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HD74BC245A
Octal Bus Transceivers With 3 State Outputs
ADE-205-008A (Z)
Rev. 1
March 1993
Description
The HD74BC245A provides high drivability and operation equal to or better than high speed bipolar
standard logic IC by using Bi-CMOS process. The device features low power dissipation that is about 1/5
of high speed bipolar logic IC, when the frequency is 10 MHz. The device has ten buffers with three state
outputs in a 20 pin package. Each device has an active low enable input G and a direction control input
DiR. When DiR is high, data flows from the A inputs to the B outputs. When DiR is low, data flows from
the B inputs to the A outputs. When G is high, disables both A and B ports by placing then in a high
impedance.
Features
• Input/Output are at high impedance state when power supply is off.
• Built in input pull up circuit can make input pins be open, when not used.
• TTL level input
• Wide operating temperature range
Ta = –40 to + 85°C
Function Table
Control Inputs
G DiR Operation
L L B data to A bus
L H A data to B bus
HX Z
H : High level
L : Low level
Z : High impedance
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HD74BC245A
Pin Arrangement
DiR
A1
A2
A3
A4
A5
A6
A7
A8
GND
1
2
3
4
5
6
7
8
9
10
19
18
17
16
15
14
13
12
11
20
V
G
B1
B2
B3
B4
B5
B6
B7
B8
CC
(Top view)
Absolute Maximum Ratings
Item Symbol Rating Unit
Supply voltage V
Input diode current I
Input voltage V
Output voltage V
Off state output voltage V
CC
IK
IN
OUT
OUT(off)
Storage temperature Tstg –65 to +150 °C
Note: 1. The absolute maximum ratings are values which must not individually be exceeded, and
furthermore, no two of which may be realized at the same time.
–0.5 to +7.0 V
±30 mA
–0.5 to +7.5 V
–0.5 to +7.5 V
–0.5 to +5.5 V
2
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HD74BC245A
Recommended Operating Conditions
Item Symbol Min Typ Max Unit
Supply voltage V
Input voltage V
Output voltage V
CC
IN
OUT
Operating temperature Topr –40 — 85 °C
Input rise/fall time*
1
tr, t
f
Note: 1. This item guarantees maximum limit when one input switches.
Waveform: Refer to test circuit of switching characteristics.
Logic Diagram
DiR
A1 B1
4.5 5.0 5.5 V
0—VCCV
0—VCCV
0 — 8 ns/V
G
A2
A3
A4
A5
A6
A7
A8
B2
B3
B4
B5
B6
B7
B8
3
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HD74BC245A
Electrical Characteristics (Ta = –40°C to +85°C)
Item Symbol VCC(V) Min Max Unit Test Conditions
Input voltage V
Output voltage V
IH
V
IL
OH
4.5 2.4 — V IOH = –3 mA
4.5 2.0 — V IOH = –15 mA
V
OL
4.5 — 0.5 V IOL = 48 mA
4.5 — 0.55 V IOL = 64 mA
Input diode voltage V
Input current I
IK
I
4.5 — –1.2 V IIN = –18 mA
5.5 — –250 µAV
5.5 — 100 µA An or Bn, VIN = 5.5 V
5.5 — 1.0 µA DiR or G, VIN = 5.5 V
5.5 — 100 µA DiR or G, VIN = 7.0 V
Short circuit output current*1I
Off state output current I
Supply current I
OS
OZH
I
OZL
CCL
I
CCH
I
CCZ
2
I
*
CCT
5.5 –100 –225 mA VO = 0 V, VIN = 5.5 V
5.5 — –100 µAV
5.5 — –250 µAV
5.5 — 31.5 mA VIN = 0 or 5.5 V
5.5 — 0.5 mA VIN = 0 or 5.5 V
5.5 — 4.5 mA VIN = 0 or 5.5 V
5.5 — 1.5 mA VIN = 3.4 or 0.5 V
Notes : 1. Not more than one output should be shorted at a time and duration of the short circuit should not
exceed one second.
2. When input by the TTL level, it shows I
2.0 — V
— 0.8 V
increase at per one input pin.
