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SN54LVT244A, SN74LVT244A
3.3-V ABT OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS354 – FEBRUARY 1994
•
•
•
•
•
•
•
•
State-of-the-Art Advanced BiCMOS
Technology (ABT) Design for 3.3-V
Operation and Low-Static Power
Dissipation
Supports Mixed-Mode Signal Operation
(5-V Input and Output Voltages With
3.3-V V
CC
)
Supports Unregulated Battery Operation
Down to 2.7 V
Typical V
OLP
(Output Ground Bounce)
< 0.8 V at V
CC
= 3.3 V, T
A
= 25°C
Latch-Up Performance Exceeds 500 mA
Per JEDEC Standard JESD-17
Bus-Hold Data Inputs Eliminate the Need
for External Pullup Resistors
Supports Live Insertion
Package Options Include Plastic
Small-Outline (DW), Shrink Small-Outline
(DB), and Thin Shrink Small-Outline (PW)
Packages, Ceramic Chip Carriers (FK), and
Ceramic DIPs (J)
SN54LVT244A . . . J PACKAGE
SN74LVT244A . . . DB, DW, OR PW PACKAGE
(TOP VIEW)
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
2OE
1Y1
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1
SN54LVT244A . . . FK PACKAGE
(TOP VIEW)
description
These octal buffers and line drivers are designed
specifically for low-voltage (3.3-V) V
CC
operation,
but with the capability to provide a TTL interface to
a 5-V system environment.
1A2
2Y3
1A3
2Y2
1A4
4
5
6
7
8
3 2 1 20 19
18
17
16
15
14
9 10 11 12 13
2Y4
1A1
1OE
V
CC
2OE
1Y1
2A4
1Y2
2A3
1Y3
The
′LVT244A
is organized as two 4-bit line drivers with separate output-enable (OE) inputs. When OE is low,
the device passes data from the A inputs to the Y outputs. When OE is high, the outputs are in the
high-impedance state.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level.
To ensure the high-impedance state during power up or power down, OE should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN74LVT244A is available in TI’s shrink small-outline package (DB), which provides the same I/O pin count
and functionality of standard small-outline packages in less than half the printed-circuit-board area.
The SN54LVT244A is characterized for operation over the full military temperature range of – 55°C to 125°C.
The SN74LVT244A is characterized for operation from – 40°C to 85°C.
FUNCTION TABLE
(each buffer)
INPUTS
OE
L
L
H
A
H
L
X
OUTPUT
Y
H
L
Z
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information 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
Copyright
©
1994, Texas Instruments Incorporated
2Y1
GND
2A1
1Y4
2A2
•
DALLAS, TEXAS 75265
LVT244–5
2–1
SN54LVT244A, SN74LVT244A
3.3-V ABT OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS354 – FEBRUARY 1994
logic symbol
†
1OE
1
EN
18
16
14
12
logic diagram (positive logic)
1OE
1
1A1
1A2
1A3
1A4
2
4
6
8
1Y1
1Y2
1Y3
1Y4
1A1
2
18
1Y1
1A2
4
16
1Y2
1A3
2OE
19
EN
1A4
2A1
2A2
2A3
2A4
11
13
15
17
9
7
5
3
2Y1
2Y2
2Y3
2Y4
2OE
6
14
1Y3
12
8
1Y4
19
11
† This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
2A1
13
9
2Y1
7
2Y2
5
2Y3
3
2A2
15
2A3
17
2A4
2Y4
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
‡
Supply voltage range, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 4.6 V
Input voltage range, V
I
(see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V
Voltage range applied to any output in the high state or power-off state, V
O
(see Note 1) . . . . – 0.5 V to 7 V
Current into any output in the low state, I
O
: SN54LVT244A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 mA
SN74LVT244A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 mA
Current into any output in the high state, I
O
(see Note 2): SN54LVT244A . . . . . . . . . . . . . . . . . . . . . . . . 48 mA
SN74LVT244A . . . . . . . . . . . . . . . . . . . . . . . . 64 mA
Input clamp current, I
IK
(V
I
< 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 50 mA
Output clamp current, I
OK
(V
O
< 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 50 mA
Maximum power dissipation at T
A
= 55°C (in still air) (see Note 3): DB package . . . . . . . . . . . . . . . . . . . . 0.6 W
DW package . . . . . . . . . . . . . . . . . . . 1.6 W
PW package . . . . . . . . . . . . . . . . . . . 0.7 W
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 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 negative-voltage ratings may be exceeded if the input and output clamp-current ratings are observed.
