TC74HC245AP/AF,640AP/AF
TOSHIBA CMOS Digital Integrated Circuit
Silicon Monolithic
TC74HC245AP,TC74HC245AF,TC74HC640AP,TC74HC640AF
Octal Bus Transceiver
TC74HC245AP/AF
TC74HC640AP/AF
3-State, Non-Inverting
3-State, Inverting
TC74HC245AP, TC74HC640AP
The TC74HC245A, 640A are high speed CMOS OCTAL BUS
TRANSCEIVERs fabricated with silicon gate C2MOS technology.
They achieve the high speed operation similar to equivalent
LSTTL while maintaining the CMOS low power dissipation.
They are intended for two-way asynchronous communication
between data busses. The direction of data transmission is
determined by the level of the DIR input.
The enable input (
G
) can be used to disable the device so that
the busses are effectively isolated.
All inputs are equipped with protection circuits against static
discharge or transient excess voltage.
TC74HC245AF, TC74HC640AF
Features (Note 1)(Note 2)
•
•
•
•
•
•
•
•
High speed: t
pd
= 10 ns (typ.) at V
CC
= 5 V
Low power dissipation: I
CC
= 4
μA
(max) at Ta = 25°C
High noise immunity: V
NIH
= V
NIL
= 28% V
CC
(min)
Output drive capability: 15 LSTTL loads
Symmetrical output impedance: |I
OH
| = I
OL
= 6 mA (min)
Balanced propagation delays: t
pLH
∼
t
pHL
−
Wide operating voltage range: V
CC
(opr) = 2~6 V
Pin and function compatible with 74LS245/640
Note 1: Do not apply a signal to any bus terminal when it is in the output mode. Damage may result.
Note 2: All floating (high impedance) bus terminals must have their input levels fixed by means of pull up or pull
down resistors.
Weight
DIP20-P-300-2.54A
SOP20-P-300-1.27A
: 1.30 g (typ.)
: 0.22 g (typ.)
1
2007-10-01
TC74HC245AP/AF,640AP/AF
Pin Assignment
TC74HC245A
TC74HC640A
IEC Logic Symbol
TC74HC245A
TC74HC640A
Truth Table
Inputs
Function
Outputs
G
L
L
H
DIR
L
H
X
A Bus
Output
Input
Z
B Bus
Input
Output
HC245A
A
=
B
B
=
A
Z
HC640A
A
=
B
B
=
A
Z
X: “H” or “L”
Z: High impedance
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2007-10-01
TC74HC245AP/AF,640AP/AF
Absolute Maximum Ratings (Note 1)
Characteristics
Supply voltage range
DC input voltage
DC output voltage
Input diode current
Output diode current
DC output current
DC V
CC
/ground current
Power dissipation
Storage temperature
Symbol
V
CC
V
IN
V
OUT
I
IK
I
OK
I
OUT
I
CC
P
D
T
stg
Rating
−
0.5~7
−
0.5~V
CC
+
0.5
−
0.5~V
CC
+
0.5
±
20
±
20
±
35
±
75
Unit
V
V
V
mA
mA
mA
mA
mW
°C
500 (DIP) (Note 2)/180 (SOP)
−
65~150
Note 1: 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 2: 500 mW in the range of Ta
= −40
to 65°C. From Ta
=
65 to 85°C a derating factor of
−10
mW/°C shall be
applied until 300 mW.
Operating Ranges
(Note)
Characteristics
Supply voltage
Input voltage
Output voltage
Operating temperature
Symbol
V
CC
V
IN
V
OUT
T
opr
Rating
2~6
0~V
CC
0~V
CC
−
40~85
Unit
V
V
V
°C
0~1000 (V
CC
=
2.0 V)
Input rise and fall time
t
r
, t
f
0~500 (V
CC
=
4.5 V)
0~400 (V
CC
=
6.0 V)
ns
Note:
The operating ranges must be maintained to ensure the normal operation of the device. Unused inputs and
bus inputs must be tied to either VCC or GND. Please connect both bus inputs and the bus outputs with
VCC or GND when the I/O of the bus terminal changes by the function. In this case, please note that the
output is not short-circuited.
