74AC125
QUAD BUS BUFFERS (3-STATE)
PRELIMINARY DATA
May 1997
PIN CONNECTION AND IEC LOGIC SYMBOLS
s
HIGH SPEED: t
PD
= 5 ns (TYP.) at V
CC
= 5V
s
LOW POWER DISSIPATION:
I
CC
= 8
A (MAX.) at T
A
= 25
o
C
s
HIGH NOISE IMMUNITY:
V
NIH
= V
NIL
= 28% V
CC
(MIN.)
s
50
TRANSMISSION LINE DRIVING
CAPABILITY
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24 mA (MIN)
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 6V
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 125
s
IMPROVED LATCH-UP IMMUNITY
DESCRIPTION
The AC125 is an high-speed CMOS QUAD BUS
BUFFERS fabricated with sub-micron silicon gate
and
double-layer
metal
wiring
C
2
MOS
technology. It is ideal for low power applications
maintaining high speed operation similar to
equivalent Bipolar Schottky TTL.
These devices require the same 3-STATE control
input G to be taken high to make the output go in
to the high impedance state.
All
inputs and
outputs
are
equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
ORDER CODES :
74AC125B
74AC125M
M
(Micro Package)
B
(Plastic Package)
1/8
INPUT AND OUTPUT EQUIVALENT CIRCUIT
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Val ue
Uni t
V
CC
Supply Voltage
-0.5 to +7
V
V
I
DC Input Voltage
-0.5 to V
CC
+ 0.5
V
V
O
DC Output Voltage
-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
50
mA
I
CC
or I
GND
DC V
CC
or Ground Current
200
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.
TRUTH TABLE
A
G
Y
X
H
Z
L
L
L
H
L
H
PIN DESCRIPTION
PI N No
SYMBOL
NAME AND F UNCTIO N
1, 4, 10, 13
G1 to G4
Output Enable Inputs
2, 5, 9, 12
A1 to A4
Data Inputs
3, 6, 8, 11
Y1 to Y4
Data Outputs
7
GND
Ground (0V)
14
V
CC
Positive Supply Voltage
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Un it
V
CC
Supply Voltage
2 to 6
V
V
I
Input Voltage
0 to V
CC
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature:
-40 to +85
o
C
dt/dv
Input Rise and Fall Time V
CC
= 3.0, 4.5 or 5.5 V(note 1)
8
ns/V
1) V
IN
from 30% to 70% of V
CC
74AC125
2/8
DC SPECIFICATIONS
Symbol
Parameter
Test Con dition s
Value
Unit
V
CC
(V)
T
A
= 25
o
C
-40 to 85
o
C
Mi n.
Typ.
Max.
Min .
Max.
V
IH
High Level Input Voltage
3.0
V
O
= 0.1 V or
V
CC
- 0.1 V
2.1
1.5
2.1
V
4.5
3.15
2.25
3.15
5.5
3.85
2.75
3.85
V
IL
Low Level Input Voltage
3.0
V
O
= 0.1 V or
V
CC
- 0.1 V
1.5
0.9
0.9
V
4.5
2.25
1.35
1.35
5.5
2.75
1.65
1.65
V
OH
High Level Output
Voltage
3.0
V
I
(*)
=
V
IH
or
V
IL
I
O
=-50
A
2.9
2.99
2.9
V
4.5
I
O
=-50
A
4.4
4.49
4.4
5.5
I
O
=-50
A
5.4
5.49
5.4
3.0
I
O
=-12 mA
2.56
2.46
4.5
I
O
=-24 mA
3.86
3.76
5.5
I
O
=-24 mA
4.86
4.76
V
OL
Low Level Output
Voltage
3.0
V
I
(*)
=
V
IH
or
V
IL
I
O
=50
A
0.002
0.1
0.1
V
4.5
I
O
=50
A
0.001
0.1
0.1
5.5
I
O
=50
A
0.001
0.1
0.1
3.0
I
O
=12 mA
0.36
0.44
4.5
I
O
=24 mA
0.36
0.44
5.5
I
O
=24 mA
0.36
0.44
I
I
Input Leakage Current
5.5
V
I
= V
CC
or GND
0.1
1
A
I
OZ
3 State Output Leakage
Current
5.5
V
I
= V
IH
or V
IL
V
O
= V
CC
or GND
0.5
5
A
I
CC
Quiescent Supply
Current
5.5
V
I
= V
CC
or GND
8
80
A
I
OLD
Dynamic Output Current
(note 1, 2)
5.5
V
OLD
= 1.65 V max
75
mA
I
OHD
V
OHD
= 3.85 V min
-75
mA
1) Maximum test duration 2ms, one output loaded at time
2) Incident wave switching is guaranteed on transmission lines with impedances as low as 50
.
(*) All outputs loaded.
74AC125
3/8
TEST CIRCUIT
TEST
SWI TCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
2V
CC
t
PZH
, t
PHZ
Open
C
L
= 50 pF or equivalent (includes jig and probe capacitance)
R
L
= R
1
= 500
or equivalent
R
T
= Z
OUT
of pulse generator (typically 50
)
CAPACITIVE CHARACTERISTICS
Symbol
Parameter
Test Con dition s
Value
Unit
V
CC
(V)
T
A
= 25
o
C
-40 to 85
o
C
Mi n.
Typ.
Max.
Min .
Max.
C
IN
Input Capacitance
5.0
4
pF
C
OUT
Output Capacitance
5.0
8
pF
C
PD
Power Dissipation
Capacitance (note 1)
5.0
TBD
pF
1) C
PD
is defined as the value of the IC's internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to
Test Circuit). Average operating current can be obtained by the following equation. I
CC
(opr) = C
PD
V
CC
f
IN
+ I
CC
/n (per circuit)
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, R
L
= 500
, Input t
r
= t
f
=3 ns)
Symbol
Parameter
T est Cond iti on
Value
Unit
V
CC
(V)
T
A
= 25
o
C
-40 to 85
o
C
Mi n.
Typ.
Max.
Min .
Max.
t
PLH
t
PHL
Propagation Delay Time
3.3
(*)
1.0
6.5
9.0
1.0
10.0
ns
5.0
(**)
1.0
5.0
7.0
1.0
7.5
t
PZL
t
PZH
Output Enable Time
3.3
(*)
1.0
6.0
10.0
1.0
11.0
ns
5.0
(**)
1.0
5.0
7.0
1.0
8.0
t
PLZ
t
PHZ
Output Disable Time
3.3
(*)
1.0
7.5
10.0
1.0
11.0
ns
5.0
(**)
1.0
6.5
9.0
1.0
9.5
(*) Voltage range is 3.3V
0.3V
(**) Voltage range is 5V
0.5V
74AC125
4/8
WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle)
WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
74AC125
5/8
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