SN54/74LS623 OCTAL BUS TRANSCEIVER WITH 3-STATE OUTPUT The SN54 / 74LS623 series is an octal bus transceiver designed for asynchronous two-way communication between data buses. Control function implementation allows maximum timing flexibility. Enable inputs may be used to disable the device so that buses are effectively isolated. Depending on the Logic Levels at the enable inputs, Data transmission is allowed from the A bus to the B bus or from the B bus to the A bus. The dual-enable configuration gives the LS623 the capability to store data by simultaneous enabling of GBA and GAB. Each output reinforces its input in this transceiver configuration. Thus, when both control inputs are enabled all other data sources to the two sets of bus lines (16 in all) will remain at their last states. OCTAL BUS TRANSCEIVER WITH 3-STATE OUTPUT LOW POWER SCHOTTKY J SUFFIX CERAMIC CASE 732-03 20 1 CONNECTION DIAGRAM (TOP VIEW) ENABLE VCC GBA B1 20 19 18 B2 B3 B4 B5 B6 B7 B8 17 16 15 14 13 12 11 N SUFFIX PLASTIC CASE 738-03 20 1 DW SUFFIX SOIC CASE 751D-03 20 1 2 ENABLE A1 GAB 3 A2 4 A3 5 A4 6 A5 7 A6 8 A7 9 A8 1 10 GND ORDERING INFORMATION BLOCK DIAGRAM SN54LSXXXJ Ceramic SN74LSXXXN Plastic SN74LSXXXDW SOIC 1/4 LS623 GBA GAB A1 B1 FUNCTION TABLE A2 ENABLE INPUTS B2 TO OTHER SIX TRANSCEIVERS OPERATION GBA GAB LS623 L L B data to A bus H H A data to B bus H L Isolation L H B data to A bus, A data to B bus H = HIGH Level, L = LOW Level, X = Irrelevant FAST AND LS TTL DATA 5-1 SN54/74LS623 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 IOH Output Current — High 54, 74 – 3.0 mA 54 74 –12 –15 mA 54 74 12 24 mA IOL Output Current — Low DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol Min Parameter VIH Input HIGH Voltage VIL Input LOW Voltage VT+–VT– Hysteresis VIK Input Clamp Diode Voltage VOH Output HIGH Voltage VOL Output LOW Voltage IOZH IOZL Typ Max 2.0 54 0.5 74 0.6 0.2 0.4 – 0.65 54, 74 2.4 54, 74 2.0 – 1.5 3.4 Test Conditions V Guaranteed Input HIGH Voltage for All Inputs V Guaranteed Input LOW Voltage for All Inputs V VCC = MIN V VCC = MIN, IIN = – 18 mA V VCC = MIN, IOH = ± 3.0 mA V VCC = MIN, IOH = MAX 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 Output Off Current HIGH 20 µA VCC = MAX, VOUT = 2.7 V Output Off Current LOW – 400 µA VCC = MAX, VOUT = 4.0 V A, or B, GBA or GAB 20 µA VCC = MAX, VIN = 2.7 V GAB or GAB 0.1 mA VCC = MAX, VIN = 7.0 V IIH Input HIGH Current IIL Input LOW Current IOS Short Circuit Current (Note 1) A or B ICC Unit – 40 0.1 mA VCC = MAX, VIN = 5.5 V – 0.4 mA VCC = MAX, VIN = 0.4 V – 225 mA VCC = MAX mA VCC = MAX Power Supply Current Total Output HIGH 70 Total Output LOW 90 Total at HIGH Z 95 Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. FAST AND LS TTL DATA 5-2 SN54/74LS623 AC CHARACTERISTICS (TA = 25°C, VCC = 5.0 V) Limits Typ Max Unit tPLH tPHL Symbol Propagation Delay A to B Parameter 8.0 11 15 15 ns tPLH tPHL Propagation Delay B to A 8.0 11 15 15 ns tPZL tPZH Output Enable Time GBA to A 31 26 40 40 ns tPZL tPZH Output Enable Time GAB to B 31 26 40 40 ns tPLZ tPHZ Output Disable Time GBA to A 15 15 25 25 ns tPLZ tPHZ Output Disable Time GAB to B 15 15 25 25 ns Min FAST AND LS TTL DATA 5-3 Test Conditions CL = 45 pF, RL = 667 Ω CL = 5.0 pF