74LS251

DM74LS251 FAIRCHILD | Alldatasheet

Document overview

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Technical content

Features

■ 3-STATE version of DM74LS151 ■ Interface directly with system bus ■ Perform parallel-to-serial conversion ■ Permit multiplexing from N-lines to one line ■ Complementary outputs provide true and inverted data ■ Maximum number of common outputs: 129 ■ Typical propagation delay time (D to Y): 17 ns ■ Typical power dissipation: 35 mW Ordering Code: Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table H = HIGH Logic Level L = LOW Logic Level X = Don't Care Z = High Impedance (OFF) D0, D1…D7 = The level of the respective D input Order Number Package Number Package Description DM74LS251M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow DM74LS251N N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Inputs Outputs Select Strobe YWCBA S XXX H Z Z LLL L D 0 D 0 LLH L D 1 D 1 LHL L D 2D 2 LHH L D 3D 3 HLL L D 4D 4 HLH L D 5D 5 HHL L D 6D 6 HHH L D 7D 7

www.fairchildsemi.com 2 DM74LS251 Logic Diagram

3 www.fairchildsemi.com DM74LS251 Absolute Maximum Ratings(Note 1) Note 1: The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the “Electrical Characteristics” table are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. Recommended Operating Conditions

Electrical Characteristics

over recommended operating free air temperature range (unless otherwise noted) Note 2: All typicals are at VCC = 5V, TA = 25°C. Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second. Note 4: ICC1 is measured with the outputs open, STROBE grounded, and all other inputs at 4.5V. Note 5: ICC2 is measured with the outputs open and all inputs at 4.5V. Supply Voltage 7V Input Voltage 7V Operating Free Air Temperature Range 0°C to +70°C Storage Temperature Range −65°C to +150°C Symbol Parameter Min Nom Max Units V CC Supply Voltage 4.75 5 5.25 V VIH HIGH Level Input Voltage 2 V VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −2.6 mA IOL LOW Level Output Current 24 mA TA Free Air Operating Temperature 0 70 °C Symbol Parameter Conditions Min Typ Max Units (Note 2) VI Input Clamp Voltage V CC = Min, II = −18 mA −1.5 V VOH HIGH Level V CC = Min, IOH = Max 2.4 3.1 V Output Voltage V IL = Max, VIH = Min VOL LOW Level V CC = Min, IOL = Max 0.35 0.5 Output Voltage V IL = Max, VIH = Min V IOL = 12 mA, VCC = Min 0.25 0.4 II Input Current @ Max Input Voltage VCC = Max, VI = 7V 0.1 mA IIH HIGH Level Input Current V CC = Max, VI = 2.7V 20 µA IIL LOW Level Input Current V CC = Max, VI = 0.4V −0.4 mA IOZH Off-State Output Current with V CC = Max, VO = 2.7V 20 µA HIGH Level Output Voltage Applied VIH = Min, VIL = Max IOZL Off-State Output Current with V CC = Max, VO = 0.4V −20 µA LOW Level Output Voltage Applied VIH = Min, VIL = Max IOS Short Circuit Output Current V CC = Max (Note 3) −20 −100 mA ICC1 Supply Current V CC = Max (Note 4) 6.1 10 mA ICC2 Supply Current V CC = Max (Note 5) 7.1 12 mA

www.fairchildsemi.com 4 DM74LS251 Switching Characteristics at VCC = 5V and TA = 25°C Note 6: C L = 5 pF From (Input) R L = 667Ω Symbol Parameter to (Output) C L = 45 pF C L = 150 pF Units Min Max Min Max tPLH Propagation Delay Time A, B, C 45 53 ns LOW-to-HIGH Level Output (4 Levels) to Y tPHL Propagation Delay Time A, B, C 45 53 ns HIGH-to-LOW Level Output (4 Levels) to Y tPLH Propagation Delay Time A, B, C 33 38 ns LOW-to-HIGH Level Output (3 Levels) to W tPHL Propagation Delay Time A, B, C 33 42 ns HIGH-to-LOW Level Output (3 Levels) to W tPLH Propagation Delay Time D to Y 28 35 ns LOW-to-HIGH Level Output tPHL Propagation Delay Time D to Y 28 38 ns HIGH-to-LOW Level Output tPLH Propagation Delay Time D to W 15 25 ns LOW-to-HIGH Level Output tPHL Propagation Delay Time D to W 15 25 ns HIGH-to-LOW Level Output tPZH Output Enable Time to Strobe to Y 45 60 ns HIGH Level Output tPZL Output Enable Time to Strobe to Y 40 51 ns LOW Level Output tPHZ Output Disable Time from Strobe to Y 45 ns HIGH Level Output (Note 6) tPLZ Output Disable Time from Strobe to Y 25 ns LOW Level Output (Note 6) tPZH Output Enable Time to Strobe to W 27 40 ns HIGH Level Output tPZL Output Enable Time to Strobe to W 40 47 ns LOW Level Output tPHZ Output Disable Time from Strobe to W 55 ns HIGH Level Output (Note 6) tPLZ Output Disable Time from Strobe to W 25 ns LOW Level Output (Note 6)

5 www.fairchildsemi.com DM74LS251 Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow Package Number M16A

www.fairchildsemi.com 6 DM74LS251 3-STATE 1-of-8 Line Data Selector/Multiplexer Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Package Number N16E Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be rea- sonably expected to result in a significant injury to the user. 2. A critical component in any component of a life support device or system whose failure to perform can be rea- sonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com