SN54/74LS640 SN54/74LS641 SN54/74LS642 SN54/74LS645 OCTAL BUS TRANSCEIVERS These octal bus transceivers are designed for asynchronous two-way communication between data buses. Control function implementation minimizes external timing requirements. These circuits allow data transmission from the A bus to B or from the B bus to A bus depending upon the logic level of the direction control (DIR) input. Enable input (G) can disable the device so that the buses are effectively isolated. OCTAL BUS TRANSCEIVERS LOW POWER SCHOTTKY DEVICE LS640 LS641 LS642 LS645 OUTPUT 3-State Open-Collector Open-Collector 3-State LOGIC Inverting True Inverting True FUNCTION TABLE CONTROL INPUTS J SUFFIX CERAMIC CASE 732-03 20 OPERATION 1 G DIR LS640 LS642 LS641 LS645 L L B data to A bus B data to A bus L H A data to B bus A data to B bus H X Isolation Isolation N SUFFIX PLASTIC CASE 738-03 20 1 H = HIGH Level, L = LOW Level, X = Irrelevant DW SUFFIX SOIC CASE 751D-03 20 1 ORDERING INFORMATION SN54LSXXXJ Ceramic SN74LSXXXN Plastic SN74LSXXXDW SOIC CONNECTION DIAGRAMS DIP (TOP VIEW) ENABLE VCC G B1 20 19 18 B2 B3 B4 B5 B6 B7 B8 17 16 15 14 13 12 11 1 DIR 4 A3 5 A4 6 A5 7 A6 8 A7 9 A8 10 GND 2 A1 3 A2 ENABLE VCC G B1 20 19 18 B2 B3 B4 B5 B6 B7 B8 17 16 15 14 13 12 11 1 DIR 4 A3 5 A4 6 A5 7 A6 8 A7 9 A8 10 GND 2 A1 3 A2 SN54 / 74LS640 SN54 / 74LS642 SN54 / 74LS641 SN54 / 74LS645 FAST AND LS TTL DATA 5-1 SN54/74LS640 • SN54/74LS645 GUARANTEED OPERATING RANGES Min Typ Max Unit VCC Symbol Supply Voltage 54 74 4.5 4.75 5.0 5.0 5.5 5.25 V TA Operating Ambient Temperature Range 54 74 – 55 0 25 25 125 70 °C IOH Output p Current — High g 54, 74 – 3.0 mA 54 74 –12 –15 mA 54 74 12 24 mA IOL Parameter Output Current — Low DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol S b l Parameter P VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage VOH Min Typ Max 2.0 Output HIGH Voltage 54 0.5 74 0.6 – 0.65 54, 74 2.4 54, 74 2.0 – 1.5 3.4 Unit U i Test Conditions T C di i V Guaranteed Input HIGH Voltage for All Inputs V Guaranteed Input LOW Voltage for All Inputs V V VCC = MIN, IIN = – 18 mA VCC = MIN, IOH = 3.0 mA V VCC = MIN, IOH = MAX 54, 74 0.25 0.4 V IOL = 12 mA 74 0.35 0.5 V IOL = 24 mA VCC = MAX, VOUT = 2.7 V VCC = MAX, VOUT = 0.4 V VCC = VCC MIN, VIN = VIL or VIH per Truth Table VOL Output LOW Voltage IOZH IOZL Output Off Current HIGH 20 µA Output Off Current LOW – 400 µA A or B, DIR or G 20 µA DIR or G 0.1 mA A or B 0.1 mA – 0.4 mA VCC = MAX, VIN = 5.5 V VCC = MAX, VIN = 0.4 V – 225 mA VCC = MAX mA VCC = MAX IIH IIL IOS ICC Input I p HIGH Current C Input LOW Current Output Short Circuit Current (Note 1) – 40 Power Supply Current Total Output HIGH 70 Total, Output LOW 90 Total at HIGH Z 95 VCC = MAX, VIN = 2.7 V VCC = MAX, VIN = 7.0 V Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS (TA = 25°C, VCC = 5.0 V) Limits LS640 Symbol S b l Parameter P LS645 Typ Max Typ Max Unit U i tPLH tPHL Propagation Delay A to B 6.0 8.0 10 15 8.0 11 15 15 ns tPLH tPHL Propagation Delay B to A 6.0 8.0 10 15 8.0 11 15 15 ns tPZL tPZH Output Enable Time G, DIR to A 31 23 40 40 31 26 40 40 ns tPZL tPZH Output Enable Time G, DIR to B 31 23 40 40 31 26 40 40 ns tPLZ tPHZ Output Disable Time G, DIR to A 15 15 25 25 15 15 25 25 ns tPLZ tPHZ Output Disable Time G, DIR to B 15 15 25 25 15 15 25 25 ns Min Min FAST AND LS TTL DATA 5-2 Test Conditions T C di i CL = 45 pF, F RL = 667 Ω 5 0 pF CL = 5.0 SN54/74LS641 • SN54/74LS642 GUARANTEED OPERATING RANGES Symbol Parameter Min Typ Max Unit VCC Supply Voltage 54 74 4.5 4.75 5.0 5.0 5.5 5.25 V TA Operating Ambient Temperature Range 54 74 – 55 0 25 25 125 70 °C VOH Output Current — High 54, 74 5.5 V IOL Output Current — Low 54 74 12 24 mA DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits S b l Symbol VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage IOH Output HIGH Current VOL Output LOW Voltage IIH Input HIGH Current IIL Input LOW Current ICC Min P Parameter Typ Max Guaranteed Input HIGH Voltage for All Inputs V Guaranteed Input p LOW Voltage g for All Inputs – 1.5 V VCC = MIN, IIN = – 18 mA 100 µA VCC = MIN, VOH = MAX 54 0.5 74 0.6 – 0.65 T Test C Conditions di i V 2.0 54, 74 U i Unit VCC = VCC MIN, VIN = VIL or VIH per Truth Table 54, 74 0.25 0.4 V IOL = 12 mA 74 0.35 0.5 V IOL = 24 mA 20 µA VCC = MAX, VIN = 2.7 V –0.1 mA VCC = MAX, VIN = 7.0 V – 0.4 mA VCC = MAX, VIN = 0.4 V mA VCC = MAX Typ Max Unit U i Power Supply Current Total, Output HIGH 70 Total, Output LOW 90 Total at HIGH Z 95 AC CHARACTERISTICS (TA = 25°C, VCC = 5.0 V) Limits LS641 Symbol S b l Parameter P Min LS642 Typ Max Min tPLH tPHL Propagation Delay, A to B 17 16 25 25 19 14 25 25 ns tPLH tPHL Propagation Delay, B to A 17 16 25 25 19 14 25 25 ns tPLH tPHL Propagation Delay, G, DIR to A 23 34 40 50 26 43 40 60 ns tPLH tPHL Propagation Delay, G, DIR to B 25 37 40 50 28 39 40 60 ns FAST AND LS TTL DATA 5-3 Test C Conditions di i T F, CL = 45 p pF, RL = 667 Ω