74185

DM74184 DM74185A BCD-to-Binary and Binary-to-BCD Converters June 1989 DM74184 DM74185A BCD-to-Binary and Binary-to-BCD Converters General Description These monolithic converters are derived from the 256-bit read only memories DM5488 and DM7488 Emitter connections are made to provide direct read-out of converted codes at outputs Y8 through Y1 as shown in the function tables These converters demonstrate the versatility of a read only memory in that an unlimited number of reference tables or conversion tables may be built into a system Both of these converters comprehend that the least significant bits (LSB) of the binary and BCD codes are logically equal and in each case the LSB bypasses the converter as illustrated in the typical applications This means that a 6-bit converter is produced in each case Both devices are cascadable to N bits An overriding enable input is provided on each converter which when taken high inhibits the function causing all outputs to go high For this reason and to minimize power consumption unused outputs Y7 and Y8 of the 185A and all ‘‘don’t care’’ conditions of the 184 are programmed high The outputs are of the open-collector type DM74184 BCD-TO-BINARY CONVERTERS The 6-bit BCD-to-binary function of the DM74184 is analogous to the algorithm a Shift BCD number right one bit and examine each decade Subtract three from each 4-bit decade containing a binary value greater than seven b Shift right examine and correct after each shift until the least significant decade contains a number smaller than eight and all other converted decades contain zeros In addition to BCD-to-binary conversion the DM74184 is programmed to generate BCD 9’s complement or BCD 10’s complement Again in each case one bit of the complement code is logically equal to one of the BCD bits therefore these complements can be produced on three lines As outputs Y6 Y7 and Y8 are not required in the BCD-to-binary conversion they are utilized to provide these complement codes as specified in the function table when the devices are connected as shown DM74185A BINARY-TO-BCD CONVERTERS The function performed by these 6-bit binary-to-BCD converters is analogous to the algorithm a Examine the three most significant bits If the sum is greater than four add three and shift left one bit b Examine each BCD decade If the sum is greater than four add three and shift left one bit c Repeat step b until the least-significant binary bit is in the least-significant BCD location (Continued) Connection Diagram TL F 6561 – 1 Order Number DM74184N or DM74185AN See NS Package Number N16E C1995 National Semiconductor Corporation TL F 6561 RRD-B30M105 Printed in U S A Absolute Maximum Ratings (Note) If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage Input Voltage Output Voltage Operating Free Air Temperature Range Storage Temperature Range 7V 5 5V 7V 0 C to a 70 C b 65 C to a 150 C 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 Recommended Operating Conditions Symbol VCC VIH VIL VOH IOL TA Parameter Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Current Free Air Operating Temperature 0 Min 4 75 2 08 55 12 70 Nom 5 Max 5 25 Units V V V V mA C ’184 and ’185A Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol VI ICEX VOL II IIH IIL ICCH ICCL Parameter Input Clamp Voltage High Level Output Current Low Level Output Voltage Input Current Input Voltage Max Conditions VCC e Min II e b12 mA VCC e Min VO e 5 5V VIL e Max VIH e Min VCC e Min IOL e Max VIH e Min VIL e Max VCC e Max VI e 5 5V VCC e Max VI e 2 4V VCC e Max VI e 0 4V VCC e Max VCC e Max 65 80 Min Typ (Note 1) Max b1 5 Units V mA V mA mA mA mA mA 100 04 1 25 b1 High Level Input Current Low Level Input Current Supply Current with Outputs High Supply Current with Outputs Low 95 99 ’184 and ’185A Switching Characteristics at VCC e 5V and TA e 25 C (See Section 1 for Test Waveforms and Output Load) From (Input) To (Output) Enable G to Output Enable G to Output Binary Select to Output Binary Select to Output RL1 e 400X RL2 e 600X CL e 15 pF (See Test Circuit) Min tPLH tPHL tPLH tPHL Propagation Delay Time Low to High Level Output Propagation Delay Time High to Low Level Output Propagation Delay Time Low to High Level Output Propagation Delay Time High to Low Level Output Max 35 35 35 35 ns ns ns ns Symbol Parameter Units Note 1 All typicals are at VCC e 5V TA e 25 C 2 General Description (Continued) DM74184 BCD-to-Binary TABLE I Package Count and Delay Times for BCD-to-Binary Conversion Input (Decades) 2 3 4 5 6 6-Bit Converter Packages Required 2 6 12 19 28 Total Delay Times (ns) Typ 56 140 196 280 364 BCD 9’s Complement Converter Max 80 200 280 400 520 BCD’s 10’s Complement Converter TL F 6561–2 TL F 6561 – 3 TL F 6561 – 4 DM74185A Binary-to-BCD TABLE II Package Count and Delay Times for Binary-to-BCD Conversion Input (Bits) 4 to 6 7 or 8 9 10 11 12 13 14 15 16 17 18 19 20 Packages Required 1 3 4 6 