74LCX240FT
CMOS Digital Integrated Circuits Silicon Monolithic
74LCX240FT
1. Functional Description
•
Low-Voltage Octal Bus Buffer (Inverted) with 5-V Tolerant Inputs and Outputs
2. General
The 74LCX240FT is a high-performance CMOS octal bus
buffer. Designed for use in 3.3-V systems, it achieves high-speed
operation while maintaining the CMOS low power dissipation.
The device is designed for low-voltage (3.3 V) V
CC
applications,
but it could be used to interface to 5 V supply environment for
both inputs and outputs.
The 74LCX240FT is an inverting 3-state buffer having
two active-low output enables. This device is designed to be used
with 3-state memory address drivers, etc.
All inputs are equipped with protection circuits against static
discharge.
3. Features
(1)
(2)
(3)
(4)
(5)
Low-voltage operation: V
CC
= 1.65 to 3.6 V
High-speed operation: t
pd
= 6.5 ns (max) (V
CC
= 3.0 to 3.6 V)
Output current: |I
OH
|/I
OL
= 24 mA (min) (V
CC
= 3.0 V)
Power-down protection provided on all inputs and outputs
Pin and function compatible with the 74 series
(74LVC/ALVC/ etc.) 240 type
4. Packaging
TSSOP20B
Start of commercial production
1
2013-10
2014-08-19
Rev.3.0
74LCX240FT
5. Pin Assignment
6. Marking
7. IEC Logic Symbol
2
2014-08-19
Rev.3.0
74LCX240FT
8. Truth Table
Inputs OE
L
L
H
Inputs An
L
H
X
Outputs
H
L
Z
X:
Z:
Don't care
High impedance
9. Absolute Maximum Ratings (Note)
Characteristics
Supply voltage
Input voltage
Output voltage
Input diode current
Output diode current
Output current
Power dissipation
V
CC
/ground current
Storage temperature
Symbol
V
CC
V
IN
V
OUT
I
IK
I
OK
I
OUT
P
D
I
CC
/I
GND
T
stg
(Note 3)
(Note 1)
(Note 2)
Note
Rating
-0.5 to 6.5
-0.5 to 6.5
-0.5 to 6.5
-0.5 to V
CC
+ 0.5
-50
±50
±50
180
±100
-65 to 150
mA
mA
mA
mW
mA
Unit
V
V
V
Note:
Exceeding any of the absolute maximum ratings, even briefly, lead to deterioration in IC performance or even
destruction.
Using continuously under heavy loads (e.g. the application of high temperature/current/voltage and the
significant change in temperature, etc.) may cause this product to decrease in the reliability significantly even
if the operating conditions (i.e. operating temperature/current/voltage, etc.) are within the absolute maximum
ratings and the operating ranges.
Please design the appropriate reliability upon reviewing the Toshiba Semiconductor Reliability Handbook
(“Handling Precautions”/“Derating Concept and Methods”) and individual reliability data (i.e. reliability test report
and estimated failure rate, etc).
Note 1: Output in OFF state.
Note 2: High (H) or Low (L) state. I
OUT
absolute maximum rating must be observed.
Note 3: V
OUT
< GND, V
OUT
> V
CC
3
2014-08-19
Rev.3.0
74LCX240FT
10. Operating Ranges (Note)
Characteristics
Supply voltage
Input voltage
Output voltage
Output current
Operating temperature
Input rise and fall times
Symbol
V
CC
(Note 1)
V
IN
V
OUT
I
OH
,I
OL
T
opr
dt/dv
(Note 6)
(Note 2)
(Note 3)
(Note 4)
(Note 5)
Note
Rating
1.65 to 3.6
1.5 to 3.6
0 to 5.5
0 to 5.5
0 to V
CC
±24
±12
-40 to 85
0 to 10
ns/V
mA
V
V
Unit
V
The operating ranges must be maintained to ensure the normal operation of the device.
Unused inputs must be tied to either V
CC
or GND.
Note 1: Data retention only.
Note 2: Output in OFF state.
