74185

DM54184 NSC | Alldatasheet

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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 con- nections 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 illus- trated in the typical applications. This means that a 6-bit converter is produced in each case. Both devices are cas- cadable to N bits. An overriding enable input is provided on each converter which when taken high inhibits the function, causing all out- puts 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 analo- gous to the algorithm: a. Shift BCD number right one bit and examine each dec- ade. 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 comple- ment code is logically equal to one of the BCD bits; there- fore, these complements can be produced on three lines. As outputs Y6, Y7 and Y8 are not required in the BCD-to-bi- nary conversion, they are utilized to provide these comple- ment codes as specified in the function table when the de- vices are connected as shown. DM74185A BINARY-TO-BCD CONVERTERS The function performed by these 6-bit binary-to-BCD con- verters 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 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 7V Input Voltage 5.5V Output Voltage 7V Operating Free Air Temperature Range 0 §Ct o a70§C Storage Temperature Range b65§Ct o a150§C Note: The ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaran- teed. 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 Parameter Min Nom Max Units VCC Supply Voltage 4.75 5 5.25 V VIH High Level Input Voltage 2 V VIL Low Level Input Voltage 0.8 V VOH High Level Output Voltage 5.5 V IOL Low Level Output Current 12 mA TA Free Air Operating Temperature 0 70 §C ’184 and ’185A Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units(Note 1) VI Input Clamp Voltage V CC e Min, I I eb 12 mA b1.5 V ICEX High Level Output V CC e Min, V O e 5.5V 100 mACurrent V IL e Max, V IH e Min VOL Low Level Output V CC e Min, I OL e Max 0.4 VVoltage V IH e Min, V IL e Max II Input Current @ Max V CC e Max, V I e 5.5V 1m AInput Voltage IIH High Level Input Current V CC e Max, V I e 2.4V 25 mA IIL Low Level Input Current V CC e Max, V I e 0.4V b1m A ICCH Supply Current with V CC e Max 65 95 mAOutputs High ICCL Supply Current with V CC e Max 80 99 mAOutputs Low ’184 and ’185A Switching Characteristics at V CC e 5V and T A e 25§C (See Section 1 for Test Waveforms and Output Load) From (Input) RL1 e 400X,R L2 e 600X Symbol Parameter To (Output) CL e 15 pF (See Test Circuit) Units Min Max tPLH Propagation Delay Time Enable G 35 nsLow to High Level Output to Output tPHL Propagation Delay Time Enable G 35 nsHigh to Low Level Output to Output tPLH Propagation Delay Time Binary Select 35 nsLow to High Level Output to Output tPHL Propagation Delay Time Binary Select 35 nsHigh to Low Level Output to Output Note 1: All typicals are at V CC e 5V, T A e 25§C.

General Description (Continued) DM74184 BCD-to-Binary TABLE I. Package Count and Delay Times for BCD-to-Binary Conversion Input Packages Total Delay Times (ns) (Decades) Required Typ Max 2 2 56 80 3 6 140 200 4 12 196 280 5 19 280 400 6 28 364 520 6-Bit Converter TL/F/6561–2 BCD 9’s Complement Converter TL/F/6561–3 BCD’s 10’s Complement Converter TL/F/6561–4 DM74185A Binary-to-BCD TABLE II. Package Count and Delay Times for Binary-to-BCD Conversion Input Packages Total Delay Times (ns) (Bits) Required Typ Max 4t o6 1 2 5 4 0 7o r8 3 5 0 8 0 9 4 75 120 10 6 100 160 11 7 125 200 12 8 125 200 13 10 150 240 14 12 175 280 15 14 175 280 16 16 200 320 17 19 225 360 18 21 225 360 19 24 250 400 20 27 275 440 6-Bit Converter TL/F/6561–5

Words Binary Select Enable EDCBA G Y 8Y 7Y 6Y 5Y 4Y 3Y 2Y 1 0 1 L L L L L L H HLLLLLL 2 3 L L L L H L H HLLLLLH

45 L L L H L L HHLLLLHL

6 7 L L L H H L H HLLLLH H

89 L L H L L L HHLLLHLL

10 11 L L H L H L H H L L H L L L 1 2 1 3 L L H H L L HHLLHLLH 1 4 1 5 L L H H H L HHLLHLHL 1 6 1 7 L H L L L L HHLLHLHH 1 8 1 9 L H L L H L HHLLHHLL 2 0 2 1 L H L H L L H HLHLLLL 22 23 L H L H H L H H L H L L L H 2 4 2 5 L H H L L L HHLHLLHL 2 6 2 7 L H H L H L HHLHLLHH 2 8 2 9 L H H H L L HHLHLHLL 30 31 L H H H H L H H L H H L L L 3 2 3 3 H L L L L L HHLHHLLH 3 4 3 5 H L L L H L HHLHHLHL 3 6 3 7 H L L H L L HHLHHLHH 38 39 H L L H H L H H L H H H L L 4 0 4 1 H L H L L L H H HLLLLL 4 2 4 3 H L H L H L H H HLLLLH 4 44 5HLHHL L H H H L L L H L 4 6 4 7 H L H H H L HHHL L LHH 48 49 H H L L L L H H H L L H L L 50 51 H H L L H L H H H L H L L L 5 2 5 3 H H L H L L HHHLHLLH 5 4 5 5 H H L H H L HHHLHLHL 5 6 5 7 H H H L L L HHHLHLHH 5 8 5 9 H H H L H L HHHLHHLL 6 0 6 1 H H H H L L HHHH LLLL 6 2 6 3 H H H H H L HHHHL L LH A l l X X X X X H HHHHHHHH

67 L L L H H L L L L H H

89 L L H L L L L L H L L

0 L LLLLL H L H

1 L LLLHL H L L

2 L LLHLL L H H

3 L L L H H L LHL

4 L LHLLL L H H

5 L LHLHL L H L

6 L LHHLL L L H

7 L LHHHL L L L

8 L HLLLL L L H

9 L HLLHL L L L

0 H LLLLL L L L

1 H LLLHL H L L

2 H LLHLL H L L

4 H LHLLL L H H

5 H LHLHL L H L

6 H LHHLL L H L

7 H LHHHL L L H

8 HHLLLL L L H

9 H HLLHL L L L

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. high, the BCD 10’s complement is generated. FIGURE 1. BCD-to-Binary Converter

FIGURE 2. BCD-to-Binary Converter for Six BCD Decades

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 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 2. A critical component is any component of a life systems which, (a) are intended for surgical implant support device or system whose failure to perform can into the body, or (b) support or sustain life, and whose be reasonably expected to cause the failure of the life failure to perform, when properly used in accordance support device or system, or to affect its safety or with instructions for use provided in the labeling, can effectiveness. be reasonably expected to result in a significant injury to the user. National Semiconductor National Semiconductor National Semiconductor National Semiconductor Corporation Europe Hong Kong Ltd. Japan Ltd.

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