7 8 10 12 14 16 19 21 24 27 Total Delay Times (ns) Typ 25 50 75 100 125 125 150 175 175 200 225 225 250 275 Max 40 80 120 160 200 200 240 280 280 320 360 360 400 440 6-Bit Converter TL F 6561 – 5 3 Function Tables Binary Words E 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 All 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 L L L L L L L L L L L L L L L L H H H H H H H H H H H H H H H H X Inputs Binary Select D C B L L L L L L L L H H H H H H H H L L L L L L L L H H H H H H H H X L L L L H H H H L L L L H H H H L L L L H H H H L L L L H H H H X L L H H L L H H L L H H L L H H L L H H L L H H L L H H L L H H X A L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H X Enable G L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L H Y8 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H Y7 H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H H Y6 L L L L L L L L L L L L L L L L L L L L H H H H H H H H H H H H H Outputs Y5 L L L L L L L L L L H H H H H H H H H H L L L L L L L L L L H H H Y4 L L L L L H H H H H L L L L L H H H H H L L L L L H H H H H L L H Y3 L L L L H L L L L H L L L L H L L L L H L L L L H L L L L H L L H Y2 L L H H L L L H H L L L H H L L L H H L L L H H L L L H H L L L H Y1 L H L H L L H L H L L H L H L L H L H L L H L H L L H L H L L H H 4 Function Tables (Continued) BCD-to-Binary Converter BCD Words 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Any 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 L L L L L L L L L L H H H H H H H H H H Inputs (See Note A) Outputs (See Note B) BCD 9’s or BCD 10’s Complement Converter BCD Word E 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 Any L L L L L L L L L L H H H H H H H H H H X L H L H L H L H L H L H L H L H L H L H H Inputs (See Note C) D L L L L L L L L H H L L L L L L L L H H X C L L L L H H H H L L L L L L H H H H L L X B L L H H L L H H L L L L H H L L H H L L X A L H L H L H L H L H L H L H L H L H L H X G L L L L L L L L L L L L L L L L L L L L H Outputs (See Note D) Y8 H H L L L L L L L L L H H L L L L L L L H Y7 L L H H H H L L L L L L L H H H H L L L H Y6 H L H L H L H L H L L L L H H L L H H L H E D C B A G Y5 Y4 Y3 Y2 Y1 L L L L L H H H H H L L L L L H H H H H L L L L H L L L L H L L L L H L L L L H L L H H L L L H H L L L H H L L L H H L L H L H L L H L H L L H L H L L H L H L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L L H H H H H L L L L L L L L H H H H H H H H L L L L H L L L L H H H H L L L L H H H H L L L L H L L H H L L H H L L H H L L H H L L H H H XXXXXH H e High Level L e Low Level X e Don’t Care Note A Input Conditions other than those shown produce highs at outputs Y1 through Y5 Note B Output Y6 Y7 and Y8 are not used for BCD-to-Binary conversion Note C Input conditions other than those shown produce highs at outputs Y6 Y7 and Y8 Note D Outputs Y1 through Y5 are not used for BCD 9’s or BCD 10’s complement conversion When these devices are used as complement converters input E is used as a mode control With this input low the BCD 9’s complement is generated when it is high the BCD 10’s complement is generated Test Circuit Typical Applications TL F 6561 – 6 CL includes probe and jig capacitance TL F 6561 – 7 FIGURE 1 BCD-to-Binary Converter for Two BCD Decades MSD Most significant decade LSD Least significant decade Each rectangle represents a DM74184 5 Typical Applications (Continued) TL F 6561 – 9 FIGURE 2 BCD-to-Binary Converter for Six BCD Decades MSD Most significant decade LSD Least significant decade Each rectangle represents a DM74184 6 Typical Applications (Continued) TL F 6561 – 10 FIGURE 4 6-Bit Binary-to-BCD Converter MSD Most significant decade LSD Least significant decade Note A Each rectangle represents a DM74185A Note B All unused E inputs are grounded TL F 6561 – 8 FIGURE 3 BCD-to-Binary Converter for Three BCD Decades MSD Most significant decade LSD Least significant decade Each rectangle represents a DM74184 TL F 6561 – 11 TL F 6561 – 12 FIGURE 5 8-Bit Binary-to-BCD Converter MSD Most significant decade LSD Least significant decade Note A Each rectangle represents a DM74185A Note B All unused E inputs are grounded MSD LSD FIGURE 6 9-Bit Binary-to-BCD Converter Most significant decade Least significant decade Note A Each rectangle represents a DM74185A Note B All unused E inputs are grounded 7 Typical Applications (Continued) TL F 6561–13 FIGURE 7 12-Bit Binary-to-BCD Converter (See Note B) TL F 6561 – 14 FIGURE 8 16-Bit Binary-to-BCD Converter (See Note B) MSD LSD Most significant decade Least significant decade Note A Each rectangle represents a DM74185A Note B All unused E inputs are grounded 8 9 DM74184 DM74185A BCD-to-Binary and Binary-to-BCD Converters Physical Dimensions inches (millimeters) 16-Lead Molded Dual-In-Line Package (N) Order Number DM74184N or DM74185AN 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 Fran ais 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