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2007-10-01
TC74HC245AP/AF,640AP/AF
Electrical Characteristics
DC Characteristics
Characteristics
Symbol
Test Condition
V
CC
(V)
2.0
High-level input
voltage
V
IH
⎯
Ta
=
25°C
Min
1.50
3.15
4.20
⎯
⎯
⎯
Ta
= −
40~85°C
Max
⎯
⎯
⎯
Typ.
⎯
⎯
⎯
⎯
⎯
⎯
Min
1.50
3.15
4.20
⎯
⎯
⎯
Max
⎯
⎯
⎯
Unit
4.5
6.0
2.0
V
0.50
1.35
1.80
⎯
⎯
⎯
⎯
⎯
0.50
1.35
1.80
⎯
⎯
⎯
⎯
⎯
Low-level input
voltage
V
IL
⎯
4.5
6.0
2.0
V
1.9
4.4
5.9
4.18
5.68
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
2.0
4.5
6.0
4.31
5.80
0.0
0.0
0.0
0.17
0.18
⎯
⎯
⎯
1.9
4.4
5.9
4.13
5.63
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
I
OH
= −
20
μ
A
High-level output
voltage
V
OH
V
IN
=
V
IH
or V
IL
I
OH
= −
6 mA
I
OH
= −
7.8 mA
I
OL
=
20
μ
A
Low-level output
voltage
V
OL
V
IN
=
V
IH
or V
IL
I
OL
=
6 mA
I
OL
=
7.8 mA
3-state output
off-state current
Input leakage
current
Quiescent supply
current
I
OZ
I
IN
I
CC
V
IN
=
V
IH
or V
IL
V
OUT
=
V
CC
or GND
V
IN
=
V
CC
or GND
V
IN
=
V
CC
or GND
4.5
6.0
4.5
6.0
2.0
4.5
6.0
4.5
6.0
6.0
6.0
6.0
V
0.1
0.1
0.1
0.26
0.26
±
0.5
±
0.1
0.1
0.1
0.1
0.33
0.33
±
5.0
±
1.0
μ
A
μ
A
μ
A
V
4.0
40.0
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2007-10-01
TC74HC245AP/AF,640AP/AF
AC Characteristics
(input: t
r
=
t
f
=
6 ns)
Characteristics
Symbol
Test Condition
CL (pF) V
CC
(V)
2.0
⎯
Ta
=
25°C
Min
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
Ta
= −
40~85°C
Max
60
12
10
90
18
15
120
24
20
150
30
26
180
36
31
150
30
26
10
⎯
⎯
⎯
Typ.
52
7
6
33
12
10
48
16
14
48
16
14
63
21
18
37
17
15
5
13
39
37
Min
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
⎯
Max
75
15
13
115
23
20
150
30
26
190
38
32
225
45
38
190
38
32
10
⎯
⎯
⎯
Unit
Output transition time
t
TLH
t
THL
50
4.5
6.0
2.0
ns
50
Propagation delay
time
t
pLH
t
pHL
⎯
4.5
6.0
2.0
ns
150
4.5
6.0
2.0
50
3-state output enable
time
t
pZL
t
pZH
R
L
=
1k
Ω
150
4.5
6.0
2.0
4.5
6.0
ns
3-state output disable
time
Input capacitance
Bus input capacitance
Power dissipation
capacitance
t
pLZ
t
pHZ
C
IN
C
OUT
C
PD
2.0
R
L
=
1k
Ω
50
4.5
6.0
DIR, G
An, Bn
TC74HC245A
ns
pF
pF
pF
(Note) TC74HC640A
Note:
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
½V
CC
½f
IN
+
I
CC
/8 (per bit)
5
2007-10-01
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