DM74LS48 BCD to 7-Segment Decoder General Description The ’LS48 translates four lines of BCD (8421) input data into the 7-segment numeral code and provides seven corresponding outputs having pull-up resistors, as opposed to totem pole pull-ups. These outputs can serve as logic signals, with a HIGH output corresponding to a lighted lamp segment, or can provide a 1.3 mA base current to npn lamp driver transistors. Auxiliary inputs provide lamp test, blanking and cascadable zero-suppression functions. The ’LS48 decodes the input data in the pattern indicated in the Truth Table and the segment identification illustration. Connection Diagram Dual-In-Line Package TL/F/10172 – 1 Order Number DM74LS48M or DM74LS48N See NS Package Number M16A or N16E C1995 National Semiconductor Corporation TL/F/10172 RRD-B30M105/Printed in U. S. A. DM74LS48 BCD to 7-Segment Decoder January 1992 Absolute Maximum Ratings (Note) Supply Voltage 7V Input Voltage 7V Operating Free Air Temperature Range DM74LS Storage Temperature Range 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 . 0§ C to a 70§ C b 65§ C to a 150§ C Recommended Operating Conditions Symbol DM74LS48 Parameter VCC Supply Voltage VIH High Level Input Voltage VIL Low Level Input Voltage IOH Units Min Nom Max 4.75 5 5.25 V 2 V 0.8 V High Level Output Current b 50 mA IOL Low Level Output Current 6.0 mA TA Free Air Operating Temperature 70 §C 0 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 Min, IOH e Max, VIL e Max IOFF Output High Current Segment Outputs VCC e Min, VO e 0.85V VOL Low Level Output Voltage VCC e Min, IOL e Max, VIH e Min 0.5 IOL e 2.0 mA, VCC e Min 0.4 VCC e Max, VI e 7V 0.1 2.4 V b 1.3 mA V II Input Current @ Max Input Voltage 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, VO e 0V at BI/RBO (Note 2) b2 mA ICCH Supply Current VCC e Max, VIN e 4.5V 38 mA b 0.3 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 at VCC e 5V and TA e 25§ C Symbol CL e 15 pF Parameter Min Units Max tPLH tPHL Propagation Delay Time An to a–g 100 100 ns tPLH tPHL Propagation Delay Time RBI to a–f 100 100 ns Note: LT e HIGH, A0 –A3 e HIGH. 2 Numerical DesignationsÐResultant Displays TL/F/10172 – 4 Truth Table Decimal Or Function Inputs Outputs LT RBI A3 A2 A1 A0 BI/RBO a b c d e f g 0 (Note 1) 1 (Note 1) 2 3 H H H H H X X X L L L L L L L L L L H H L H L H H H H H H L H H H H H H H H L H H L H H H L H L H L L L L L H H 4 5 6 7 8 H H H H H X X X X X L L L L H H H H H L L L H H L L H L H L H H H H H L H L H H H L L H H H H H H H L H H L H L L H L H H H H L H H H H L H 9 10 11 12 13 H H H H H X X X X X H H H H H L L L H H L H H L L H L H L H H H H H H H L L L H H L L H L H L H L L L H H L H L H L L L H L L H H H H H H H 14 15 BI (Note 2) RBI (Note 3) LT (Note 4) H H X H L X X X L X H H X L X H H X L X H H X L X L H X L X H H L L H L L L L H L L L L H L L L L H H L L L H H L L L H H L L L H H L L L H Note 1: BI/RBO is wired-AND logic serving as blanking input (BI) and/or ripple-blanking output (RBO). The blanking out (BI) must be open or held at a HIGH level when output functions 0 through 15 are desired, and ripple-blanking input (RBI) must be open or at a HIGH level if blanking of a decimal 0 is not desired. X e input may be HIGH or LOW. Note 2: When a LOW level is applied to the blanking input (forced condition) all segment outputs go to a LOW level, regardless of the state of any other input condition. Note 3: When ripple-blanking input (RBI) and inputs A0, A1, A2, and A3 are at LOW level, with the lamp test input at HIGH level, all segment outputs go to a LOW level and the ripple-blanking output (RBO) goes to a LOW level (response condition). Note 4: When the blanking input/ripple-blanking output (BI/RBO) is open or held at a HIGH level, and a LOW level is applied to lamp test input, all segment outputs go to a HIGH level. Logic Symbol TL/F/10172 – 2 VCC e Pin 16 GND e Pin 8 3 Logic Diagram TL/F/10172 – 3 4 Physical Dimensions inches (millimeters) 16-Lead Small Outline Molded Package (M) Order Number DM74LS48M NS Package Number M16A 5 DM74LS48 BCD to 7-Segment Decoder Physical Dimensions inches (millimeters) (Continued) 16-Lead Molded Dual-In-Line Package (N) Order Number DM74LS48N 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. 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