查询CD74AC238M96供应商
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
D
AC Types Feature 1.5-V to 5.5-V Operation
and Balanced Noise Immunity at 30% of the
M PACKAGE
(TOP VIEW)
Supply Voltage
D
Speed of Bipolar F, AS, and S, With
Significantly Reduced Power Consumption
D
Designed Specifically for High-Speed
Memory Decoders and Data-Transmission
Systems
D
Incorporates Three Enable Inputs to
Simplify Cascading and/or Data Reception
D
Balanced Propagation Delays
D
±24-mA Output Drive Current
G
2A
G
2B
G1
Y7
GND
A
1
2
B
3
C
4
5
6
7
8
16
15
14
13
12
11
10
V
CC
Y0
Y1
Y2
Y3
Y4
Y5
9
Y6
– Fanout to 15 F Devices
D
SCR-Latchup-Resistant CMOS Process and
Circuit Design
D
Exceeds 2-kV ESD Protection Per
MIL-STD-883, Method 3015
description/ordering information
The CD74AC238 decoder/demultiplexer is designed for 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 neg ligible.
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 (see Application
Information).
ORDERING INFORMATION
T
A
–55°C to 125°C SOIC – M Tape and reel CD74AC238M96 AC238M
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines
are available at www.ti.com/sc/package.
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.
PACKAGE
†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
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.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 2003, Texas Instruments Incorporated
1
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
FUNCTION TABLE
ENABLE INPUTS SELECT INPUTS OUTPUTS
G1 G2A G2B C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7
X H X X X X L L L L L L L L
X XHXXXLLLLLLLL
L XXXXXLLLLLLLL
H LLLLLHLLLLLLL
H LLLLHLHLLLLLL
H LLLHLLLHLLLLL
H LLLHHL LLHLLLL
H LLHLLLLLLHLLL
H LLHLHLLLLLHLL
H LLHHLLLLLLLHL
H L L H H H L L L L L L L H
logic diagram (positive logic)
1
A
15
14
Y0
Y1
Select
Inputs
Enable
Inputs
13
12
11
10
Y2
Y3
Data
Y4
Y5
9
Y6
7
Y7
Outputs
2
B
3
C
4
2A
G
5
G
2B
6
G1
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
∆t/∆v
Input transition rise or fall rate
ns/V
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage range, V
Input clamp current, I
Output clamp current, I
Continuous output current, I
Continuous current through V
Package thermal impedance, θ
Storage temperature range, T
†
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 51-7.
–0.5 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
(VI < 0 V or VI > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IK
(VO < 0 V or VO > VCC) (see Note 1) ±50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OK
(VO > 0 V or VO < VCC) ±50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
or GND ±200 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
(see Note 2) 73°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JA
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
†
recommended operating conditions (see Note 3)
TA = 25°C
MIN MAX MIN MAX MIN MAX
V
V
V
V
V
I
OH
I
OL
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,
Supply voltage 1.5 5.5 1.5 5.5 1.5 5.5 V
CC
VCC = 1.5 V 1.2 1.2 1.2
High-level input voltage
IH
Low-level input voltage
IL
Input voltage 0 V
I
Output voltage 0 V
O
High-level output current VCC = 4.5 V to 5.5 V –24 –24 –24 mA
Low-level output current VCC = 4.5 V to 5.5 V 24 24 24 mA
p
Implications of Slow or Floating CMOS Inputs, literature number SCBA004.
VCC = 3 V 2.1 2.1 2.1
VCC = 5.5 V 3.85 3.85 3.85
VCC = 1.5 V 0.3 0.3 0.3
VCC = 3 V
VCC = 5.5 V 1.65 1.65 1.65
VCC = 1.5 V to 3 V 50 50 50
VCC = 3.6 V to 5.5 V 20 20 20
–55°C to
125°C
0.9 0.9 0.9
CC
CC
0 V
0 V
CC
CC
–40°C to
85°C
0 V
0 V
CC
CC
UNIT
V
V
V
V
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
CD74AC238
CC
(INPUT)
(OUTPUT)
A, B, C
Any Y
ns
G1
Any Y
ns
G2A, G2B
Any Y
ns
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER TEST CONDITIONS V
1.5 V 1.4 1.4 1.4
IOH = –50 µA
V
OH
V
OL
I
I
I
CC
C
†
i
T est one output at a time, not exceeding 1-second duration. Measurement is made by forcing indicated current and measuring voltage to minimize
power dissipation. T est verifies a minimum 50-Ω transmission-line drive capability at 85°C and 75-Ω transmission-line drive capability at 125°C.
