TI SN74AHCT138N

SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
D
D
D
D
description
The ’AHCT138 3-line to 8-line decoders/
demultiplexers are designed to be used in
high-performance
memory-decoding
and
data-routing applications that require very short
propagation-delay times. In high-performance
memory systems, this decoder can be used to
minimize the effects of system decoding. When
employed with high-speed memories utilizing a
fast enable circuit, the delay times of this decoder
and the enable time of the memory usually are
less than the typical access time of the memory.
This means that the effective system delay
introduced by the decoder is negligible.
SN54AHCT138 . . . J OR W PACKAGE
SN74AHCT138 . . . D, DB, DGV, N, OR PW PACKAGE
(TOP VIEW)
A
B
C
G2A
G2B
G1
Y7
GND
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
Y0
Y1
Y2
Y3
Y4
Y5
Y6
SN54AHCT138 . . . FK PACKAGE
(TOP VIEW)
B
A
NC
VCC
Y0
D
D
EPIC  (Enhanced-Performance Implanted
CMOS) Process
Inputs Are TTL-Voltage Compatible
Designed Specifically for High-Speed
Memory Decoders and Data-Transmission
Systems
Incorporate Three Enable Inputs to Simplify
Cascading and/or Data Reception
Latch-Up Performance Exceeds 250 mA Per
JESD 17
ESD Protection Exceeds 2000 V Per
MIL-STD-833, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
Package Options Include Plastic
Small-Outline (D), Shrink Small-Outline
(DB), Thin Very Small-Outline (DGV), Thin
Shrink Small-Outline (PW), and Ceramic
Flat (W) Packages, Ceramic Chip Carriers
(FK), and Standard Plastic (N) and Ceramic
(J) DIPs
C
G2A
NC
G2B
G1
4
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
Y1
Y2
NC
Y3
Y4
Y7
GND
NC
Y6
Y5
D
NC – No internal connection
The conditions at the binary-select inputs and the three enable inputs select one of eight output lines. Two
active-low and one active-high enable inputs reduce the need for external gates or inverters when expanding.
A 24-line decoder can be implemented without external inverters and a 32-line decoder requires only one
inverter. An enable input can be used as a data input for demultiplexing applications.
The SN54AHCT138 is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74AHCT138 is characterized for operation from –40°C to 85°C.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
EPIC is a trademark of Texas Instruments Incorporated.
Copyright  2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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1
SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
FUNCTION TABLE
ENABLE INPUTS
G1
G2A
X
X
SELECT INPUTS
G2B
C
B
H
X
X
X
H
X
OUTPUTS
A
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
X
X
H
H
H
H
H
H
H
H
X
X
H
H
H
H
H
H
H
H
L
X
X
X
X
X
H
H
H
H
H
H
H
H
H
L
L
L
L
L
L
H
H
H
H
H
H
H
H
L
L
L
L
H
H
L
H
H
H
H
H
H
H
L
L
L
H
L
H
H
L
H
H
H
H
H
H
L
L
L
H
H
H
H
H
L
H
H
H
H
H
L
L
H
L
L
H
H
H
H
L
H
H
H
H
L
L
H
L
H
H
H
H
H
H
L
H
H
H
L
L
H
H
L
H
H
H
H
H
H
L
H
H
L
L
H
H
H
H
H
H
H
H
H
H
L
logic symbols (alternatives)†
A
B
C
G1
1
2
3
6
4
G2A
G2B
5
BIN/OCT
0
1
2
1
4
2
3
&
4
EN
5
6
7
15
14
13
12
11
10
9
7
Y0
Y1
Y2
A
B
C
1
G1
Y5
G2A
Y6
G2B
3
6
4
5
Y7
POST OFFICE BOX 655303
0
G
7
2
1
2
&
3
4
5
6
7
† These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, DB, DGV, J, N, PW, and W packages.