2. This current will only flow when the output is in the high state and VO > VCC.
3. The maximum package power dissipation is calculated using a junction temperature of 150°C and a board trace length of 750 mils.
For more information, refer to the
Package Thermal Considerations
application note.
2–2
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
LVT244–5
SN54LVT244A, SN74LVT244A
3.3-V ABT OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS354 – FEBRUARY 1994
recommended operating conditions (see Note 4)
SN54LVT244A
MIN
VCC
VIH
VIL
VI
IOH
IOL
∆t
/∆v
Supply voltage
High-level input voltage
Low-level input voltage
Input voltage
High-level output current
Low-level output current
Input transition rise or fall rate
Outputs enabled
– 55
2.7
2
0.8
5.5
– 24
48
10
125
– 40
MAX
3.6
SN74LVT244A
MIN
2.7
2
0.8
5.5
– 32
64
10
85
MAX
3.6
UNIT
V
V
V
V
mA
mA
ns / V
°C
TA
Operating free-air temperature
NOTE 4: Unused or floating control inputs must be held high or low.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
LVT244–5
2–3
SN54LVT244A, SN74LVT244A
3.3-V ABT OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS354 – FEBRUARY 1994
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
TEST CONDITIONS
VCC = 2.7 V,
VCC = MIN to MAX‡,
VCC = 2.7 V,
VCC = 3 V,
VCC = 3 V,
VCC = 2.7 V,
VCC = 2.7 V,
VCC = 3 V,
VCC = 3 V,
VCC = 3 V,
VCC = 3 V,
VCC = 0 or MAX‡,
II
VCC = 3.6 V,
VCC = 3.6 V,
VCC = 3.6 V,
VCC = 0,
VCC = 3 V
VCC = 3.6 V,
VCC = 3.6 V,
VCC = 3.6 V,
VI = VCC or GND
II = –18 mA
IOH = –100
µA
IOH = – 8 mA
IOH = – 24 mA
IOH = – 32 mA
IOL = 100
µA
IOL = 24 mA
IOL = 16 mA
IOL = 32 mA
IOL = 48 mA
IOL = 64 mA
VI = 5.5 V
VI = VCC or GND
VI = VCC
VI = 0
VI or VO = 0 to 4.5 V
VI = 0.8 V
VI = 2 V
VO = 3 V
VO = 0.5 V
Outputs high
ICC
IO = 0,
Outputs low
Outputs
disabled
0.12
8.6
0.12
Control pins
Data pins
SN54LVT244A
MIN TYP†
MAX
–1.2
VCC – 0.2
2.4
2
2
0.2
0.5
0.4
0.5
0.55
0.55
10
±1
1
–5
75
–75
5
–5
0.5
14
0.5
0.3
4
8
4
8
0.12
8.6
0.12
75
–75
5
–5
0.19
12
0.19
0.2
mA
pF
pF
mA
10
±1
1
–5
±
100
A inputs
µA
µA
µA
µA
µA
0.2
0.5
0.4
0.5
V
VCC – 0.2
2.4
SN74LVT244A
MIN TYP†
MAX
–1.2
UNIT
V
VOH
V
VOL
Ioff
II(hold)
I(h ld)
IOZH
IOZL
∆I
CC§
Ci
Co
VCC = 3 V to 3.6 V,
One input at VCC – 0.6 V,
Other inputs at VCC or GND
VI = 3 V or 0
VO = 3 V or 0
† All typical values are at VCC = 3.3 V, TA = 25°C.
‡ For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
§ This is the increase in supply current for each input that is at the specified TTL voltage level rather than VCC or GND.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
2–4
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
LVT244–5
嵌入式系统
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