74VHCT125A
QUAD BUS BUFFERS (3-STATE)
PRELIMINARY DATA
August 1999
PIN CONNECTION AND IEC LOGIC SYMBOLS
s
HIGH SPEED: t
PD
= 3.8 ns (TYP.) at V
CC
= 5V
s
LOW POWER DISSIPATION:
I
CC
= 4
A (MAX.) at T
A
= 25
o
C
s
COMPATIBLE WITH TTL OUTPUTS:
V
IH
= 2V (MIN), V
IL
= 0.8V (MAX)
s
POWER DOWN PROTECTION ON INPUTS &
OUTPUTS
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 8 mA (MIN)
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 4.5V to 5.5V
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 125
s
IMPROVED LATCH-UP IMMUNITY
s
LOW NOISE: V
OLP
= 0.8V (Max.)
DESCRIPTION
The 74VHCT125A is an advanced high-speed
CMOS QUAD BUS BUFFERS fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology.
This device requires the 3-STATE control input G
to be set high to place the output into the high
impedance state.
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
device can be used to interface 5V to 3V.
All inputs
and
outputs are
equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
ORDER CODES :
74VHCT125AM
74VHCT125AT
M
(Micro Package)
T
(TSSOP Package)
1/8
TRUTH TABLE
A
G
Y
X
H
Z
L
L
L
H
L
H
X:"H" or "L"
Z:High Impadance
PIN DESCRIPTION
PI N No
SYMBOL
NAME AND FUNCT ION
1, 4, 10, 13
1G to 4G
Output Enable Inputs
2, 5, 9, 12
1A to 4A
Data Inputs
3, 6, 8, 11
1Y to 4Y
Data Outputs
7
GND
Ground (0V)
14
V
CC
Positive Supply Voltage
INPUT EQUIVALENT CIRCUIT
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Valu e
Uni t
V
CC
Supply Voltage
4.5 to 5.5
V
V
I
Input Voltage
0 to 5.5
V
V
O
Output Voltage (see note 1)
0 to 5.5
V
V
O
Output Voltage (see note 2)
0 to V
CC
V
T
op
Operating Temperature
-40 to +85
o
C
dt/dv
Input Rise and Fall Time (see note 3) (V
CC
= 5.0
0.5V)
0 to 20
ns/V
1) Output in OFF State
2) High or Low State
3)V
IN
from0.8V to 2 V
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Val ue
Unit
V
CC
Supply Voltage
-0.5 to +7.0
V
V
I
DC Input Voltage
-0.5 to +7.0
V
V
O
DC Output Voltage (see note 1)
-0.5 to +7.0
V
V
O
DC Output Voltage (see note 2)
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
- 20
mA
I
OK
DC Output Diode Current
20
mA
I
O
DC Output Current
25
mA
I
CC
or I
GND
DC V
CC
or Ground Current
50
mA
T
stg
Storage Temperature
-65 to +150
o
C
T
L
Lead Temperature (10 sec)
300
o
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
1) Output in OFF State
2) High or Low State
74VHCT125A
2/8
AC ELECTRICAL CHARACTERISTICS (Input t
r
= t
f
=3 ns)
Symb ol
Parameter
Test Co nditi on
Val ue
Un it
V
CC
(V)
C
L
(pF )
T
A
= 25
o
C
-40 to 85
o
C
Min.
Typ .
Max.
Min .
Max.
t
PLH
t
PHL
Propagation Delay
Time
5.0
(*)
15
R
L
= 1K
3.8
5.5
1.0
6.5
ns
5.0
(*)
50
R
L
= 1K
5.3
7.5
1.0
8.5
t
PLZ
t
PHZ
Output Disable Time
5.0
(*)
15
R
L
= 1K
3.6
5.1
1.0
6.0
ns
5.0
(*)
50
R
L
= 1K
5.1
7.1
1.0
8.0
t
PZL
t
PZH
Output Enable Time
5.0
(*)
50
R
L
= 1K
6.1
8.8
1.0
10.0
ns
(*) Voltage range is 5.0V
0.5V
DC SPECIFICATIONS
Symb ol
Parameter
T est Cond ition s
Val ue
Un it
V
CC
(V)
T
A
= 25
o
C
-40 to 85
o
C
Min.
Typ .
Max.
Min .
Max.
V
IH
High Level Input
Voltage
4.5 to 5.5
2
2
V
V
IL
Low Level Input
Voltage
4.5 to 5.5
0.8
0.8
V
V
OH
High Level Output
Voltage
4.5
I
O
=-50
A
4.4
4.5
4.4
V
4.5
I
O
=-8 mA
3.94
3.8
V
OL
Low Level Output
Voltage
4.5
I
O
=50
A
0.0
0.1
0.1
V
4.5
I
O
=8 mA
0.36
0.44
I
OZ
High Impedance
Output Leakage
Current
4.5 to 5.5
V
I
= V
IH
or V
IL
V
O
= 0V to 5.5V
0.25
2.5
A
I
I
Input Leakage Current
0 to 5.5
V
I
= 5.5V or GND
0.1
1.0
A
I
CC
Quiescent Supply
Current
5.5
V
I
= V
CC
or GND
4
40
A
I
CC
Additional Worst Case
Supply Current
5.5
One Input at 3.4V,
other input at V
CC
or
GND
1.35
1.5
mA
I
OPD
Output Leakage
Current
0
V
OUT
= 5.5V
0.5
5.0
A
74VHCT125A
3/8
CAPACITIVE CHARACTERISTICS
Symb ol
Parameter
Test Co nditi ons
Valu e
Un it
T
A
= 25
o
C
-40 to 85
o
C
Min.
T yp.
Max.
Mi n.
Max.
C
IN
Input Capacitance
4
10
10
pF
C
OUT
Output Capacitance
10
pF
C
PD
Power Dissipation
Capacitance (note 1)
14
pF
1) C
PD
isdefined as the value of the IC'sinternal equivalent capacitance which is calculated fromthe operating current consumption without load. (Referto
Test Circuit).Average operting current can be obtained by the following equation. I
CC
(opr) = C
PD
V
CC
f
IN
+ I
CC
/4(per circuit)
TEST CIRCUIT
T EST
SW IT CH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
CC
t
PZH
, t
PHZ
GND
C
L
= 15/50 pF or equivalent (includes jig and probe capacitance)
R
L
= R
1
= 1K
orequivalent
R
T
= Z
OUT
of pulse generator (typically 50
)
DYNAMIC SWITCHING CHARACTERISTICS
Symb ol
Parameter
T est Cond ition s
Val ue
Un it
V
CC
(V)
T
A
= 25
o
C
-40 to 85
o
C
Min.
Typ .
Max.
Min .
Max.
V
OLP
Dynamic Low Voltage
Quiet Output (note 1, 2)
5.0
C
L
= 50 pF
0.3
0.8
V
V
OLV
-0.8
-0.3
V
IHD
Dynamic High Voltage
Input (note 1, 3)
5.0
2
V
IL D
Dynamic Low Voltage
Input (note 1, 3)
5.0
0.8
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n -1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to3.0V. Inputs under test switching: 3.0V to threshold (V
ILD
), 0V to threshold (V
IHD
), f=1MHz.
74VHCT125A
4/8
WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle)
WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
74VHCT125A
5/8
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