=50pF
3.0 V to 3.6V 0.5 6.8 11.5 0.5 13.0 0.5 14.5
4.5 V to 5.5 V 0.5 4.7 7.1 0.5 8.0 0.5 9.0
Propagation
Delay En to Yn
Figure 2
CL=15 pF
3.0 V to 3.6V 0.5 6.7 9.7 0.5 11.5 0.5 12.5
ns
4.5 V to 5.5 V 0.5 4.8 6.8 0.5 8.0 0.5 8.5
Figure 2
CL=50pF
3.0 V to 3.6V 0.5 9.6 13.2 0.5 15.0 0.5 16.5
4.5 V to 5.5 V 0.5 6.8 8.8 0.5 10.0 0.5 11.0
74AHC138
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74AHC138
Operating Characteristics (@TA = +25°C, unless otherwise specified.)
Parameter Test Conditions
VCC = 5 V Unit
TYP
Cpd Power dissipation capacitance f = 1 MHz all outputs switching-no load 18 pF
Parameter Measurement Information
Vcc Inputs VM C
L
VI t
r/tf
2.0V -6.0V VCC 6ns VCC/2 50pF
5.0V VCC 6ns VCC/2 15pF used for 5V typical test
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
Figure 1. Load Circuit and Voltage Waveforms
74AHC138
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74AHC138
Ordering Information
Device Package Code
Packaging
(Note 6)
7” Tape and Reel (Note 7
Quantity Part Number Suffix
74AHC138S16-13 S16 SO-16 2500/Tape & Reel -13
74AHC138T16-13 T16 TSSOP-16 2500/Tape & Reel -13
Notes: 6. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf
7. The taping orientation is located on our website at http://www.diodes.com/datasheets/ap02007.pdf
Marking Information
(1) SO-16, TSSOP-16
Part Number Package
74AHC138S16 SO-16
74AHC138T16 TSSOP-16
74AHC138
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74AHC138
Package Outline Dimensions (All Dimensions in mm)
Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.
(1) Package Type: SO-16
(2) Package Type: TSSOP-16
SOIC-16
Dim Min Max Typ
A - 1.75 -
A1 0.10 0.25 -
b 0.31 0.51 -
c 0.10 0.25 -
D 9.80 10.00 -
E 5.80 6.20 -
E1 3.80 4.00 -
e - - 1.27
L 0.40 1.27 -
Ø 0° 8° -
Ø1 5° 15° -
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
Θ 0° 8° -
Θ1 5° 15° -
Θ2 0° - -
All Dimensions in mm
DETAIL 'A'
SEATING PLANE
GAUGE PLANE
Ø
L
8X
Ø1
eb 16X
E
E/2
E1
E1/2
D
SEATING PLANE
A
A1
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
74AHC138
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74AHC138
Suggested Pad Layout
Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.
(1) Package Type: SO-16
(2) 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
74AHC138
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74AHC138
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