DM74LS248 BCD to 7-Segment Decoder with 2 kX Pull-Up Resistors General Description The ’LS248 has active HIGH outputs with internal 2 kX pullup resistors. It has the same electrical characteristics and pin connections as the ’LS48. The only difference is that the ’LS248 will light the top bar (segment a) for numeral 6 and the bottom bar (segment d) for numeral 9. For detailed description and specifications please refer to the ’LS48 data sheet. Connection Diagram Logic Symbol Dual-In-Line Package TL/F/10181 – 2 VCC e Pin 16 GND e Pin 8 TL/F/10181 – 1 Order Number DM74LS248M or DM74LS248N See NS Package Number M16A or N16E Pin Names A0–A3 RBI LT BI/RBO a–g C1995 National Semiconductor Corporation TL/F/10181 Description BCD Inputs Ripple Blanking Input (Active LOW) Lamp Test Input (Active LOW) Blanking Input (Active LOW) or Ripple Blanking Output (Active LOW) Segment Outputs (Active HIGH) RRD-B30M105/Printed in U. S. A. DM74LS248 BCD to 7-Segment Decoder with 2 kX Pull-Up Resistors February 1992 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 Voltage IOL Low Level Output Current TA Free Air Operating Temperature Min Nom Max 4.75 5 5.25 Units V 2 V 0 0.8 V b 0.1 mA 6 mA 70 §C Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions Min VI Input Clamp Voltage VCC e Min, II e b18 mA VOH High Level Output Voltage VCC e Min, IOH e Max, VIL e Max VOL Low Level Output Voltage Typ (Note 1) Max Units b 1.5 V 2.4 VCC e Min, IOL e Max, VIH e Min 0.5 IOL e 3.2 mA, VCC e Min 0.4 0.1 mA V II Input Current @ Max Input Voltage VCC e Max, VI e 7V IIH High Level Input Current VCC e Max, VI e 2.7V 20 mA IIL Low Level Input Current VCC e Max, VI e 0.4V b 0.4 mA IOS Short Circuit Output Current VCC e Max (Note 2) ICC Supply Current VCC e Max IOFF Output High Current Segment Inputs, VO e 0.85V b 0.3 b 2.0 mA 38 mA b 1.3 mA 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. Switching Characteristics VCC e a 5.0V, TA e a 25§ C Symbol RL e 2 kX, CL e 15 pF Parameter Min Units Max tPLH Propagation Delay Time Low to High Level Output 100 ns tPHL Propagation Delay Time High to Low Level Output 100 ns 2 Physical Dimensions inches (millimeters) 16-Lead Small Outline Molded Package (M) Order Number DM74LS248M NS Package Number M16A 3 DM74LS248 BCD to 7-Segment Decoder with 2 kX Pull-Up Resistors Physical Dimensions inches (millimeters) (Continued) 16-Lead Molded Dual-In-Line Package (N) Order Number DM74LS248N NS Package Number N16E 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. National Semiconductor Corporation 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Europe Fax: (a49) 0-180-530 85 86 Email: cnjwge @ tevm2.nsc.com Deutsch Tel: (a49) 0-180-530 85 85 English Tel: (a49) 0-180-532 78 32 Fran3ais Tel: (a49) 0-180-532 93 58 Italiano Tel: (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 81-043-299-2309 Fax: 81-043-299-2408 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. 电子爱好者 网站是一个面向广大电子爱好者 大专院校学生 中小型企业工程 技术人员的电子技术应用 推广专业网站 主要内容有 电子技术应用交流 器件资料 电子设计软件下载 电子技术支持服务 电子产品发布 转让和引进等信息 本资料或软件由＂电子爱好者＂网站收集整理 在使用本资料或软件时 有什么问题 欢迎到 论坛 中发表 我站的热心网友会帮助你的 技术论坛 版权属原作者 电子爱好者 网站内的 ＢＢＳ ｈｔｔｐ：／／ｗｗｗ．ｅｔｕｎｉ．ｃｏｍ／ｂｂｓ／ｉｎｄｅｘ．ａｓｐ 需要更多的电子技术相关资料或软件 欢迎到 电子爱好者 电子爱好者 网站 网站下载 ｈｔｔｐ：／／ｗｗｗ．ｅｔｕｎｉ．ｃｏｍ 技术