MC74AC245
MC74ACT245
Octal Bidirectional Transceiver
with 3 State Inputs/Outputs
The MC74AC245/74ACT245 contains eight non-inverting bidirectional buffers
with 3-state outputs and is intended for bus-oriented applications. Current sinking
capability is 24 mA at both the A and B ports. The Transmit/Receive (T/R) input
determines the direction of data flow through the bidirectional transceiver. Transmit
(active-HIGH) enables data from A ports to B ports; Receive (active-LOW) enables
data from B ports to A ports. The Output Enable input, when HIGH, disables both A
and B ports by placing them in a High Z condition.
•
•
•
•
Noninverting Buffers
Bidirectional Data Path
A and B Outputs Source/Sink 24 mA
′ACT245
Has TTL Compatible Inputs
VCC
20
OE
19
B0
18
B1
17
B2
16
B3
15
B4
14
B5
13
B6
12
B7
11
OCTAL BIDIRECTIONAL
TRANSCEIVER
WITH 3-STATE
INPUTS/OUTPUTS
N SUFFIX
CASE 738-03
PLASTIC
DW SUFFIX
CASE 751D-04
PLASTIC
1
T/R
2
A0
3
A1
4
A2
5
A3
6
A4
7
A5
8
A6
9
A7
10
GND
PIN NAMES
OE
T/R
A0–A7
B0–B7
Output Enable Input
Transmit/Receive Input
Side A 3-State Inputs or 3-State Outputs
Side B 3-State Inputs or 3-State Outputs
TRUTH TABLES
Inputs
Outputs
OE
L
L
H
T/R
L
H
X
Bus B Data to Bus A
Bus A Data to Bus B
High Z State
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
FACT DATA
5-1
MC74AC245 MC74ACT245
MAXIMUM RATINGS*
Symbol
VCC
Vin
Vout
Iin
Iout
ICC
Tstg
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage (Referenced to GND)
DC Output Voltage (Referenced to GND)
DC Input Current, per Pin
DC Output Sink/Source Current, per Pin
DC VCC or GND Current per Output Pin
Storage Temperature
Value
–0.5 to +7.0
–0.5 to VCC +0.5
–0.5 to VCC +0.5
±20
±50
±50
–65 to +150
Unit
V
V
V
mA
mA
mA
°C
* Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended
Operating Conditions.
RECOMMENDED OPERATING CONDITIONS
Symbol
VCC
Vin, Vout
Supply Voltage
DC Input Voltage, Output Voltage (Ref. to GND)
VCC @ 3.0 V
tr, tf
Input Rise and Fall Time (Note 1)
′AC
Devices except Schmitt Inputs
VCC @ 4.5 V
VCC @ 5.5 V
tr, tf
TJ
TA
IOH
IOL
Input Rise and Fall Time (Note 2)
′ACT
Devices except Schmitt Inputs
Junction Temperature (PDIP)
Operating Ambient Temperature Range
Output Current — High
Output Current — Low
–40
25
VCC @ 4.5 V
VCC @ 5.5 V
Parameter
′AC
′ACT
Min
2.0
4.5
0
150
40
25
10
ns/V
8.0
140
85
–24
24
°C
°C
mA
mA
ns/V
Typ
5.0
5.0
Max
6.0
5.5
VCC
V
Unit
V
1. Vin from 30% to 70% VCC; see individual Data Sheets for devices that differ from the typical input rise and fall times.
2. Vin from 0.8 V to 2.0 V; see individual Data Sheets for devices that differ from the typical input rise and fall times.
FACT DATA
5-2
MC74AC245 MC74ACT245
DC CHARACTERISTICS
74AC
Symbol
Parameter
VCC
(V)
TA = +25°C
Typ
VIH
Minimum High Level
Input Voltage
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
VOL
Maximum Low Level
Output Voltage
3.0
4.5
5.5
3.0
4.5
5.5
IIN
IOZT
Maximum Input
Leakage Current
Maximum
3-State
Current
†Minimum Dynamic
Output Current
Maximum Quiescent
Supply Current
5.5
0.002
0.001
0.001
1.5
2.25
2.75
1.5
2.25
2.75
2.99
4.49
5.49
74AC
TA =
–40°C to +85°C
Unit
Conditions
Guaranteed Limits
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.56
3.86
4.86
0.1
0.1
0.1
0.36
0.36
0.36
±0.1
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.46
3.76
4.76
0.1
0.1
0.1
0.44
0.44
0.44
±1.0
V
VOUT = 0.1 V
or VCC – 0.1 V
VOUT = 0.1 V
or VCC – 0.1 V
IOUT = –50
µA
V
*VIN = VIL or VIH
–12 mA
IOH
–24 mA
–24 mA
IOUT = 50
µA
V
*VIN = VIL or VIH
12 mA
IOL
24 mA
24 mA
VI = VCC, GND
VI (OE) = VIL, VIH
VI = VCC, GND
VO = VCC, GND
VOLD = 1.65 V Max
VOHD = 3.85 V Min
VIN = VCC or GND
VIL
Maximum Low Level
Input Voltage
V
VOH
Minimum High Level
Output Voltage
V
V
µA
5.5
5.5
5.5
5.5
±0.6
±6.0
75
–75
µA
mA
mA
µA
IOLD
IOHD
ICC
8.0
80.0
* All outputs loaded; thresholds on input associated with output under test.
