MC54/74F138 1-OF-8 DECODER/ DEMULTIPLEXER The MC54/74F138 is a high speed 1-of-8 Decoder/Demultiplexer. This device is ideally suited for high speed bipolar memory chip select address decoding. The multiple input enables allow parallel expansion to a 1-of-24 decoder using just three F138 devices or to a 1-of-32 decoder using four F138s and one inverter. • Demultiplexing Capability • Multiple Input Enable for Easy Expansion • Active Low Mutually Exclusive Outputs • Input Clamp Diodes Limit High-Speed Termination Effects 1-OF-8 DECODER/ DEMULTIPLEXER FAST SHOTTKY TTL J SUFFIX CERAMIC CASE 620-09 CONNECTION DIAGRAM DIP (TOP VIEW) VCC O0 O1 O2 O3 O4 O5 O6 16 15 14 13 12 11 10 9 16 1 N SUFFIX PLASTIC CASE 648-08 16 1 2 3 4 5 6 7 8 A0 A1 A2 E1 E2 E3 O7 GND 1 D SUFFIX SOIC CASE 751B-03 16 1 ORDERING INFORMATION LOGIC DIAGRAM A2 3 A1 E1 E2 E3 A0 2 1 4 5 VCC = PIN 16 GND = PIN 8 = PIN NUMBERS 6 MC54FXXXJ MC74FXXXN MC74FXXXD Ceramic Plastic SOIC LOGIC SYMBOL 1 2 3 456 1 2 3 A0 A1 A2 O0 O1 O2 O3 O4 O5 O6 O7 9 7 O7 10 O6 12 11 O5 O4 13 O3 O2 15 14 13 12 11 10 9 7 15 14 O1 VCC = PIN 16 GND = PIN 8 O0 FAST AND LS TTL DATA 4-53 MC54/74F138 GUARANTEED OPERATING RANGES Symbol Parameter VCC Supply Voltage TA Operating Ambient Temperature Range Min Typ Max Unit 54, 74 4.5 5.0 5.5 V 54 –55 25 125 °C 74 0 25 70 IOH Output Current — High 54, 74 –1.0 mA IOL Output Current — Low 54, 74 20 mA DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol Parameter VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage VOH Output HIGH Voltage VOL Output LOW Voltage IIH Input HIGH Current Min Typ Max Unit 2.0 54, 74 2.5 74 2.7 Guaranteed Input HIGH Voltage 0.8 V Guaranteed Input LOW Voltage –1.2 V VCC = MIN, IIN = –18 mA V IOH = –1.0 mA VCC = 4.50 V V IOH = –1.0 mA VCC = 4.75 V V IOL = 20 mA VCC = MIN 0.5 IIL Input LOW Current IOS Output Short Circuit Current (Note 2) ICC Power Supply Current –60 Test Conditions V 20 µA VCC = MAX, VIN = 2.7 V 0.1 mA VCC = MAX, VIN = 7.0 V –0.6 mA VCC = MAX, VIN = 0.5 V –150 mA VCC = MAX, VOUT = 0 V 20 mA VCC = MAX NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable device type. 2. Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS Symbol Parameter tPLH Propagation Delay, tPHL Address to Output tPLH Enable to Output tPHL E1 or E2 tPLH Enable to Output tPHL E3 54/74F 54F 74F TA = +25 °C TA = +25°C to +125°C TA = 0°C to 70°C Levels VCC = +5.0 V VCC = 5.0 V ±10% VCC = 5.0 V ±10% of CL = 50 pF CL = 50 pF CL = 50 pF Delay Min Max Min Max Min Max Unit 3 3.0 7.5 3.0 12 3.0 8.5 ns 3.0 8.0 3.0 9.5 3.0 9.0 3.5 7.0 3.5 11 3.5 8.0 3.0 7.0 3.0 8.0 3.0 7.5 4.0 8.0 4.0 12.5 4.0 9.0 3.5 7.5 3.5 8.5 3.5 8.5 2 3 ns ns FUNCTIONAL DESCRIPTION The decoder accepts three binary weighted inputs (AO, A1, A2) and when enabled provides eight mutually exclusive active LOW outputs (O0–O7). The F138 features three Enable inputs, two active LOW (E1, E2) and one active HIGH (E3). All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion of the device to a 1-of-32 (5 lines to 32 lines) decoder with just four F138s and one inverter. The F138 can be used as an 8-output demultiplexer by using one of the active LOW Enable inputs as the data input and the other Enable inputs as strobes. The Enable inputs which are not used must be permanently tied to their appropriate active HIGH or active LOW states. FAST AND LS TTL DATA 4-54 MC54/74F138 FUNCTION TABLE Inputs E1 H X X L L L L L L L L E2 X H X L L L L L L L L E3 X X L H H H H H H H H Outputs A0 A1 A2 O0 O1 O2 O3 O4 O5 O6 O7 X X X L H L H L H L H X X X L L H H L L H H X X X L L L L H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H = HIGH Voltage Level L = LOW Voltage Level X = Don’t Care A0 A1 A2 FO4 A3 A4 H 123 A0 A1 A2 E 123 A0 A1 A2 E 123 A0 A1 A2 E 123 A0 A1 A2 E F138 F138 F138 F138 O0 O1 O2 O3 O4 O5 O6 O7 O0 O1 O2 O3 O4 O5 O6 O7 O0 O1 O2 O3 O4 O5 O6 O7 O0 O1 O2 O3 O4 O5 O6 O7 O31 O0 FAST AND LS TTL DATA 4-55