QUAD 2-INPUT MULTIPLEXER WITH 3-STATE OUTPUTS The LSTTL / MSI SN54 / 74LS257B and the SN54 / 74LS258B are Quad 2-Input Multiplexers with 3-state outputs. Four bits of data from two sources can be selected using a Common Data Select input. The four outputs present the selected data in true (non-inverted) form. The outputs may be switched to a high impedance state with a HIGH on the common Output Enable (EO) Input, allowing the outputs to interface directly with bus oriented systems. It is fabricated with the Schottky barrier diode process for high speed and is completely compatible with all Motorola TTL families. • • • • • • Schottky Process For High Speed Multiplexer Expansion By Tying Outputs Together Non-Inverting 3-State Outputs Input Clamp Diodes Limit High Speed Termination Effects Special Circuitry Ensures Glitch Free Multiplexing ESD > 3500 Volts SN54/74LS257B SN54/74LS258B QUAD 2-INPUT MULTIPLEXER WITH 3-STATE OUTPUTS LOW POWER SCHOTTKY J SUFFIX CERAMIC CASE 620-09 16 1 N SUFFIX PLASTIC CASE 648-08 CONNECTION DIAGRAM DIP (TOP VIEW) 16 1 SN54/74LS257B 16 1 ORDERING INFORMATION SN54LSXXXJ SN74LSXXXN SN74LSXXXD NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package. SN54/74LS258B D SUFFIX SOIC CASE 751B-03 FAST AND LS TTL DATA 5-427 Ceramic Plastic SOIC SN54/74LS257B D SN54/74LS258B LOGIC DIAGRAMS SN54 / 74LS257B SN54 / 74LS258B FAST AND LS TTL DATA 5-428 SN54/74LS257B D SN54/74LS258B FUNCTIONAL DESCRIPTION The LS257B and LS258B are Quad 2-Input Multiplexers with 3-state outputs. They select four bits of data from two sources each under control of a Common Data Select Input. When the Select Input is LOW, the I0 inputs are selected and when Select is HIGH, the I1 inputs are selected. The data on the selected inputs appears at the outputs in true (noninverted) form for the LS257B and in the inverted form for the LS258B. The LS257B and LS258B are 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: LS257B Za = E0 • (I1a • S + I0a • S) Zb = E0 • (I1b • S + I0b • S) Zc = E0 • (I1c • S + I0c • S) Zd = E0 • (I1d • S + I0d • S) When the Output Enable Input (E0) is HIGH, the outputs are forced to a high impedance “off” state. If the outputs are tied together, all but one device must be in the high impedance state to avoid high currents that would exceed the maximum ratings. Designers should ensure that Output Enable signals to 3-state devices whose outputs are tied together are designed so there is no overlap. LS258B Za = E0 • (I1a • S + I0a • S) Zb = E0 • (I1b • S + I0b • S) Zc = E0 • (I1c • S + I0c • S) Zd = E0 • (I1d • S + I0d • S) TRUTH TABLE OUTPUT ENABLE SELECT INPUT DATA INPUTS EO S I0 H L L L L X H H L L X X X L H OUTPUTS LS257B OUTPUTS LS258B I1 Z Z X L H X X (Z) L H L H (Z) H L H L H = HIGH Voltage Level L = LOW Voltage Level X = Don’t Care (Z) = High Impedance (off) 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 – 1.0 – 2.6 mA IOL Output Current — Low 54 74 12 24 mA FAST AND LS TTL DATA 5-429 SN54/74LS257B D SN54/74LS258B DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol VIH Input HIGH Voltage VIL Input LOW Voltage VIK Input Clamp Diode Voltage VOH Output HIGH Voltage VOL Output LOW Voltage IOZH IOZL IIH Min Parameter Typ Max Unit 2.0 54 0.7 74 0.8 – 0.65 – 1.5 Test Conditions V Guaranteed Input HIGH Voltage for All Inputs V Guaranteed Input LOW Voltage for All Inputs V VCC = MIN, IIN = – 18 mA 54 2.4 3.4 V 74 2.4 3.1 V VCC = MIN, IOH = MAX, VIN = VIH or VIL per Truth Table 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 – 20 µA VCC = MAX, VOUT = 0.4 V 20 40 µA VCC = MAX, VIN = 2.7 V 0.1 0.2 mA VCC = MAX, VIN = 7.0 V – 0.4 mA VCC = MAX, VIN = 0.4 V – 130 mA VCC = MAX mA Input HIGH Current Other Inputs S Inputs Other Inputs S Inputs IIL Input LOW Current All Inputs IOS Short Circuit Current (Note 1) – 30 Power Supply Current ICC Total, Output HIGH LS257B LS258B 10 9.0 Total, Output LOW LS257B LS258B 16 14 mA Total, Output 3-State LS257B LS258B 19 16 mA VCC = MAX 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) See SN54LS251 for Waveforms Limits Symbol Parameter Min Typ Max Unit Test Conditions tPLH tPHL Propagation Delay, Data to Output 10 12 13 15 ns Figures 1 & 2 tPLH tPHL Propagation Delay, Select to Output 14 14 21 21 ns Figures 1 & 2 tPZH Output Enable Time to HIGH Level 20 25 ns Figures 4 & 5 tPZL Output Enable Time to LOW Level 20 25 ns Figures 3 & 5 tPLZ Output Disable Time to LOW Level 16 25 ns Figures 3 & 5 tPHZ Output Disable Time from HIGH Level 18 25 ns Figures 4 & 5 FAST AND LS TTL DATA 5-430 CL = 45 pF CL = 45 pF RL = 667 Ω CL = 5.0 pF RL = 667 Ω Case 751B-03 D Suffix 16-Pin Plastic SO-16 -A- "! ! " " ! " # 1 %# ) ! !" $ !" 8 C -T- D M K " ! #! J F ! Case 648-08 N Suffix 16-Pin Plastic R X 45° G " ! ) #! P ! " " 9 -B- ! 16 & ! ! ° ° ° ° ( ( ( ( "! ! " " ! ! ' " " ! ' ! " # & -A- 16 9 1 8 ! ! $ ! B # ) " ! " # ) !" $ !" ) F L C S -T- K H G M J D " Case 620-09 J Suffix 16-Pin Ceramic Dual In-Line -A- ! ! ! ! ° ° ° ° "! ! " 16 " ) " L K M N J G D " $ " $ ! " " ! ! FAST AND LS TTL DATA 5-431 & # ) !" $ !" ) -T $ " " C F & 8 E ! ! ! " " -B1 & 9 * * ! ! ! ! * * ! ° ° ! ° ° Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in different applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. 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Literature Distribution Centers: USA: Motorola Literature Distribution; P.O. Box 20912; Phoenix, Arizona 85036. EUROPE: Motorola Ltd.; European Literature Centre; 88 Tanners Drive, Blakelands, Milton Keynes, MK14 5BP, England. JAPAN: Nippon Motorola Ltd.; 4-32-1, Nishi-Gotanda, Shinagawa-ku, Tokyo 141, Japan. ASIA PACIFIC: Motorola Semiconductors H.K. Ltd.; Silicon Harbour Center, No. 2 Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong. ◊ FAST AND LS TTL DATA 5-432