HD74LV126A
Quad. Bus Buffer Gates with 3-state Outputs
ADE-205-259 (Z)
1st Edition
March 1999
Description
The HD74LV126A features independent line drivers with three state outputs. Each output is disabled when
the associated output enable (OE) input is low. To ensure the high impedance state during power up or
power down, OE should be connected to GND through a pull-down resistor; the minimum value of the
resistor is determined by the current souring capability of the driver. Low-voltage and high-speed operation
is suitable for the battery-powered products (e.g., notebook computers), and the low-power consumption
extends the battery life.
Features
V
CC
= 2.0 V to 5.5 V operation
All inputs V
IH
(Max.) = 5.5 V (@V
CC
= 0 V to 5.5 V)
All outputs V
O
(Max.) = 5.5 V (@V
CC
= 0 V)
Typical V
OL
ground bounce < 0.8 V (@V
CC
= 3.3 V, Ta = 25
C)
Typical V
OH
undershoot > 2.3 V (@V
CC
= 3.3 V, Ta = 25
C)
Output current
8 mA (@V
CC
= 3.0 V to 3.6 V),
16 mA (@V
CC
= 4.5 V to 5.5 V)
Function Table
Inputs
OE
A
Output Y
H
H
H
H
L
L
L
X
Z
Note:
H: High level
L: Low level
X: Immaterial
Z: High impedance
HD74LV126A
3
Absolute Maximum Ratings
Item
Symbol
Ratings
Unit
Conditions
Supply voltage range
V
CC
0.5 to 7.0
V
Input voltage range*
1
V
I
0.5 to 7.0
V
Output voltage range*
1, 2
V
O
0.5 to V
CC
+ 0.5
V
Output: H or L
0.5 to 7.0
V
CC
: OFF or Output: Z
Input clamp current
I
IK
20
mA
V
I
< 0
Output clamp current
I
OK
50
mA
V
O
< 0 or V
O
> V
CC
Continuous output current
I
O
35
mA
V
O
= 0 to V
CC
Continuous current through
V
CC
or GND
I
CC
or I
GND
70
mA
Maximum power dissipation
at Ta = 25
C (in still air)*
3
P
T
785
mW
SOP
500
TSSOP
Storage temperature
Tstg
65 to 150
C
Notes: The absolute maximum ratings are values which must not individually be exceeded, and furthermore,
no two of which may be realized at the same time.
1. The input and output voltage ratings may be exceeded if the input and output clamp-current
ratings are observed.
2. This value is limited to 5.5 V maximum.
3. The maximum package power dissipation was calculated using a junction temperature of 150
C.
HD74LV126A
4
Recommended Operating Conditions
Item
Symbol
Min
Max
Unit
Conditions
Supply voltage range
V
CC
2.0
5.5
V
Input voltage range
V
I
0
5.5
V
Output voltage range
V
O
0
V
CC
V
H or L
0
5.5
High impedance state
Output current
I
OH
--
50
A
V
CC
= 2.0 V
--
2
mA
V
CC
= 2.3 to 2.7 V
--
8
V
CC
= 3.0 to 3.6 V
--
16
V
CC
= 4.5 to 5.5 V
I
OL
--
50
A
V
CC
= 2.0 V
--
2
mA
V
CC
= 2.3 to 2.7 V
--
8
V
CC
= 3.0 to 3.6 V
--
16
V
CC
= 4.5 to 5.5 V
Input transition rise or fall rate
t /
v
0
200
ns/V
V
CC
= 2.3 to 2.7 V
0
100
V
CC
= 3.0 to 3.6 V
0
20
V
CC
= 4.5 to 5.5 V
Operating free-air temperature
Ta
40
85
C
Note:
Unused or floating inputs must be held high or low.
Logic Diagram
1Y
2Y
3Y
4Y
4A
4OE
3A
3OE
1A
1OE
2A
2OE
3
1
2
4
5
10
9
13
12
6
8
11
HD74LV126A
5
DC Electrical Characteristics
Ta = 40 to 85
C
Item
Symbol
V
CC
(V)*
Min
Typ
Max
Unit
Test Conditions
Input voltage
V
IH
2.0
1.5
--
--
V
2.3 to 2.7
V
CC
0.7
--
--
3.0 to 3.6
V
CC
0.7
--
--
4.5 to 5.5
V
CC
0.7
--
--
V
IL
2.0
--
--
0.5
2.3 to 2.7
--
--
V
CC
0.3
3.0 to 3.6
--
--
V
CC
0.3
4.5 to 5.5
--
--
V
CC
0.3
Output voltage
V
OH
Min to
Max
V
CC
0.1
--
--
V
I
OH
= 50
A
2.3
2.0
--
--
I
OH
= 2 mA
3.0
2.48
--
--
I
OH
= 8 mA
4.5
3.8
--
--
I
OH
= 16 mA
V
OL
Min to
Max
--
--
0.1
I
OL
= 50
A
2.3
--
--
0.4
I
OL
= 2 mA
3.0
--
--
0.44
I
OL
= 8 mA
4.5
--
--
0.55
I
OL
= 16 mA
Input current
I
IN
0 to 5.5
--
--
1
A
V
I
= 5.5 V or GND
Off-state
output current
I
OZ
5.5
--
--
5
A
V
O
= V
CC
or GND
Quiescent
supply current
I
CC
5.5
--
--
20
A
V
I
= V
CC
or GND, I
O
= 0
Output leakage
current
I
OFF
0
--
--
5
A
V
I
or V
O
= 0 V to 5.5 V
Input
capacitance
C
IN
3.3
--
3
--
pF
V
I
= V
CC
or GND
Note:
For conditions shown as Min or Max, use the appropriate values under recommended operating
conditions.
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