74LCX540
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
= 8.0 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 540
LATCH-UP PERFORMANCE EXCEEDS
500mA (JESD 17)
ESD PERFORMANCE:
HBM > 2000V (MIL STD 883 method 3015);
MM > 200V
SOP
TSSOP
Table 1: Order Codes
PACKAGE
SOP
TSSOP
T&R
74LCX540MTR
74LCX540TTR
DESCRIPTION
The 74LCX540 is a low voltage CMOS OCTAL
BUS BUFFER (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.
Figure 1: Pin Connection And IEC Logic Symbols
The 3 STATE control gate operates as two input
AND such that if either G1 and G2 are high, all
eight outputs are in the high impedance state. In
order to enhance PC board layout the 74LCX540
offers a pinout having inputs and outputs on
opposite sides of the package.
It has same speed performance at 3.3V than 5V
AC/ACT family, combined with a lower power
consumption.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
September 2004
Rev. 3
1/12
74LCX540
Figure 2: Input And Output Equivalent Circuit
Table 2: Pin Description
PIN N°
1, 19
2, 3, 4, 5, 6,
7, 8, 9
18, 17, 16,
15, 14, 13,
12, 11
10
20
SYMBOL
G1, G2
A1 to A8
Y1 to Y8
NAME AND FUNCTION
Output Enable Inputs
Data Inputs
Data Outputs
Table 3: Truth Table
INPUT
G1
H
X
L
L
X : Don’t Care
Z : High Impedance
OUTPUT
An
X
X
H
L
Yn
Z
Z
L
H
G2
X
H
L
L
GND
V
CC
Ground (0V)
Positive Supply Voltage
Table 4: 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
2/12
74LCX540
Table 5: 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
Table 6: 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
±
5
10
±
10
500
V
CC
-0.2
2.2
2.4
2.2
0.2
0.4
0.4
0.55
±
5
10
±
5
10
±
10
500
µA
µA
µA
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
I
CC
∆I
CC
2.7 to 3.6
2.7 to 3.6
3/12
74LCX540
Table 7: 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.
Table 8: 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.
9.0
8.0
9.5
8.5
8.5
7.5
1.0
Value
-55 to 125 °C
Min.
1.5
1.5
1.5
1.5
1.5
1.5
Max.
9.0
8.0
9.5
8.5
8.5
7.5
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
Table 9: 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
12
25
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 buffer)
4/12
74LCX540
Figure 3: 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
Figure 4: Waveform - Propagation Delays
(f=1MHz; 50% duty cycle)
5/12
PCB设计
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