SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
EPIC
(Enhanced-Performance Implanted
CMOS) Submicron Process
D
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D
Latch-Up Performance Exceeds 250 mA Per
JESD 17
D
Typical VOLP (Output Ground Bounce)
< 0.8 V at VCC = 3.3 V, TA = 25°C
D
Typical VOHV (Output VOH Undershoot)
> 2 V at VCC = 3.3 V, TA = 25°C
D
Inputs Accept Voltages to 5.5 V
D
Package Options Include Plastic
Small-Outline (D), Shrink Small-Outline
(DB), and Thin Shrink Small-Outline (PW)
Packages
description
This quadruple 2-line to 1-line data selector/multiplexer is designed for 1.65-V to 3.6-V VCC operation.
The SN74LVC257A is designed to multiplex signals from 4-bit data sources to 4-output data lines in
bus-organized systems. The 3-state outputs do not load the data lines when the output-enable (OE) input is at
a high logic level.
Inputs can be driven from either 3.3-V or 5-V devices. This feature allows the use of these devices as translators
in a mixed 3.3-V/5-V system environment.
T o ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN74LVC257A is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
INPUTS OUTPUT
OE A/B A B Y
H X X X Z
LLLX L
LLHX H
LHXL L
LHXH H
Copyright 1998, 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.
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.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
A/B
1A
1B
1Y
2A
2B
2Y
GND
VCC
OE
4A
4B
4Y
3A
3B
3Y
D, DB, OR PW PACKAGE
(TOP VIEW)
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
2POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol†
2
1A
1
3
1B 5
2A 6
2B 11
3A 10
3B 14
4A 13
4B
EN
15
G1
1
MUX
11Y
4
2Y
7
3Y
9
4Y
12
OE
A/B
†This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
logic diagram (positive logic)
4Y
3Y
2Y
1Y
A/B
OE
4B
4A
3B
3A
2B
2A
1B
1A 4
2
3
7
5
6
9
11
10
12
14
13
1
15
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage range, VCC –0.5 V to 6.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range, VI (see Note 1) –0.5 V to 6.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage range, VO (see Notes 1 and 2) –0.5 V to VCC + 0.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input clamp current, IIK (VI < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output clamp current, IOK (VO < 0) –50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous output current, IO ±50 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous current through VCC or GND ±100 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package thermal impedance, θJA (see Note 3): D package 113°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DB package 131°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PW package 149°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 af fect device reliability.
NOTES: 1. The input negative-voltage and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. The value of VCC is provided in the recommended operating conditions table.
3. The package thermal impedance is calculated in accordance with JESD 51.
recommended operating conditions (see Note 4)
MIN MAX UNIT
VCC
Su
pp
ly voltage
Operating 1.65 3.6
V
V
CC
S
u
ppl
y v
oltage
Data retention only 1.5
V
VCC = 1.65 V to 1.95 V 0.65 ×VCC
VIH High-level input voltage VCC = 2.3 V to 2.7 V 1.7 V
VCC = 2.7 V to 3.6 V 2
VCC = 1.65 V to 1.95 V 0.35 ×VCC
VIL Low-level input voltage VCC = 2.3 V to 2.7 V 0.7 V
VCC = 2.7 V to 3.6 V 0.8
VIInput voltage 0 5.5 V
VOOutput voltage 0 VCC V
VCC = 1.65 V –4
IOH
High level out
p
ut current
VCC = 2.3 V –8
mA
I
OH
High
-
le
v
el
o
u
tp
u
t
c
u
rrent
VCC = 2.7 V –12
mA
VCC = 3 V –24
VCC = 1.65 V 4
IOL
Low level out
p
ut current
VCC = 2.3 V 8
mA
I
OL
Lo
w-
le
v
el
o
u
tp
u
t
c
u
rrent
VCC = 2.7 V 12
mA
VCC = 3 V 24
∆t/∆vInput transition rise or fall rate 0 10 ns/V
TAOperating free-air temperature –40 85 °C
NOTE 4: 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.
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
4POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER TEST CONDITIONS VCC MIN TYP†MAX UNIT
IOH = –100 µA1.65 V to 3.6 V VCC–0.2
IOH = –4 mA 1.65 V 1.2
VOH
IOH = –8 mA 2.3 V 1.7
V
V
OH
IOH =12mA
2.7 V 2.2
V
I
OH = –
12
mA
3 V 2.4
IOH = –24 mA 3 V 2.2
IOL = 100 µA1.65 V to 3.6 V 0.2
IOL = 4 mA 1.65 V 0.45
VOL IOL = 8 mA 2.3 V 0.7 V
IOL = 12 mA 2.7 V 0.4
IOL = 24 mA 3 V 0.55
IIVI = 5.5 V or GND 3.6 V ±5µA
IOZ VO = VCC or GND 3.6 V ±10 µA
ICC VI = VCC or GND, IO = 0 3.6 V 10 µA
∆ICC One input at VCC – 0.6 V,
Other inputs at VCC or GND 2.7 V to 3.6 V 500 µA
CiVI = VCC or GND 3.3 V 5 pF
CoVO = VCC or GND 3.3 V 5 pF
†All typical values are at VCC = 3.3 V, TA = 25°C.