VI = VIH or V
VI = VIH or V
VI = VCC or GND 5.5 V ±0.1 ±1 ±1 µA
VI = VCC or GND, IO = 0 5.5 V 8 160 80 µA
IL
IL
IOH = –4 mA 3 V 2.58 2.4 2.48
IOH = –24 mA 4.5 V 3.94 3.7 3.8
IOH = –50 mA
IOH = –75 mA
IOL = 50 µA
IOL = 12 mA 3 V 0.36 0.5 0.44
IOL = 24 mA 4.5 V 0.36 0.5 0.44
IOL = 50 mA
IOL = 75 mA
†
†
†
†
3 V 2.9 2.9 2.9
4.5 V 4.4 4.4 4.4
5.5 V 3.85
5.5 V 3.85
1.5 V 0.1 0.1 0.1
3 V 0.1 0.1 0.1
4.5 V 0.1 0.1 0.1
5.5 V 1.65
5.5 V 1.65
TA = 25°C
MIN MAX MIN MAX MIN MAX
–55°C to
125°C
10 10 10 pF
–40°C to
85°C
UNIT
V
V
switching characteristics over recommended operating free-air temperature range,
V
= 1.5 V, CL = 50 pF (unless otherwise noted) (see Figure 1)
CC
PARAMETER
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
FROM
TO
–55°C to
125°C
MIN MAX MIN MAX
187 170
187 170
208 189
208 189
149 135
149 135
–40°C to
85°C
UNIT
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
(INPUT)
(OUTPUT)
A, B, C
Any Y
ns
G1
Any Y
ns
G2A, G2B
Any Y
ns
(INPUT)
(OUTPUT)
A, B, C
Any Y
ns
G1
Any Y
ns
G2A, G2B
Any Y
ns
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
switching characteristics over recommended operating free-air temperature range,
V
= 3.3 V ± 0.3 V, CL = 50 pF (unless otherwise noted) (see Figure 1)
CC
–55°C to
125°C
MIN MAX MIN MAX
5.3 21 5.4 19.1
5.3 21 5.4 19.1
5.8 23.2 6 21.1
5.8 23.2 6 21.1
4.2 16.7 4.3 15.2
4.2 16.7 4.3 15.2
PARAMETER
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
FROM
TO
switching characteristics over recommended operating free-air temperature range,
V
= 5 V ± 0.5 V, CL = 50 pF (unless otherwise noted) (see Figure 1)
CC
–55°C to
125°C
MIN MAX MIN MAX
3.8 15 3.9 13.6
3.8 15 3.9 13.6
4.2 16.6 4.3 15.1
4.2 16.6 4.3 15.1
3 11.9 3.1 10.7
3 11.9 3.1 10.7
PARAMETER
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
FROM
TO
–40°C to
85°C
–40°C to
85°C
CD74AC238
UNIT
UNIT
operating characteristics, VCC = 5 V, TA = 25°C
PARAMETER TYP UNIT
C
pd
Power dissipation capacitance 110 pF
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
PARAMETER MEASUREMENT INFORMATION
S1
50% V
t
r
CC
t
f
†
†
CC
t
rec
50% V
50% V
t
PHL
t
PLH
.
dis
CC
CC
50%
From Output
Under Test
CL = 50 pF
(see Note A)
†
When VCC = 1.5 V, R1 = R2 = 1 kΩ
CLR
Input
CLK
VOLTAGE WAVEFORMS
Input
In-Phase
Output
Out-of-Phase
Output
PROPAGATION DELAY AND OUTPUT TRANSITION TIMES
NOTES: A. CL includes probe and test-fixture capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low 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. For clock inputs, f
E. The outputs are measured one at a time with one input transition per measurement.
F. t
G. t
H. t
I. All parameters and waveforms are not applicable to all devices.
50% V
CC
t
PLH
50%
t
PHL
VOLTAGE WAVEFORMS
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
Phase relationships between waveforms are arbitrary.
