74VHC245FT
CMOS Digital Integrated Circuits Silicon Monolithic
74VHC245FT
1. Functional Description
•
Octal Bus Transceiver
2. General
The 74VHC245FT is an advanced high speed CMOS OCTAL BUS TRANSCEIVER fabricated with silicon gate
C
2
MOS technology.
It achieves the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS
low power dissipation.
It is 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.
3. Features (Note)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
AEC-Q100 (Rev. H) (Note 1)
Wide operating temperature range: T
opr
= -40 to 125
High speed: Propagation delay time = 4.0 ns (typ.) at V
CC
= 5.0 V
Low power dissipation: I
CC
= 4.0
µA
(max) at T
a
= 25
High noise immunity: V
NIH
= V
NIL
= 28 % V
CC
(min)
Balanced propagation delays: t
PLH
≈
t
PHL
Wide operating voltage range: V
CC(opr)
= 2.0 V to 5.5 V
Low noise: V
OLP
= 1.0 V (max)
(9) Pin and function compatible with the 74 series (74AC/HC/AHC etc.) 245 type.
Note: Do not apply a signal to any bus terminal when it is in the output mode. Damage may result.
All floating (high impedance) bus terminals must have their input levels fixed by means of pull up or pull down
resistors.
A parasitic diode is formed between the bus and V
CC
terminals. Therefore bus terminal can not be used to
interface 5 V to 3 V systems directly.
Note 1: This device is compliant with the reliability requirements of AEC-Q100. For details, contact your Toshiba sales
representative.
4. Packaging
TSSOP20B
Start of commercial production
©2017 Toshiba Corporation
1
2013-04
2017-02-22
Rev.4.0
74VHC245FT
5. Pin Assignment
6. Marking
7. IEC Logic Symbol
©2017 Toshiba Corporation
2
2017-02-22
Rev.4.0
74VHC245FT
8. Truth Table
Input G
L
L
H
Input DIR
L
H
X
A BUS
Output
Input
Z
B BUS
Input
Output
Z
Output
A=B
B=A
Z
X:
Z:
Don't care
High impedance
9. Absolute Maximum Ratings (Note)
Characteristics
Supply voltage
Input voltage(DIR,G)
Bus I/O voltage
Input diode current
Output diode current
Output current
V
CC
/ground current
Power dissipation
Storage temperature
Symbol
V
CC
V
IN
V
I/O
I
IK
I
OK
I
OUT
I
CC
P
D
T
stg
(Note 1)
Note
Rating
-0.5 to 7.0
-0.5 to 7.0
-0.5 to V
CC
+ 0.5
-20
±20
±25
±75
180
-65 to 150
Unit
V
V
V
mA
mA
mA
mA
mW
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: 180 mW in the range of T
a
= -40 to 85
.
From T
a
= 85 to 125
a derating factor of -3.25 mW/ shall be
applied until 50 mW.
10. Operating Ranges (Note)
Characteristics
Supply voltage
Input voltage(DIR,G)
Bus I/O voltage
Operating temperature
Input rise and fall times
Symbol
V
CC
V
IN
V
I/O
T
opr
dt/dv
V
CC
= 3.3
±
0.3 V
V
CC
= 5.0
±
0.5 V
Test Condition
Rating
2.0 to 5.5
0 to 5.5
0 to V
CC
-40 to 125
0 to 100
0 to 20
Unit
V
V
V
ns/V
Note:
The operating ranges are required to ensure the normal operation of the device. Unused inputs and bus inputs
must be tied to either V
CC
or GND. Please connect both bus inputs and the bus outputs with V
CC
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.
©2017 Toshiba Corporation
3
2017-02-22
Rev.4.0
74VHC245FT
11. Electrical Characteristics
11.1. DC Characteristics (Unless otherwise specified, T
a
= 25
)
Characteristics
High-level input voltage
Symbol
V
IH
Test Condition
V
CC
(V)
2.0
3.0 to 5.5
Low-level input voltage
V
IL
2.0
3.0 to 5.5
High-level output voltage
V
OH
V
IN
= V
IH
or V
IL
I
OH
= -50
µA
2.0
3.0
4.5
I
OH
= -4 mA
I
OH
= -8 mA
Low-level output voltage
V
OL
V
IN
= V
IH
or V
IL
I
OL
= 50
µA
3.0
4.5
2.0
3.0
4.5
I
OL
= 4 mA
I
OL
= 8 mA
3-state output OFF-state
leakage 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
= 5.5 V or GND
V
IN
= V
CC
or GND
3.0
4.5
5.5
0 to 5.5
5.5
Min
1.50
V
CC
×
0.7
1.9
2.9
4.4
2.58
3.94
Typ.