switching characteristics over recommended operating free-air temperature range (unless
otherwise noted) (see Figures 1 through 3)
PARAMETER FROM
(INPUT)
TO
(OUTPUT)
VCC = 1.8 V VCC = 2.5 V
± 0.2 V VCC = 2.7 V VCC = 3.3 V
± 0.3 V UNIT
(INPUT)
(OUTPUT)
TYP MIN MAX MIN MAX MIN MAX
td
A or B
Y
13.4 1 7.4 5.4 1 4.6
ns
t
pd A/B
Y
15.5 1 9.5 7.5 1 6.4
ns
ten OE Y 14.7 1 8.7 6.7 1 5.6 ns
tdis OE Y 12.7 1 6.7 4.7 1 4.3 ns
tsk(o)‡1ns
‡Skew between any two outputs of the same package switching in the same direction
operating characteristics, TA = 25°C
PARAMETER
TEST VCC = 1.8 V VCC = 2.5 V VCC = 3.3 V
UNIT
PARAMETER
CONDITIONS TYP TYP TYP
UNIT
Cpd Power dissipation capacitance f = 10 MHz 13.5 14.5 15.5 pF
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
VCC = 1.8 V ± 0.15 V
VCC/2
VCC/2
VCC/2VCC/2
VCC/2VCC/2
VCC/2
VCC/2
VOH
VOL
th
tsu
From Output
Under Test
CL = 30 pF
(see Note A)
LOAD CIRCUIT
S1 Open
GND
1 kΩ
1 kΩ
Output
Control
(low-level
enabling)
Output
W aveform 1
S1 at 2 × VCC
(see Note B)
Output
W aveform 2
S1 at Open
(see Note B)
tPZL
tPZH
tPLZ
tPHZ
0 V
VOL + 0.15 V
VOH – 0.15 V
0 V
VCC
0 V
0 V
tw
VCC VCC
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
Timing
Input
Data
Input
Input
tpd
tPLZ/tPZL
tPHZ/tPZH
Open
2 × VCC
Open
TEST S1
NOTES: A. CL includes probe and jig capacitance.
B. W aveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
W aveform 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 ≤10 MHz, ZO = 50 Ω, tr ≤2 ns, tf ≤2 ns.
D. The outputs are measured one at a time with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd.
0 V
VCC
VCC/2
tPHL
VCC/2 VCC/2 VCC
0 V
VOH
VOL
Input
Output
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VCC/2 VCC/2
tPLH
2 × VCC
VCC
Figure 1. Load Circuit and Voltage Waveforms
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
6POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
VCC = 2.5 V ± 0.2 V
VCC/2
VCC/2
VCC/2VCC/2
VCC/2VCC/2
VCC/2
VCC/2
VOH
VOL
th
tsu
From Output
Under Test
CL = 30 pF
(see Note A)
LOAD CIRCUIT
S1 Open
GND
500 Ω
500 Ω
Output
Control
(low-level
enabling)
Output
W aveform 1
S1 at 2 × VCC
(see Note B)
Output
W aveform 2
S1 at GND
(see Note B)
tPZL
tPZH
tPLZ
tPHZ
0 V
VOL + 0.15 V
VOH – 0.15 V
0 V
VCC
0 V
0 V
tw
VCC VCC
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
Timing
Input
Data
Input
Input
tpd
tPLZ/tPZL
tPHZ/tPZH
Open
2 × VCC
GND
TEST S1
NOTES: A. CL includes probe and jig capacitance.
B. W aveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
W aveform 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 ≤10 MHz, ZO = 50 Ω, tr ≤2 ns, tf ≤2 ns.
D. The outputs are measured one at a time with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd.
0 V
VCC
VCC/2
tPHL
VCC/2 VCC/2 VCC
0 V
VOH
VOL
Input
Output
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VCC/2 VCC/2
tPLH
2 × VCC
VCC
Figure 2. Load Circuit and Voltage Waveforms
SN74LVC257A
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER
WITH 3-STATE OUTPUTS
SCAS294G – JANUARY 1993 – REVISED OCT OBER 1998
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
VCC = 2.7 V AND 3.3 V ± 0.3 V
VOH
VOL
th
tsu
From Output
Under Test
CL = 50 pF
(see Note A)
LOAD CIRCUIT
S1
6 V
Open
GND
500 Ω
500 Ω
tPLH tPHL
Output
Control
(low-level
enabling)
Output
W aveform 1
S1 at 6 V
(see Note B)
Output
W aveform 2
S1 at GND
(see Note B)
tPZL
tPZH
tPLZ
tPHZ
1.5 V1.5 V
1.5 V 1.5 V 2.7 V
0 V
1.5 V 1.5 V VOH
VOL
0 V
1.5 V VOL + 0.3 V
1.5 V VOH – 0.3 V
0 V
1.5 V 2.7 V
0 V
1.5 V 1.5 V 0 V
2.7 V
0 V
1.5 V 1.5 V
tw
Input
2.7 V 2.7 V
3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
Timing
Input
Data
Input
Output
Input
tpd
tPLZ/tPZL
tPHZ/tPZH
Open
6 V
GND
TEST S1
NOTES: A. CL includes probe and jig capacitance.
B. W aveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
W aveform 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 ≤10 MHz, ZO = 50 Ω, tr ≤2.5 ns, tf ≤2.5 ns.
D. The outputs are measured one at a time with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd.
Figure 3. Load Circuit and Voltage Waveforms
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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 1998, Texas Instruments Incorporated
