®
74ACT244
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (NON INVERTED)
s
s
s
s
s
s
s
s
s
HIGH SPEED: t
PD
= 4.5 ns (TYP.) at V
CC
= 5V
LOW POWER DISSIPATION:
I
CC
= 8
µA
(MAX.) at T
A
= 25
o
C
COMPATIBLE WITH TTL OUTPUTS
V
IH
= 2V (MIN), V
IL
= 0.8V (MAX)
50Ω TRANSMISSION LINE DRIVING
CAPABILITY
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24 mA (MIN)
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 4.5V to 5.5V
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 244
IMPROVED LATCH-UP IMMUNITY
M
(Micro Package)
B
(Plastic Package)
ORDER CODES :
74ACT244B
74ACT244M
74ACT244T
T
(TSSOP Package)
DESCRIPTION
The ACT244 is an advanced CMOS OCTAL BUS
BUFFER (3-STATE) fabricated with sub-micron
silicon gate and double-layer metal wiring C
2
MOS
technology. It is ideal for low power applications
mantaining high speed operation similar to
equivalent Bipolar Schottky TTL.
G control output governs four BUS BUFFERs.
This device is desibned to be used with 3 state
memory address drivers, etc.
The device is designed to interface directly High
Speed CMOS systems with TTL, NMOS and
CMOS output voltage levels.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
February 1999
1/9
74ACT244
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
PIN No
1
2, 4,6, 8
9, 7,5, 3
11, 13, 15, 17
18, 16, 14, 12
19
10
20
SYMBOL
1G
1A1 to 1A4
2Y1 to 2Y4
2A1 to 2A4
1Y1 to 1Y4
2G
GND
V
CC
NAME AND FUNCT ION
Output Enable Input
Data Inputs
Data Outputs
Data Inputs
Data Outputs
Output Enabel Input
Ground (0V)
Positive Supply Voltage
TRUTH TABLE
INPUT
G
L
L
H
X:”H” or ”L”
Z: High impedance
OUTPUT
An
L
H
X
Yn
L
H
Z
ABSOLUTE MAXIMUM RATINGS
Symbol
V
CC
V
I
V
O
I
IK
I
OK
I
O
I
CC
orI
GND
T
stg
T
L
Supply Voltage
DC Input Voltage
DC Output Voltage
DC Input Diode Current
DC Output Diode Current
DC Output Current
DC V
CC
or Ground Current
Storage Temperature
Lead Temperature (10 sec)
Parameter
Value
-0.5 to +7
-0.5 to V
CC
+ 0.5
-0.5 to V
CC
+ 0.5
±
20
±
20
±
50
±
400
-65 to +150
300
Unit
V
V
V
mA
mA
mA
mA
o
o
C
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
I
V
O
T
op
dt/dv
Supply Voltage
Input Voltage
Output Voltage
Operating Temperature:
Input Rise and Fall Time V
CC
= 4.5 to 5.5V (note 1)
Parameter
Value
4.5 to 5.5
0 to V
CC
0 to V
CC
-40 to +85
8
Unit
V
V
V
o
C
ns/V
1) V
IN
from 0.8 V to 2.0 V
2/9
74ACT244
AC ELECTRICAL CHARACTERISTICS
(C
L
= 50 pF, R
L
= 500
Ω,
Input t
r
= t
f
=3 ns)
Symb ol
Parameter
V
CC
(V)
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
Propagation Delay Time
Output Enable Time
Output Disable Time
5.0
(*)
T est Con ditio n
Valu e
T
A
= 25 C
-40 to 85
o
C
o
Un it
Min.
1.5
1.5
1.5
T yp.
4.5
5.5
6.5
Max.
9.0
9.0
10.0
Min.
1.5
1.5
1.5
Max.
10.0
10.0
11.0
ns
ns
ns
5.0
(*)
5.0
(*)
(*) Voltage range is 5V
±
0.5V
CAPACITIVE CHARACTERISTICS
Symb ol
Parameter
V
CC
(V)
C
IN
C
i/o
C
PD
Input Capacitance
I/O Capacitance
Power Dissipation
Capacitance (note 1)
5.0
5.0
5.0
Test Co nditions
o
Valu e
-40 to 85 C
T
A
= 25 C
Min. T yp. Max. Min. Max.
4
8
24
o
Un it
pF
pF
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 operating current can be obtained by the following equation. I
CC
(opr) = C
PD
•
V
CC
•
f
IN
+ I
CC
/n (per circuit)
TEST CIRCUIT
T EST
t
PLH
, t
PHL
t
PZL
, t
PLZ
t
PZH
, t
PHZ
C
L
= 50 pF or equivalent (includes jigand probe capacitance)
R
L
= R
1
= 500Ω orequivalent
R
T
= Z
OUT
of pulse generator (typically 50Ω)
SW IT CH
Open
2V
CC
Open
4/9
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