and t
PLH
PZL
PLZ
and t
and t
PHL
PZH
PHZ
R1 = 500 Ω
R2 = 500 Ω
LOAD CIRCUIT
RECOVERY TIME
90% 90%
50% V
10% 10%
is measured with the input duty cycle at 50%.
max
are the same as tpd.
are the same as ten.
are the same as t
2 × V
Open
GND
50% V
10%10%
90%90%
V
0 V
V
0 V
CC
CC
CC
t
t
TEST S1
t
w
50% V
50% V
50% V
Open
2 × V
GND
CC
50% V
CC
t
h
CC
CC
CC
50% V
50% V
20% V
80% V
CC
50% V
10%10%
t
CC
t
PLZ
t
PHZ
V
0 V
f
CC
CC
CC
V
0 V
V
CC
0 V
V
CC
0 V
≈V
V
OL
V
OH
≈0 V
CC
CC
CC
t
PLH/tPHL
t
PLZ/tPZL
t
PHZ/tPZH
Input
Reference
Input
Data
Input
SETUP AND HOLD AND INPUT RISE AND FALL TIMES
V
CC
0 V
V
OH
CC
V
OL
f
V
OH
V
OL
r
Waveform 1
S1 at 2 × V
(see Note B)
Waveform 2
(see Note B)
50%
Output
Control
Output
Output
S1 at GND
OUTPUT ENABLE AND DISABLE TIMES
50% V
CC
VOLTAGE WAVEFORMS
PULSE DURATION
t
su
90% 90%
t
r
VOLTAGE WAVEFORMS
t
PZL
CC
t
PZH
VOLTAGE WAVEFORMS
Figure 1. Load Circuit and Voltage Waveforms
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
APPLICATION INFORMATION
CD74AC238
A0
A1
A2
A3
A4
1
2
3
V
CC
6
4
5
1
2
3
6
4
5
BIN/OCT
1
2
4
&
CD74AC238
BIN/OCT
1
2
4
&
EN
EN
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
15
14
13
12
11
10
15
14
13
12
11
10
0
1
2
3
4
5
9
6
7
7
8
9
10
11
12
13
9
14
7
15
CD74AC238
1
2
3
6
4
5
BIN/OCT
1
2
4
&
Figure 2. 24-Bit Decoding Scheme
EN
15
0
1
2
3
4
5
6
7
14
13
12
11
10
16
17
18
19
20
21
9
22
7
23
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
7
CD74AC238
3-LINE TO 8-LINE DECODER/DEMULTIPLEXER
SCHS331 – FEBRUARY 2003
APPLICATION INFORMATION
A0
A1
A2
V
CC
A3
A4
CD74AC238
1
2
3
6
4
5
1
2
3
6
4
5
BIN/OCT
1
2
4
&
CD74AC238
BIN/OCT
1
2
4
&
EN
EN
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
15
14
13
12
11
10
15
14
13
12
11
10
0
1
2
3
4
5
9
6
7
7
8
9
10
11
12
13
9
14
7
15
CD74AC238
1
2
3
6
4
5
1
2
3
6
4
5
BIN/OCT
1
2
4
&
CD74AC238
BIN/OCT
1
2
4
&
EN
EN
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
15
14
13
12
11
10
15
14
13
12
11
10
16
17
18
19
20
21
9
22
7
23
24
25
26
27
28
29
9
30
7
31
Figure 3. 32-Bit Decoding Scheme
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PACKAGE OPTION ADDENDUM
www.ti.com
30-Mar-2005
PACKAGING INFORMATION
Orderable Device Status
(1)
Package
Type
Package
Drawing
Pins Package
Qty
Eco Plan
CD74AC238M96 ACTIVE SOIC D 16 2500 Pb-Free
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
(RoHS)
(2)
Lead/Ball Finish MSL Peak Temp
CU NIPDAU Level-2-260C-1 YEAR/
Level-1-235C-UNLIM
(3)
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
IMPORTANT NOTICE
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