2
0
2
Y3
Y4
DMUX
0
• DALLAS, TEXAS 75265
15
14
13
12
11
10
9
7
Y0
Y1
Y2
Y3
Y4
Y5
Y6
Y7
SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
logic diagram (positive logic)
15
Y0
A
1
14
Y1
13
Select
Inputs
B
Y2
2
12
Y3
11
3
Data
Outputs
Y4
C
10
Y5
9
Y6
4
G2A
Enable
Inputs
G2B
7
5
Y7
6
G1
Pin numbers shown are for the D, DB, DGV, J, N, PW, and W packages.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Input voltage range, VI (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Output voltage range, VO (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to VCC + 0.5 V
Input clamp current, IIK (VI < 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –20 mA
Output clamp current, IOK (VO < 0 or VO > VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±20 mA
Continuous output current, IO (VO = 0 to VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25 mA
Continuous current through VCC or GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±75 mA
Package thermal impedance, θJA (see Note 2): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73°C/W
DB package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82°C/W
DGV package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W
N package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67°C/W
PW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. The package thermal impedance is calculated in accordance with JESD 51.
POST OFFICE BOX 655303
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3
SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
recommended operating conditions (see Note 3)
SN54AHCT138
SN74AHCT138
MIN
MAX
MIN
MAX
4.5
5.5
4.5
5.5
UNIT
VCC
VIH
Supply voltage
VIL
VI
Low-level input voltage
0.8
V
Input voltage
0
5.5
0
5.5
V
VO
IOH
Output voltage
0
0
VCC
–8
V
High-level output current
VCC
–8
mA
IOL
∆t/∆v
Low-level output current
8
8
mA
20
20
ns/V
High-level input voltage
2
2
0.8
Input transition rise or fall rate
V
V
TA
Operating free-air temperature
–55
125
–40
85
°C
NOTE 3: All unused inputs of the device must be held at VCC or GND to ensure proper device operation. Refer to the TI application report,
Implications of Slow or Floating CMOS Inputs, literature number SCBA004.
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
VCC
VOH
IOH = –50 mA
IOH = –8 mA
45V
4.5
VOL
IOL = 50 mA
IOL = 8 mA
45V
4.5
II
ICC
VI = VCC or GND
VI = VCC or GND,
IO = 0
5.5 V
∆ICC†
One input at 3.4 V,
Other inputs at VCC or GND
5.5 V
0 V to 5.5 V
MIN
4.4
TA = 25°C
TYP
MAX
4.5
3.94
SN54AHCT138
MIN
MAX
SN74AHCT138
MIN
4.4
4.4
3.8
3.8
POST OFFICE BOX 655303
UNIT
V
0.1
0.1
0.1
0.36
0.5
0.44
±0.1
±1*
±1
mA
4
40
40
mA
1.35
1.5
1.5
mA
10
pF
Ci
VI = VCC or GND
5V
2
10
* On products compliant to MIL-PRF-38535, this parameter is not production tested at VCC = 0 V.
† This is the increase in supply current for each input at one of the specified TTL voltage levels rather than 0 V or VCC.
4
MAX
• DALLAS, TEXAS 75265
V
SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
switching characteristics over recommended operating free-air temperature range,
VCC = 5 V ± 0.5 V (unless otherwise noted) (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
LOAD
CAPACITANCE
tPLH
tPHL
A B
A,
B, C
Any Y
CL = 15 pF
tPLH
tPHL
G1
Any Y
CL = 15 pF
tPLH
tPHL
G2A G2B
G2A,
Any Y
CL = 15 pF
tPLH
tPHL
A B
A,
B, C
Any Y
CL = 50 pF
tPLH
tPHL
G1
Any Y
CL = 50 pF
tPLH
tPHL
G2A G2B
G2A,
Any Y
CL = 50 pF
MIN
TA = 25°C
TYP
MAX
SN54AHCT138
SN74AHCT138
MIN
MAX
MIN
MAX
7.6*
10.4*
1*
12*
1
12
7.6*
10.4*
1*
12*
1
12
6.6*
9.1*
1*
10.5*
1
10.5
6.6*
9.1*
1*
10.5*
1
10.5
7*
9.6*
1*
11*
1
11
7*
9.6*
1*
11*
1
11
8.1
11.4
1
13
1
13
8.1
11.4
1
13
1
13
7.1
10.1
1
11.5
1
11.5
7.1
10.1
1
11.5
1
11.5
7.5
10.6
1
12
1
12
7.5
10.6
1
12
1
12
TEST CONDITIONS
TYP
UNIT
ns
ns
ns
ns
ns
ns
* On products compliant to MIL-PRF-38535, this parameter is not production tested.
