74LCX244
LOW VOLTAGE CMOS OCTAL BUS BUFFER (3-STATE)
WITH 5V TOLERANT INPUTS AND OUTPUTS
s
s
s
s
s
s
s
s
s
s
5V TOLERANT INPUTS AND OUTPUTS
HIGH SPEED :
t
PD
= 6.5 ns (MAX.) at V
CC
= 3V
POWER DOWN PROTECTION ON INPUTS
AND OUTPUTS
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24mA (MIN) at V
CC
= 3V
PCI BUS LEVELS GUARANTEED AT 24 mA
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2.0V to 3.6V (1.5V Data
Retention)
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 244
LATCH-UP PERFORMANCE EXCEEDS
500mA (JESD 17)
ESD PERFORMANCE:
HBM > 2000V (MIL STD 883 method 3015);
MM > 200V
SOP
TSSOP
ORDER CODES
PACKAGE
SOP
TSSOP
TUBE
74LCX244M
T&R
74LCX244MTR
74LCX244TTR
DESCRIPTION
The 74LCX244 is a low voltage CMOS OCTAL
BUS BUFFER (NON-INVERTED) fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology. It is ideal for low power
and high speed 3.3V applications; it can be
interfaced to 5V signal environment for both inputs
and outputs.
It has same speed performance at 3.3V than 5V
AC/ACT family, combined with a lower power
consumption.
This device is designed to be used with 3 state
memory address drivers, etc.
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
March 2002
1/9
74LCX244
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 FUNCTION
Output Enable Input
Data Inputs
Data Outputs
Data Inputs
Data Outputs
Output Enable Input
Ground (0V)
Positive Supply Voltage
TRUTH TABLE
INPUT
G
L
L
H
X : Don’t Care
Z : High Impedance
OUTPUT
An
L
H
X
Yn
L
H
Z
ABSOLUTE MAXIMUM RATINGS
Symbol
V
CC
V
I
V
O
V
O
I
IK
I
OK
I
O
I
CC
I
GND
T
stg
T
L
Supply Voltage
DC Input Voltage
DC Output Voltage (OFF State)
DC Output Voltage (High or Low State) (note 1)
DC Input Diode Current
DC Output Diode Current (note 2)
DC Output Current
DC Supply Current per Supply Pin
DC Ground Current per Supply Pin
Storage Temperature
Lead Temperature (10 sec)
Parameter
Value
-0.5 to +7.0
-0.5 to +7.0
-0.5 to +7.0
-0.5 to V
CC
+ 0.5
- 50
- 50
±
50
±
100
±
100
-65 to +150
300
Unit
V
V
V
V
mA
mA
mA
mA
mA
°C
°C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) I
O
absolute maximum rating must be observed
2) V
O
< GND
2/9
74LCX244
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
I
V
O
V
O
I
OH
, I
OL
I
OH
, I
OL
T
op
dt/dv
Supply Voltage (note 1)
Input Voltage
Output Voltage (OFF State)
Output Voltage (High or Low State)
High or Low Level Output Current (V
CC
= 3.0 to 3.6V)
High or Low Level Output Current (V
CC
= 2.7V)
Operating Temperature
Input Rise and Fall Time (note 2)
Parameter
Value
2.0 to 3.6
0 to 5.5
0 to 5.5
0 to V
CC
±
24
±
12
-55 to 125
0 to 10
Unit
V
V
V
V
mA
mA
°C
ns/V
1) Truth Table guaranteed: 1.5V to 3.6V
2) V
IN
from 0.8V to 2V at V
CC
= 3.0V
DC SPECIFICATIONS
Test Condition
Symbol
Parameter
V
CC
(V)
-40 to 85 °C
Min.
