Fairchild Semiconductor DM74LS243WM, DM74LS243N, DM74LS243MX, DM74LS243M, DM74LS243WMX Datasheet
© 2000 Fairchild Semiconductor Corporation DS006412 www.fairchildsemi.com
August 1986
Revised January 2000
DM74LS243 Quadruple Bus Transceiver
DM74LS243
Quadruple Bus Transcei ver
General Description
This four data line transceiver is designed for asyn chronous two-way communication s betw een dat a buses. It can
be used to drive terminated lines down to 133Ω.
Features
■ Two-way asynchronous communication between data
buses
■ PNP inputs reduce DC loading on bus line
■ Hysteresis at data inputs improves noise margin
Ordering Code:
Devices also availab le in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering code.
Connection Diagram Function Table
I = Input
O = Output
H = HIGH Logic Level
L = LOW Logic Level
Note 1: Possibly destructive osc illation may occ ur if the transc eivers are
enabled in both direc t ions at once.
Order Number Package Number Package Description
DM74LS243M M14A 14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 Narrow
DM74LS243N N14A 14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Control Data Port
Inputs Status
G
AB GBA A B
HHOI
L H (Note 1) (Note 1)
H L ISOLATED
LLIO
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DM74LS243
Absolute Maximum Ratings(Note 2)
Note 2: The “Absolute Maximum Ratings” are those values beyond which
the safety of the dev ice cannot be guaranteed. T he device sh ould not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommend ed O peratin g Cond itions” t able w ill defin e the co ndition s
for actual device operation.
Recommended Operating Conditions
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Note 3: All typicals are at VCC = 5V, TA = 25°C.
Note 4: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Supply Voltage 7V
Input Voltage
Any G 7V
A or B 5.5V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range −65°C to +150°C
Symbol Parameter Min Nom Max Units
V
CC
Supply Voltage 4.75 5 5.25 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 24 mA
T
A
Free Air Operating Temperature 0 70 °C
Symbol Parameter Conditions Min
Typ
Max Units
(Note 3)
V
I
Input Clamp Voltage VCC = Min, II = −18 mA −1.5 V
HYS Hysteresis (VT+ − VT−)V
CC
= Min 0.2 0.4 V
(Data Inputs Only)
V
OH
HIGH Level Output Voltage VCC = Min, VIH = Min 2.7
VIL = Max, IOH = −1 mA
VCC = Min, VIH = Min 2.4 3.4 V
VIL = Max, IOH = −3 mA
VCC = Min, VIH = Min 2
VIL = 0.5V, IOH = Max
V
OL
LOW Level Output Voltage VCC = Min IOL = 12 mA 0.4
VIL = Max IOL = Max V
VIH = Min 0.5
I
OZH
Off-State Output Current, VCC = Max VO = 2.7V 40 µA
HIGH Level Voltage Applied VIL = Max
I
OZL
Off-State Output Current, VIH = Min VO = 0.4V −200 µA
LOW Level Voltage Applied
I
I
Input Current at Maximum VCC = Max VI = 5.5V A or B 0.1 mA
Input Voltage VI = 7V Any G 0.1 mA
I
IH
HIGH Level Input Current VCC = Max, VI = 2.7V 20 µA
I
IL
LOW Level Input Current VCC = Max, VI = 0.4V −0.2 mA
I
OS
Short Circuit Output Current VCC = Max (Note 4) −40 −225 mA
I
CC
Supply Current VCC = Max Outputs HIGH 22 38
Outputs Outputs LOW 29 50 mA
OPEN Outputs Disabled 32 54
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