DM74LS126A Quad TRI-STATEÉ Buffer General Description This device contains four independent gates each of which performs a non-inverting buffer function. The outputs have the TRI-STATE feature. When enabled, the outputs exhibit the low impedance characteristics of a standard LS output with additional drive capability to permit the driving of bus lines without external resistors. When disabled, both the output transistors are turned off presenting a high-impedance state to the bus line. Thus the output will act neither as a significant load nor as a driver. To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the disable time is shorter than the enable time of the outputs. Connection Diagram Dual-In-Line Package TL/F/6388 – 1 Order Number DM74LS126AM or DM74LS126AN See NS Package Number M14A or N14A Function Table YeA Inputs Output A C Y L H X H H L L H Hi-Z H e High Logic Level L e Low Logic Level X e Either Low or High Logic Level Hi-Z e TRI-STATE (Outputs are disabled) TRI-STATEÉ is a registered trademark of National Semiconductor Corporation. C1995 National Semiconductor Corporation TL/F/6388 RRD-B30M105/Printed in U. S. A. DM74LS126A Quad TRI-STATE Buffer September 1991 Absolute Maximum Ratings (Note) Supply Voltage Note: 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. 7V Input Voltage Operating Free Air Temperature Range Storage Temperature Range 7V 0§ C to a 70§ C b 65§ C to a 150§ C Recommended Operating Conditions Symbol Parameter VCC Supply Voltage VIH High Level Input Voltage VIL Low Level Input Voltage IOH High Level Output Current IOL Low Level Output Current TA Free Air Operating Temperature Min Nom Max 4.75 5 5.25 Units V V 0 0.8 V b 2.6 mA 24 mA 70 §C Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions Min Typ (Note 1) Max Units b 1.5 V VI Input Clamp Voltage VCC e Min, II e b18 mA VOH High Level Output Voltage VCC e Min, IOH e Max VIH e Min VOL Low Level Output Voltage VCC e Min, IOL e Max VIL e Max, VIH e Min 0.35 0.5 IOL e 12 mA, VCC e Min 0.25 0.4 II Input Current @ Max Input Voltage IIH IIL IOZH 2.4 V V VCC e Max, VI e 7V 0.1 mA High Level Input Current VCC e Max, VI e 2.7V 20 mA Low Level Input Current VCC e Max, VI e 0.4V b 0.4 mA Off-State Output Current with High Level Output Voltage Applied VCC e Max, VO e 2.4V VIH e Min, VIL e Max 20 mA Off-State Output Current with Low Level Output Voltage Applied VCC e Max, VO e 0.4V VIH e Min, VIL e Max b 20 mA IOS Short Circuit Output Current VCC e Max (Note 2) b 100 mA ICC Supply Current VCC e Max 22 mA IOZL b 20 12 Note 1: All typicals are at VCC e 5V, TA e 25§ C. Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second. 2 Switching Characteristics: DM74LS RL e 667X Symbol Parameter CL e 50 pF Min Max CL e 150 pF Min Units Max tPLH Propagation Delay Time Low to High Level Output 15 21 ns tPHL Propagation Delay Time High to Low Level Output 18 22 ns tPZH Output Enable Time to High Level Output 30 36 ns tPZL Output Enable Time to Low Level Output 30 42 ns tPHZ Output Disable Time from High Level Output (Note 1) 25 ns tPLZ Output Disable Time from Low Level Output (Note 1) 25 ns Note 1: CL e 5pF. Physical Dimensions inches (millimeters) 14-Lead Small Outline Molded Package (M) Order Number DM74LS126AM NS Package Number M14A 3 DM74LS126A Quad TRI-STATE Buffer Physical Dimensions inches (millimeters) (Continued) 14-Lead Molded Dual-In-Line Package (N) Order Number DM74LS126AN NS Package Number N14A LIFE SUPPORT POLICY NATIONAL’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 NATIONAL 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 whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 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