† Maximum test duration 2.0 ms, one output loaded at a time.
Note: IIN and ICC @ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V VCC.
FACT DATA
5-3
MC74AC245 MC74ACT245
AC CHARACTERISTICS
(For Figures and Waveforms — See Section 3)
74AC
Symbol
Parameter
VCC*
(V)
Min
tPLH
tPHL
tPZH
tPZL
tPHZ
tPLZ
Propagation Delay
An to Bn or Bn to An
Propagation Delay
An to Bn or Bn to An
Output Enable Time
Output Enable Time
Output Disable Time
Output Disable Time
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
1.5
1.5
1.5
1.5
2.5
1.5
2.5
1.5
2.0
1.5
2.0
1.5
TA = +25°C
CL = 50 pF
Typ
5.0
3.5
5.0
3.5
7.0
5.0
7.5
5.5
6.5
5.5
7.0
5.5
Max
8.5
6.5
8.5
6.0
11.5
8.5
12.0
9.0
12.0
9.0
11.5
9.0
74AC
TA = –40°C
to +85°C
CL = 50 pF
Min
1.0
1.0
1.0
1.0
2.0
1.0
2.0
1.0
1.0
1.0
1.5
1.0
Max
9.0
7.0
9.0
7.0
12.5
9.0
13.5
9.5
12.5
10.0
13.0
10.0
ns
ns
ns
ns
ns
ns
3-5
3-5
3-7
3-8
3-7
3-8
Unit
Fig.
No.
* Voltage Range 3.3 V is 3.3 V
±0.3
V.
Voltage Range 5.0 V is 5.0 V
±0.5
V.
DC CHARACTERISTICS
74ACT
Symbol
Parameter
VCC
(V)
TA = +25°C
Typ
VIH
VIL
VOH
Minimum High Level
Input Voltage
Maximum Low Level
Input Voltage
Minimum High Level
Output Voltage
4.5
5.5
4.5
5.5
4.5
5.5
4.5
5.5
VOL
Maximum Low Level
Output Voltage
4.5
5.5
4.5
5.5
IIN
∆I
CCT
IOZT
Maximum Input
Leakage Current
Additional Max. ICC/Input
Maximum
3-State
Current
†Minimum Dynamic
Output Current
Maximum Quiescent
Supply Current
5.5
5.5
5.5
5.5
5.5
5.5
8.0
0.6
±0.6
0.001
0.001
1.5
1.5
1.5
1.5
4.49
5.49
74ACT
TA =
–40°C to +85°C
Unit
Conditions
Guaranteed Limits
2.0
2.0
0.8
0.8
4.4
5.4
3.86
4.86
0.1
0.1
0.36
0.36
±0.1
2.0
2.0
0.8
0.8
4.4
5.4
3.76
4.76
0.1
0.1
0.44
0.44
±1.0
1.5
±6.0
75
–75
80.0
V
V
V
VOUT = 0.1 V
or VCC – 0.1 V
VOUT = 0.1 V
or VCC – 0.1 V
IOUT = –50
µA
*VIN = VIL or VIH
–24 mA
IOH
–24 mA
IOUT = 50
µA
*VIN = VIL or VIH
24 mA
IOL
24 mA
VI = VCC, GND
VI = VCC – 2.1 V
VI (OE) = VIL, VIH
VI = VCC, GND
VO = VCC, GND
VOLD = 1.65 V Max
VOHD = 3.85 V Min
VIN = VCC or GND
V
V
V
µA
mA
µA
mA
mA
µA
IOLD
IOHD
ICC
* All outputs loaded; thresholds on input associated with output under test.
† Maximum test duration 2.0 ms, one output loaded at a time.
FACT DATA
5-4
MC74AC245 MC74ACT245
AC CHARACTERISTICS
(For Figures and Waveforms — See Section 3)
74ACT
Symbol
Parameter
VCC*
(V)
Min
tPLH
tPHL
tPZH
tPZL
tPHZ
tPLZ
Propagation Delay
An to Bn or Bn to An
Propagation Delay
An to Bn or Bn to An
Output Enable Time
Output Enable Time
Output Disable Time
Output Disable Time
5.0
5.0
5.0
5.0
5.0
5.0
1.5
1.5
1.5
1.5
1.5
2.0
TA = +25°C
CL = 50 pF
Typ
4.0
4.0
5.0
5.5
5.5
5.0
Max
7.5
8.0
10
10
10
10
74ACT
TA = –40°C
to +85°C
CL = 50 pF
Min
1.5
1.0
1.5
1.5
1.0
1.5
Max
8.0
9.0
11.0
12.0
11.0
11.0
ns
ns
ns
ns
ns
ns
3-5
3-5
3-7
3-8
3-7
3-8
Unit
Fig.
No.
* Voltage Range 5.0 V is 5.0 V
±0.5
V.
CAPACITANCE
Symbol
CIN
CI/O
CPD
Input Capacitance
Input/Output Capacitance
Power Dissipation Capacitance
Parameter
Value
Typ
4.5
15
45
Unit
pF
pF
pF
Test Conditions
VCC = 5.0 V
VCC = 5.0 V
VCC = 5.0 V
FACT DATA
5-5
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