Note 3: High or low state
Note 4: V
CC
= 3.0 to 3.6 V
Note 5: V
CC
= 2.7 to 3.0 V
Note 6: V
IN
=0.8 to 2.0 V , V
CC
= 3.0 V
Note:
11. Electrical Characteristics
85
11.1. DC Characteristics (Unless otherwise specified, T
a
= -40 to 85
)
Characteristics
High-level input voltage
Symbol
V
IH
Test Condition
V
CC
(V)
Min
Max
V
CC
×
0.1
0.7
0.8
0.2
0.45
0.7
0.4
0.4
0.55
±5.0
±5.0
10.0
10.0
±10.0
500
µA
µA
µA
µA
µA
V
V
V
Unit
V
1.65 to 2.3 V
CC
×
0.9
2.3 to 2.7
2.7 to 3.6
Low-level input voltage
V
IL
1.65 to 2.3
2.3 to 2.7
2.7 to 3.6
High-level output voltage
V
OH
V
IN
= V
IH
or V
IL
I
OH
= -100
µA
I
OH
= -4 mA
I
OH
= -8 mA
I
OH
= -12 mA
I
OH
= -18 mA
I
OH
= -24 mA
Low-level output voltage
V
OL
V
IN
= V
IH
or V
IL
I
OL
= 100
µA
I
OL
= 4 mA
I
OL
= 8 mA
I
OL
= 12 mA
I
OL
= 16 mA
I
OL
= 24 mA
Input leakage current
3-state output OFF-state
leakage current
Power-OFF leakage current
Quiescent supply current
Quiescent supply current
I
IN
I
OZ
I
OFF
I
CC
∆I
CC
V
IN
= 0 to 5.5 V
V
IN
= V
IH
or V
IL
V
OUT
= 0 to 5.5 V
V
IN
/V
OUT
= 5.5 V
V
IN
= V
CC
or GND
V
IN
/V
OUT
= 3.6 to 5.5 V
V
IH
= V
CC
- 0.6 V
(per input)
1.65 to 3.6
1.65
2.3
2.7
3.0
3.0
1.65 to 3.6
1.65
2.3
2.7
3.0
3.0
1.65 to 3.6
1.65 to 3.6
0
1.65 to 3.6
1.65 to 3.6
2.7 to 3.6
1.7
2.0
V
CC
- 0.2
1.05
1.7
2.2
2.4
2.2
4
2014-08-19
Rev.3.0
74LCX240FT
11.2. AC Characteristics (Unless otherwise specified, T
a
= -40 to 85
)
85
Characteristics
Propagation delay time
Symbol
t
PLH
,t
PHL
Note
Test Condition
See 11.5 AC Test Circuit,
Table 11.5.1, Fig. 11.6.1, Table
11.6.1
V
CC
(V)
1.8
±
0.15
2.5
±
0.2
2.7
3.3
±
0.3
3-state output enable time
t
PZL
,t
PZH
See 11.5 AC Test Circuit,
Table 11.5.1, Fig. 11.6.2, Table
11.6.1
1.8
±
0.15
2.5
±
0.2
2.7
3.3
±
0.3
3-state output disable time
t
PLZ
,t
PHZ
See 11.5 AC Test Circuit,
Table 11.5.1, Fig. 11.6.2, Table
11.6.1
1.8
±
0.15
2.5
±
0.2
2.7
3.3
±
0.3
Output skew
t
osLH
,t
osHL
(Note 1)
2.7
3.3
±
0.3
Min
1.5
1.5
1.5
Max
25.0
8.5
7.5
6.5
32.0
16.0
9.0
8.0
30.0
15.0
8.0
7.0
1.0
ns
ns
ns
Unit
ns
Note 1: Parameter guaranteed by design. (t
osLH
= |t
PLH
m - t
PLH
n|, t
osHL
= |t
PHL
m - t
PHL
n|)
25
11.3. Dynamic Switching Characteristics (Unless otherwise specified, T
a
= 25
, Input: t
r
= t
f
= 2.5 ns, C
L
= 50 pF, R
L
= 500
Ω
)
Characteristics
Quiet output maximum dynamic V
OL
Quiet output minimum dynamic V
OL
Symbol
V
OLP
Test Condition
V
IH
= 3.3 V, V
IL
= 0 V
V
CC
(V)
3.3
3.3
Typ.
0.8
0.8
Unit
V
V
|V
OLV
| V
IH
= 3.3 V, V
IL
= 0 V
25
11.4. Capacitive Characteristics (Unless otherwise specified, T
a
= 25
)
Characteristics
Input capacitance
Output capacitance
Power dissipation capacitance
Symbol
C
IN
C
OUT
C
PD
(Note 1) f
IN
= 10 MHz
Note
Test Condition
V
CC
(V)
3.3
3.3
3.3
Typ.
7
8
25
Unit
pF
pF
pF
Note 1: C
PD
is defined as the value of the internal equivalent capacitance which is calculated from the operating current
consumption without load. Average operating current can be obtained by the equation.
I
CC(opr)
= C
PD
×
V
CC
×
f
IN
+ I
CC
/8 (per bit)
5
2014-08-19
Rev.3.0
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