2.0
2.7 to 3.6
0.8
2.7 to 3.6
2.7
3.0
V
OL
Low Level Output
Voltage
2.7 to 3.6
2.7
3.0
I
I
I
off
I
OZ
Input Leakage
Current
Power Off Leakage
Current
High Impedance
Output Leakage
Current
Quiescent Supply
Current
I
CC
incr. per Input
2.7 to 3.6
0
2.7 to 3.6
I
O
=-100
µA
I
O
=-12 mA
I
O
=-18 mA
I
O
=-24 mA
I
O
=100
µA
I
O
=12 mA
I
O
=16 mA
I
O
=24 mA
V
I
= 0 to 5.5V
V
I
or V
O
= 5.5V
V
I
= V
IH
or V
IL
V
O
= 0 to V
CC
V
I
= V
CC
or GND
V
I
or V
O
= 3.6 to 5.5V
V
IH
= V
CC
- 0.6V
V
CC
-0.2
2.2
2.4
2.2
0.2
0.4
0.4
0.55
±
5
10
V
CC
-0.2
2.2
2.4
2.2
0.2
0.4
0.4
0.55
±
5
10
µA
µA
V
V
0.8
V
Max.
Value
-55 to 125 °C
Min.
2.0
Max.
V
Unit
V
IH
V
IL
V
OH
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
±
5
10
±
10
500
±
5
10
±
10
500
µA
µA
µA
I
CC
∆I
CC
2.7 to 3.6
2.7 to 3.6
3/9
74LCX244
DYNAMIC SWITCHING CHARACTERISTICS
Test Condition
Symbol
Parameter
V
CC
(V)
3.3
C
L
= 50pF
V
IL
= 0V, V
IH
= 3.3V
Value
T
A
= 25 °C
Min.
Typ.
0.8
-0.8
Max.
V
Unit
V
OLP
V
OLV
Dynamic Low Level Quiet
Output (note 1)
1) Number of outputs defined as "n". Measured with "n-1" outputs switching from HIGH to LOW or LOW to HIGH. The remaining output is
measured in the LOW state.
AC ELECTRICAL CHARACTERISTICS
Test Condition
Symbol
Parameter
V
CC
(V)
2.7
3.0 to 3.6
2.7
3.0 to 3.6
2.7
3.0 to 3.6
3.0 to 3.6
C
L
(pF)
50
50
50
50
R
L
(Ω)
500
500
500
500
t
s
=
t
r
(ns)
2.5
2.5
2.5
2.5
-40 to 85 °C
Min.
1.5
1.5
1.5
1.5
1.5
1.5
Max.
7.5
6.5
9.0
8.0
8.0
7.0
1.0
Value
-55 to 125 °C
Min.
1.5
1.5
1.5
1.5
1.5
1.5
Max.
8.2
7.1
10.5
9.2
9.2
7.7
1.0
ns
ns
ns
ns
Unit
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
t
OSLH
t
OSHL
Propagation Delay
Time
Output Enable Time
Output Disable Time
Output To Output
Skew Time (note1,
2)
1) Skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switch-
ing in the same direction, either HIGH or LOW (t
OSLH
= | t
PLHm
- t
PLHn
|, t
OSHL
= | t
PHLm
- t
PHLn
|)
2) Parameter guaranteed by design
CAPACITIVE CHARACTERISTICS
Test Condition
Symbol
Parameter
V
CC
(V)
3.3
3.3
3.3
V
IN
= 0 to V
CC
V
IN
= 0 to V
CC
f
IN
= 10MHz
V
IN
= 0 or V
CC
Value
T
A
= 25 °C
Min.
Typ.
6
10
34
Max.
pF
pF
pF
Unit
C
IN
C
OUT
C
PD
Input Capacitance
Output Capacitance
Power Dissipation Capacitance
(note 1)
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
x V
CC
x f
IN
+ I
CC
/8 (per circuit)
4/9
74LCX244
TEST CIRCUIT
TEST
t
PLH
, t
PHL
t
PZL
, t
PLZ
t
PZH
, t
PHZ
C
L
= 50 pF or equivalent (includes jig and probe capacitance)
R
L
= R1 = 500Ω or equivalent
R
T
= Z
OUT
of pulse generator (typically 50Ω)
SWITCH
Open
6V
GND
WAVEFORM 1 : PROPAGATION DELAYS
(f=1MHz; 50% duty cycle)
5/9
单片机
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