MC74F157A QUAD 2-INPUT MULTIPLEXER The MC74F157A is a high-speed quad 2-input multiplexer. Four bits of data from two sources can be selected using the common Select and Enable inputs. The four buffered outputs present the selected data in the true (non-inverted) form. The F157A can also be used to generate any four of the 16 different functions to two variables. • AC Enhanced Version of the F157 QUAD 2-INPUT MULTIPLEXER FAST SHOTTKY TTL CONNECTION DIAGRAM DIP (TOP VIEW) VCC E I0c I1c Zc I0d I1d Zd 16 15 14 13 12 11 10 9 J SUFFIX CERAMIC CASE 620-09 16 1 1 2 3 4 5 6 7 8 S I0a I1a Za I0b I1b Zb GND LOGIC DIAGRAM I0a I1a I0b I1b I0c I1c N SUFFIX PLASTIC CASE 648-08 16 I0d I1d E S 1 D SUFFIX SOIC CASE 751B-03 16 1 ORDERING INFORMATION MC74FXXXJ MC74FXXXN MC74FXXXD Za Zb LOGIC SYMBOL Zd Zc Ceramic Plastic SOIC 1 FUNCTION TABLE S Inputs Output E S I0 I1 Z H X X X L L H X L L L H X H H L L L X L L L H X H H = HIGH Voltage Level; L = LOW Voltage Level; X = Don’t Care 4 Za 7 Zb 12 Zc I1b I0c I1c 9 Zd I0d I1d VCC = PIN 16 GND = PIN 8 FAST AND LS TTL DATA 4-67 E I0a I1a I0b 15 2 3 5 6 14 13 11 10 MC74F157A GUARANTEED OPERATING RANGES Symbol Parameter Min Typ Max Unit VCC Supply Voltage 74 4.5 5.0 5.5 V TA Operating Ambient Temperature Range 74 0 25 70 °C IOH Output Current — High 74 –1.0 mA IOL Output Current — Low 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 74 2.7 74 2.5 Input LOW Current IOS Output Short Circuit Current (Note 2) ICC Power Supply Current Guaranteed Input HIGH Voltage 0.8 V Guaranteed Input LOW Voltage –1.2 V IIN = –18 mA VCC = MIN V IOH = –1.0 mA VCC = 4.75 V 0.5 V IOL = 20 mA VCC = MIN VCC = MAX 3.4 VCC = 4.50 V 0.35 IIL Test Conditions V –60 15 20 µA VIN = 2.7 V 100 µA VIN = 7.0 V –0.6 mA VIN = 0.5 V VCC = MAX –150 mA VOUT = 0 V VCC = MAX 23 mA All Inputs = 4.5 V VCC = MAX NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under guaranteed operating ranges. 2. Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS Symbol Parameter 74F 74F TA = +25°C VCC = +5.0 V CL = 50 pF TA = 0°C to 70°C VCC = 5.0 V ±10% CL = 50 pF Min Max Min Max Unit tPLH Propagation Delay 3.5 10 3.5 11 ns tPHL S to Zn 3.0 7.0 3.0 8.0 tPLH Propagation Delay 3.5 9.5 3.5 11 tPHL E to Zn 2.5 6.5 2.5 7.0 tPLH Propagation Delay 2.0 6.0 2.0 6.5 tPHL In to Zn 2.5 5.5 2.0 7.0 ns ns FUNCTIONAL DESCRIPTION The F157A is a quad 2-input multiplexer. It selects four bits of data from two sources under the control of a common Select input (S). The Enable input (E) is active LOW. When E is HIGH, all of the outputs (Z) are forced LOW regardless of all other inputs. The F157A is the logic implementation of a 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the Select input. The logic equations for the outputs are shown below: Za = E • (I1a • S + I0a • S) Zc = E • (I1c • S + I0c • S) A common use of the F157A is the moving of data from two groups of registers to four common output busses. The particular register from which the data comes is determined by the state of the Select input. A less obvious use is as a function generator. The F157A can generate any four of the 16 different functions of two variables with one variable common. This is useful for implementing highly irregular logic. Zb = E • (I1b • S + I0b • S) Zd = E • (I1d • S + I0d • S) FAST AND LS TTL DATA 4-68