Main MenuBackSearchfairchildsemi.com© 2000 Fairchild Semiconductor Corporation DS006412 www.fairchildsemi.comAugust 1986Revised January 2000DM74LS243 Quadruple Bus TransceiverDM74LS243Quadruple Bus TransceiverGeneral DescriptionThis four data line transceiver is designed for asynchro-nous two-way communications between data buses. It canbe used to drive terminated lines down to 133Ω.Features■ Two-way asynchronous communication between databuses■ PNP inputs reduce DC loading on bus line■ Hysteresis at data inputs improves noise margin Ordering Code:Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.Connection Diagram Function TableI = InputO = OutputH = HIGH Logic LevelL = LOW Logic LevelNote 1: Possibly destructive oscillation may occur if the transceivers areenabled in both directions at once.Order Number Package Number Package DescriptionDM74LS243M M14A 14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 NarrowDM74LS243N N14A 14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 WideControl Data PortInputs StatusG AB GBA A BHHOIL H (Note 1) (Note 1)H L ISOLATEDLLIOwww.fairchildsemi.com 2DM74LS243Absolute Maximum Ratings(Note 2)Note 2: The “Absolute Maximum Ratings” are those values beyond whichthe safety of the device cannot be guaranteed. The device should not beoperated at these limits. The parametric values defined in the ElectricalCharacteristics tables are not guaranteed at the absolute maximum ratings.The “Recommended Operating Conditions” table will define the conditionsfor actual device operation.Recommended Operating ConditionsElectrical Characteristicsover 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 7VInput VoltageAny G 7VA or B 5.5VOperating Free Air Temperature Range 0°C to +70°CStorage Temperature Range −65°C to +150°CSymbol Parameter Min Nom Max UnitsVCCSupply Voltage 4.75 5 5.25 VVIHHIGH Level Input Voltage 2 VVILLOW Level Input Voltage 0.8 VIOHHIGH Level Output Current −15 mAIOLLOW Level Output Current 24 mATAFree Air Operating Temperature 0 70 °CSymbol Parameter Conditions MinTypMax Units(Note 3)VIInput Clamp Voltage VCC = Min, II = −18 mA −1.5 VHYS Hysteresis (VT+ − VT−)VCC = Min 0.2 0.4 V(Data Inputs Only)VOHHIGH Level Output Voltage VCC = Min, VIH = Min 2.7VIL = Max, IOH = −1 mAVCC = Min, VIH = Min 2.4 3.4 VVIL = Max, IOH = −3 mAVCC = Min, VIH = Min 2VIL = 0.5V, IOH = MaxVOLLOW Level Output Voltage VCC = Min IOL = 12 mA 0.4VIL = Max IOL = Max VVIH = Min 0.5IOZHOff-State Output Current, VCC = Max VO = 2.7V 40 µAHIGH Level Voltage Applied VIL = MaxIOZLOff-State Output Current, VIH = Min VO = 0.4V −200 µALOW Level Voltage AppliedIIInput Current at Maximum VCC = Max VI = 5.5V A or B 0.1 mAInput Voltage VI = 7V Any G 0.1 mAIIHHIGH Level Input Current VCC = Max, VI = 2.7V 20 µAIILLOW Level Input Current VCC = Max, VI = 0.4V −0.2 mAIOSShort Circuit Output Current VCC = Max (Note 4) −40 −225 mAICCSupply Current VCC = Max Outputs HIGH 22 38Outputs Outputs LOW 29 50 mAOPEN Outputs Disabled 32 543 www.fairchildsemi.comDM74LS243Switching Characteristicsat VCC = 5V, TA = 25°C Symbol Parameter Conditions Min Max UnitstPLHPropagation Delay Time CL = 45 pF18 nsLOW-to-HIGH Level Output RL = 667ΩtPHLPropagation Delay Time CL = 45 pF18 nsHIGH-to-LOW Level Output RL = 667ΩtPZLOutput Enable Time CL = 45 pF30 nsto LOW Level RL = 667ΩtPZHOutput Enable Time CL = 45 pF23 nsto HIGH Level RL = 667ΩtPLZOutput Disable Time CL = 5 pF25 nsfrom LOW Level RL = 667ΩtPHZOutput Disable Time CL = 5 pF18 nsfrom HIGH Level RL = 667ΩtPLHPropagation Delay Time CL = 150 pF21 nsLOW-to-HIGH Level Output RL = 667ΩtPHLPropagation Delay Time CL = 150 pF22 nsHIGH-to-LOW Level Output RL = 667ΩtPZLOutput Enable Time CL = 150 pF33 nsto LOW Level RL = 667ΩtPZHOutput Enable Time CL = 150 pF26 nsto HIGH Level RL = 667Ωwww.fairchildsemi.com 4DM74LS243Physical Dimensions inches (millimeters) unless otherwise noted14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 NarrowPackage Number M14A5 www.fairchildsemi.comDM74LS243 Quadruple Bus TransceiverPhysical Dimensions inches (millimeters) unless otherwise noted (Continued)14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 WidePackage Number N14AFairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied andFairchild reserves the right at any time without notice to change said circuitry and specifications.LIFE SUPPORT POLICYFAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORTDEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILDSEMICONDUCTOR CORPORATION. As used herein:1. Life support devices or systems are devices or systemswhich, (a) are intended for surgical implant into thebody, or (b) support or sustain life, and (c) whose failureto perform when properly used in accordance withinstructions for use provided in the labeling, can be rea-sonably expected to result in a significant injury to theuser.2. A critical component in any component of a life supportdevice or system whose failure to perform can be rea-sonably expected to cause the failure of the life supportdevice or system, or to affect its safety or
View Full Document
Unlocking...