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DM74AS245N

Part # DM74AS245N
Description IC TRANSCVR TRI-ST 8BIT 20DIP
Category IC
Availability In Stock
Qty 18
Qty Price
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Manufacturer Available Qty
National Semiconductor Corp
Date Code: 9324
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Technical Document


DISCLAIMER: The information provided herein is solely for informational purposes. Customers must be aware of the suitability of this product for their application, and consider that variable factors such as Manufacturer, Product Category, Date Codes, Pictures and Descriptions may differ from available inventory.

© 2000 Fairchild Semiconductor Corporation DS006299 www.fairchildsemi.com
October 1986
Revised February 2000
DM74AS245 Octal Bus Transceiver with 3-STATE Outputs
DM74AS245
Octal Bus Transceiver with 3-STATE Outputs
General Description
This advanced Schottky device contains 8 pairs of
3-STATE logic elements configured as octal bus transceiv-
ers. These circuits are designed for use in memory, micro-
processor systems and in asynchronous bidirectional data
buses. Two way communication between buses is con-
trolled by the (DIR) input. Data transmits either from the A
bus to the B bus or from the B bus to the A bus. Both the
driver and receiver outputs can be disabled via the (G
)
enable input which causes outputs to enter the high imped-
ance mode so that the buses are effectively isolated.
Features
Advanced oxide-isolated, ion-implanted Schottky
TTL process
Non-inverting logic output
3-STATE outputs independently controlled on
A and B buses
Low output impedance to drive terminated transmission
lines to 133
Switching response specified into 500/50 pF
Specified to interface with CMOS at V
OH
= V
CC
2V
PNP inputs reduce input loading
Switching specifications guaranteed over full
temperature and V
CC
range
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram Function Table
Order Number Package Number Package Description
DM74AS245WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74AS245SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74AS245N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Control
Inputs Operation
G
DIR
L L B Data to A Bus
L H A Data to B Bus
H X Hi-Z
www.fairchildsemi.com 2
DM74AS245
Absolute Maximum Ratings(Note 1)
Note 1: The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Electrical Characteristics
over recommended operating free air temperature range
Switching Characteristics
over recommended operating free air temperature range
Supply Voltage, V
CC
7V
Input Voltage
Control Inputs 7V
I/O Ports 5.5V
Operating Free Air Temperature Range 0°C to 70°C
Storage Temperature Range 65°C to +150°C
Typical θ
JA
N Package 51.5°C/W
M Package 76.0°C/W
Symbol Parameter Min Typ Max Units
V
CC
Supply Voltage 4.5 5 5.5 V
V
IH
HIGH Level Input Voltage 2 V
V
IL
LOW Level Input Voltage 0.8 V
I
OH
HIGH Level Output Current 15 mA
I
OL
LOW Level Output Current 48 mA
T
A
Free Air Operating Temperature 0 70 °C
Symbol Parameter Conditions Min Typ Max Units
V
IK
Input Clamp Voltage V
CC
= 4.5V, I
IN
= 18 mA 1.2 V
V
OH
HIGH Level Output V
CC
= 4.5V, I
OH
= 3 mA 2.4 3.2
Voltage V
CC
= 4.5V, I
OH
= 15 mA 2 2.3 V
I
OH
= 2 mA, V
CC
= 4.5V to 5.5V V
CC
2
V
OL
LOW Level Output Voltage V
CC
= 4.5V, I
OL
= Max 0.35 0.55 V
I
I
Input Current at Max V
CC
= 5.5V, V
IN
= 7V,
0.1 mA
Input Voltage (V
IN
= 5.5V for A or B Ports)
I
IH
HIGH Level Input Current V
CC
= 5.5V, Control Inputs 20
µA
V
IN
= 2.7V A or B Ports 70
I
IL
LOW Level Input Current V
CC
= 5.5V, Control Inputs 0.5
mA
V
IN
= 0.4V A or B Ports 0.75
I
O
Output Drive Current V
CC
= 5.5V, V
OUT
= 2.25V 50 150 mA
I
CC
Supply Current V
CC
= 5.5V Output HIGH 62 97
Output LOW 95 149 mA
3-STATE 79 123
Symbol Parameter Conditions From To Min Max Units
t
PLH
Propagation Delay Time V
CC
= 4.5V to 5.5V,
A or B B or A 2 7.5 ns
HIGH-to-LOW Level Output R
1
= R
2
= 500,
t
PHL
Propagation Delay Time C
L
= 50 pF
A or B B or A 2 7 ns
HIGH-to-LOW Level Output
t
PZL
Output Enable Time to LOW Level G A or B 2 8.5 ns
t
PZH
Output Enable Time to HIGH Level G A or B 2 9 ns
t
PLZ
Output Disable Time from LOW Level G A or B 2 9.5 ns
t
PHZ
Output Disable Time from HIGH Level G A or B 2 5.5 ns
3 www.fairchildsemi.com
DM74AS245
Physical Dimensions inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
Package Number M20B
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