2.0
3.0
4.5
0.0
0.0
0.0
Max
0.50
V
CC
×
0.3
0.1
0.1
0.1
0.36
0.36
±0.25
±0.1
4.0
µA
µA
µA
V
V
V
Unit
V
11.2. DC Characteristics (Unless otherwise specified, T
a
= -40 to 85
)
Characteristics
High-level input voltage
Low-level input voltage
High-level output voltage
Symbol
V
IH
V
IL
V
OH
Test Condition
V
CC
(V)
2.0
3.0 to 5.5
2.0
3.0 to 5.5
V
IN
= V
IH
or V
IL
I
OH
= -50
µA
2.0
3.0
4.5
I
OH
= -4 mA
I
OH
= -8 mA
Low-level output voltage
V
OL
V
IN
= V
IH
or V
IL
I
OL
= 50
µA
3.0
4.5
2.0
3.0
4.5
I
OL
= 4 mA
I
OL
= 8 mA
3-state output OFF-state
leakage 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
= 5.5 V or GND
V
IN
= V
CC
or GND
3.0
4.5
5.5
0 to 5.5
5.5
Min
1.50
V
CC
×
0.7
1.9
2.9
4.4
2.48
3.80
Max
0.50
V
CC
×
0.3
0.1
0.1
0.1
0.44
0.44
±2.50
±1.0
40.0
µA
µA
µA
V
V
V
Unit
V
©2017 Toshiba Corporation
4
2017-02-22
Rev.4.0
74VHC245FT
11.3. DC Characteristics (Unless otherwise specified, T
a
= -40 to 125
)
Characteristics
High-level input voltage
Low-level input voltage
High-level output voltage
Symbol
V
IH
V
IL
V
OH
Test Condition
V
CC
(V)
2.0
3.0 to 5.5
2.0
3.0 to 5.5
V
IN
= V
IH
or V
IL
I
OH
= -50
µA
2.0
3.0
4.5
I
OH
= -4 mA
I
OH
= -8 mA
Low-level output voltage
V
OL
V
IN
= V
IH
or V
IL
I
OL
= 50
µA
3.0
4.5
2.0
3.0
4.5
I
OL
= 4 mA
I
OL
= 8 mA
3-state output OFF-state
leakage 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
= 5.5 V or GND
V
IN
= V
CC
or GND
3.0
4.5
5.5
0 to 5.5
5.5
Min
1.50
V
CC
×
0.7
1.9
2.9
4.4
2.40
3.70
Max
0.50
V
CC
×
0.3
0.1
0.1
0.1
0.55
0.55
±10.0
±2.0
80.0
µA
µA
µA
V
V
V
Unit
V
11.4. AC Characteristics (Unless otherwise specified, T
a
= 25
, Input: t
r
= t
f
= 3 ns)
Characteristics
Propagation delay time
Symbol
t
PLH
,t
PHL
Note
Test Condition
V
CC
(V)
3.3
±
0.3
5.0
±
0.5
3-state output enable time
t
PZL
,t
PZH
R
L
= 1 kΩ
3.3
±
0.3
5.0
±
0.5
3-state output disable time
Output skew
Input capacitance
Bus I/O capacitance
Power dissipation capacitance
t
PLZ
,t
PHZ
t
osLH
,t
osHL
(Note 1)
C
IN
C
I/O
C
PD
(Note 2)
R
L
= 1 kΩ
3.3
±
0.3
5.0
±
0.5
3.3
±
0.3
5.0
±
0.5
DIR, G
An, Bn
C
L
(pF)
15
50
15
50
15
50
15
50
50
50
50
50
Min
Typ.
5.8
8.3
4.0
5.5
8.5
11.0
5.8
7.3
11.5
7.0
4
8
21
Max
8.4
11.9
5.5
7.5
13.2
16.7
8.5
10.6
15.8
9.7
1.5
1.0
10
pF
pF
pF
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|)
Note 2: 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)
©2017 Toshiba Corporation
5
2017-02-22
Rev.4.0
TI技术论坛
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