CC
= 0 V
IN
= 2.7 V
O
= 0.5 V
O
All outputs is “L”
All outputs is “H”
All outputs is “Z”
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Switching Test Method (CL = 50 pF)
HD74BC245A
Ta = 25°C
V
= 5.0 V
CC
Ta = –40 to 85°C
VCC = 5.0 V ±10%
Item Symbol Min Max Min Max Unit Test Conditions
Propagation delay time t
Output enable time t
Output disable time t
Input capacitanse C
Output capacitance C
PLH
t
PHL
t
PLH
t
PHL
ZH
t
ZL
t
ZH
t
ZL
HZ
t
LZ
t
HZ
t
LZ
IN
I/O
3.0 6.0 3.0 7.0 ns An to Bn
3.0 6.0 3.0 7.0
3.0 6.0 3.0 7.0 ns Bn to An
3.0 6.0 3.0 7.0
3.0 9.0 3.0 11.0 ns G to Bn
3.0 9.0 3.0 11.0
3.0 9.0 3.0 11.0 ns G to An
3.0 9.0 3.0 11.0
3.0 8.0 3.0 10.0 ns G to Bn
3.0 8.0 3.0 10.0
3.0 8.0 3.0 10.0 ns G to An
3.0 8.0 3.0 10.0
3.0(Typ) — pF VIN = VCC or GND
15.0(Typ) — pF V
= VCC or GND
I/O
Test Circuit
V
V
CC
Input
G
Pulse Generator
Z
out
= 50
Ω
See Function Table
DiR
Notes: 1. CL includes probe and jig capacitance.
2. A2-B2, A3-B3, A4-B4, A5-B5, A6-B6, A7-B7, A8-B8 are identical to above load circuit.
3. S1: Input-Output change switch.
4. Open: t
7 V: tZL, t
PLH
, t
, tZH, t
PHL
LZ
CC
A1
B1
HZ
S1
Output
C =
L
50 pF
50 ScopeΩ
500
450
Ω
Ω
*4
OPEN
7V
5
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HD74BC245A
Waveforms-1
Input
Output
Waveforms-2
G
1.5 V
10%
t
r
90% 90%
1.5 V
t
PLH
1.5 V
t
f
t
ZL
t
r
10%
90%90%
1.5 V
t
LZ
1.5 V
10%10%
t
f
t
1.5 V
PHL
3 V
0 V
V
OH
V
OL
3 V
0 V
3.5 V
Waveform–A
Waveform–B
Notes: 1. tr = 2.5 ns, tf = 2.5 ns
2. Input waveform: PRR = 1 MHz, duty cycle 50%
3. Waveform-A shows input conditions such that the output is “L” level when enable by the
output control.
4. Waveform-B shows input conditions such that the output is “H” level when enable by the
output control.
6
1.5 V
V
+ 0.3 V
OL
t
ZH
t
HZ
V
– 0.3 V
OH
V
OL
V
OH
1.5 V
0 V
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Package Dimensions
HD74BC245A
Unit: mm
7
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Cautions
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copyright, trademark, or other intellectual property rights for information contained in this document.
Hitachi bears no responsibility for problems that may arise with third party’s rights, including
intellectual property rights, in connection with use of the information contained in this document.
2. Products and product specifications may be subject to change without notice. Confirm that you have
received the latest product standards or specifications before final design, purchase or use.
3. Hitachi makes every attempt to ensure that its products are of high quality and reliability. However,
contact Hitachi’s sales office before using the product in an application that demands especially high
quality and reliability or where its failure or malfunction may directly threaten human life or cause risk
of bodily injury, such as aerospace, aeronautics, nuclear power, combustion control, transportation,
traffic, safety equipment or medical equipment for life support.
4. Design your application so that the product is used within the ranges guaranteed by Hitachi particularly
for maximum rating, operating supply voltage range, heat radiation characteristics, installation
conditions and other characteristics. Hitachi bears no responsibility for failure or damage when used
beyond the guaranteed ranges. Even within the guaranteed ranges, consider normally foreseeable
failure rates or failure modes in semiconductor devices and employ systemic measures such as failsafes, so that the equipment incorporating Hitachi product does not cause bodily injury, fire or other
consequential damage due to operation of the Hitachi product.
5. This product is not designed to be radiation resistant.
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products.
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