operating characteristics, VCC = 5 V, TA = 25°C
PARAMETER
Cpd
Power dissipation capacitance
No load,
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f = 1 MHz
14
UNIT
pF
5
SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
PARAMETER MEASUREMENT INFORMATION
Test
Point
From Output
Under Test
RL = 1 kΩ
From Output
Under Test
VCC
Open
S1
TEST
GND
CL
(see Note A)
CL
(see Note A)
S1
tPLH/tPHL
tPLZ/tPZL
tPHZ/tPZH
Open Drain
Open
VCC
GND
VCC
LOAD CIRCUIT FOR
3-STATE AND OPEN-DRAIN OUTPUTS
LOAD CIRCUIT FOR
TOTEM-POLE OUTPUTS
3V
1.5 V
Timing Input
0V
tw
3V
1.5 V
Input
1.5 V
th
tsu
3V
1.5 V
Data Input
1.5 V
0V
0V
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
3V
1.5 V
Input
1.5 V
0V
tPLH
In-Phase
Output
tPHL
50% VCC
tPHL
Out-of-Phase
Output
VOH
50% VCC
VOL
Output
Waveform 1
S1 at VCC
(see Note B)
VOH
50% VCC
VOL
1.5 V
tPLZ
≈VCC
50% VCC
Output
Waveform 2
S1 at GND
(see Note B)
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
1.5 V
0V
tPZL
tPZH
tPLH
50% VCC
3V
Output
Control
VOL + 0.3 V
VOL
tPHZ
50% VCC
VOH – 0.3 V
VOH
≈0 V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR ≤ 1 MHz, ZO = 50 Ω, tr ≤ 3 ns, tf ≤ 3 ns.
D. The outputs are measured one at a time with one input transition per measurement.
Figure 1. Load Circuit and Voltage Waveforms
6
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SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
APPLICATION INFORMATION
SN74AHCT138
BIN/OCT
1
2
3
VCC
0
1
1
2
2
4
6
3
&
4
4
EN
5
5
6
7
15
14
13
12
11
10
9
7
0
1
2
3
4
5
6
7
SN74AHCT138
BIN/OCT
1
A0
2
A1
3
A2
1
2
2
4
6
A3
0
1
3
&
4
4
A4
EN
5
5
6
7
15
14
13
12
11
10
9
7
8
9
10
11
12
13
14
15
SN74AHCT138
BIN/OCT
1
2
3
6
0
1
1
2
2
4
3
&
4
4
5
EN
5
6
7
15
14
13
12
11
10
9
7
16
17
18
19
20
21
22
23
Figure 2. 24-Bit Decoding Scheme
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SN54AHCT138, SN74AHCT138
3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
SCLS266J – DECEMBER 1995 – REVISED JANUARY 2000
APPLICATION INFORMATION
SN74AHCT138
BIN/OCT
1
A0
2
A1
3
A2
1
1
2
2
4
6
VCC
0
3
&
4
4
A3
EN
5
A4
5
6
7
15
14
13
12
11
10
9
7
0
1
2
3
4
5
6
7
SN74AHCT138
BIN/OCT
1
2
3
0
1
1
2
2
4
6
3
&
4
4
EN
5
5
6
7
15
14
13
12
11
10
9
7
8
9
10
11
12
13
14
15
SN74AHCT138
BIN/OCT
1
2
3
0
1
1
2
2
4
6
3
&
4
4
EN
5
5
6
7
15
14
13
12
11
10
9
7
16
17
18
19
20
21
22
23
SN74AHCT138
BIN/OCT
1
2
3
6
0
1
1
2
2
4
3
&
4
4
5
EN
5
6
7
Figure 3. 32-Bit Decoding Scheme
8
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15
14
13
12
11
10
9
7
24
25
26
27
28
29
30
31
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accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
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Copyright  2000, Texas Instruments Incorporated