DM8898/DM8899 TRI-STATEÉ BCD to Binary/Binary to BCD Converters General Description These circuits are the TRI-STATE versions of the popular BCD to binary and binary to BCD converters, DM74184 and DM74185A respectively. They are derived from the 256-bit ROM, DM8598. Emitter connections are made to provide direct read out of converted codes at outputs Y8 through Y1, as shown in the truth tables. Both converters comprehend the fact that the least significant bits (LSB) of the binary and BCD codes are logically equal, and in each case the LSB bypasses the converter. Thus a 6-bit converter is produced in each case, and both devices are cascadable. An overriding enable input is provided on each converter which, when taken high, inhibits the function, causing all outputs to go into the high-impedance state. 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. DM8898 BCD-TO-BINARY CONVERTERS The 6-bit BCD-to-binary function of the DM8898 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 DM8898 is programmed to generate BCD 9’s complement or BCD 10’s complement. 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. DM8899A 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. Features Y Y TRI-STATE versions of DM74184, DM74185A Typical propagation delay 30 ns Connection Diagram Dual-In-Line Package TL/F/6593 – 1 Order Number DM8898N or DM8899N See NS Package Number N16A TRI-STATEÉ is a registered trademark of National Semiconductor Corporation. C1995 National Semiconductor Corporation TL/F/6593 RRD-B30M105/Printed in U. S. A. DM8898/DM8899 TRI-STATE BCD to Binary/Binary to BCD Converters January 1987 Absolute Maximum Ratings (Note) 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. If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Supply Voltage Input Voltage Operating Free Air Temperature Range DM88 7V 5.5V 0§ C to a 70§ C b 65§ C to a 150§ C Storage Temperature Range Recommended Operating Conditions Symbol DM8898 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 2 V 0.8 V b 5.2 mA 12 mA 70 §C 0 DM8898 Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions VI Input Clamp Voltage VCC e Min, II e b12 mA VOH High Level Output Voltage VCC e Min, IOH e Max VIL e Max, VIH e Min VOL Low Level Output Voltage VCC e Min, IOL e Max VIH e Min, VIL e Max II Input Current Input Voltage VCC e Max, VI e 5.5V IIH High Level Input Current IIL Low Level Input Current IOZH IOZL @ Max Min Typ (Note 1) Max Units b 1.5 V 2.4 V 0.4 V 1 mA VCC e Max, VI e 2.4V VCC e Max, VI e 0.4V 40 mA b 1.6 mA Off-State Output Current with High Level Output Voltage Applied VCC e Max, VO e 2.4V VIH e Min, VIL e Max 40 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 40 mA IOS Short Circuit Output Current VCC e Max (Note 2) ICC Supply Current VCC e Max b 20 70 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. 2 b 70 mA 99 mA DM8898 Switching Characteristics at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load) RL e 400X Symbol Parameter CL e 5 pF Min CL e 50 pF Max Min Units Max tPLH Propagation Delay Time Low to High Level Output 50 ns tPHL Propagation Delay Time High to Low Level Output 50 ns tPZH Output Enable Time to High Level Output 25 ns tPZL Output Enable Time to Low Level Output 40 ns tPHZ Output Disable Time from High Level Output 20 ns tPLZ Output Disable Time from Low Level Output 36 ns Recommended Operating Conditions Symbol DM8899 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 5.0 5.25 2 0 3 Units V V 0.8 V b 5.2 mA 12 mA 70 §C DM8899 Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol Parameter Conditions Typ (Note 1) Min Max Units b 1.5 V VI Input Clamp Voltage VOH High Level Output Voltage VCC e Min, II e b12 mA VCC e Min, IOH e Max VIL e Max, VIH e Min VOL Low Level Output Voltage VCC e Min, IOL e Max VIH e Min, VIL e Max 0.4 V II Input Current @ Max Input Voltage VCC e Max, VI e 5.5V 1 mA IIH High Level Input Current VCC e Max, VI e 2.4V 40 mA IIL Low Level Input Current VCC e Max, VI e 0.4V b 1.6 mA IOZH Off-State Output Current with High Level Output Voltage Applied VCC e Max, VO e 2.4V VIH e Min, VIL e Max 40 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 40 mA IOZL IOS Short Circuit Output Current VCC e Max (Note 2) ICC Supply Current VCC e Max 2.4 V b 20 70 b 70 mA 99 mA DM8899 Switching Characteristics at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load) RL e 400X Symbol Parameter CL e 5 pF Min CL e 50 pF Max Min Units Max tPLH Propagation Delay Time Low to High Level Output 50 ns tPHL Propagation Delay Time High to Low Level Output 50 ns tPZH Output Enable Time to High Level Output 25 ns tPZL Output Enable Time to Low Level Output 40 ns tPHZ Output Disable Time from High Level Output 20 ns tPLZ Output Disable Time from Low Level Output 36 ns 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. 4 Function Tables BCD-to-Binary Converter Inputs (See Note A) BCD Words BCD 9’s or BCD 10’s Complement Converter Outputs (See Note B) Inputs (See Note C) BCD Word Outputs (See Note D) E² D C B A G Y8 Y7 Y6 0 2 4 6 8 1 3 5 7 9 L L L L L L L L L L L L L L H L L H 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 H L L H H L L H L H L 0 1 2 3 4 L L L L L L L L L L L L L L H L L H H L L H L H L L L L L L H H L L L L L H H H H L H L H 10 12 14 16 18 11 13 15 17 19 L L L L L H H H H H L L L L H L L H H L L H L H L L L L L L L L L L L L L L H H H H H L L L H H L L H L H L H 5 6 7 8 9 L L L L L L L L H H H H H L L L H H L L H L H L H L L L L L L L L L L H L L L L L H L H L 20 22 24 26 28 21 23 25 27 29 H H H H H L L L L L L L L L H L L H H L L H L H L L L L L L L L L L L H H H H H L L H H H H H L L H L H L H L 0 1 2 3 4 H H H H H L L L L L L L L L H L L H H L L H L H L L L L L L L H H L L L L L H H L L L H H 30 32 34 36 38 31 33 35 37 39 H H H H H H H H H H L L L L H L L H H L L H L H L L L L L L L H H H H H L L L L H L L L L H L L H H H L H L H 5 6 7 8 9 H H H H H L L L H H H H H L L L H H L L H L H L H L L L L L L L L L L H H L L L L L H H L X X X X X H Z Z Z Z Z Any X X X X X H Z Z Z E D C B A G Y5 Y4 Y3 Y2 Y1 Any H e High Level, L e Low Level, Z e High Impedance Note A: Input conditions other than those shown produce highs at outputs Y1 through Y5. Note B: Outputs 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. ² 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. 6-Bit Converter BCD 9’s Complement Converter BCD 10’s Complement Converter TL/F/6593–2 TL/F/6593 – 3 5 TL/F/6593 – 4 Function Tables (Continued) Inputs Binary Words Outputs E Binary Select D C B A Enable G Y8 Y7 Y6 Y5 Y4 Y3 Y2 Y1 0 2 4 6 1 3 5 7 L L L L L L L L L L L L L L H H L H L H L L L L H H H H H H H H L L L L L L L L L L L L L L L L L L H H L H L H 8 10 12 14 9 11 13 15 L L L L L L L L H H H H L L H H L H L H L L L L H H H H H H H H L L L L L L L L L H H H H L L L L L L H L L H L 16 18 20 22 17 19 21 23 L L L L H H H H L L L L L L H H L H L H L L L L H H H H H H H H L L L L L L H H H H L L L H L L H L L L H L L H 24 26 28 30 25 27 29 31 L L L L H H H H H H H H L L H H L H L H L L L L H H H H H H H H L L L L H H H H L L L H L L H L H H L L L H L L 32 34 36 38 33 35 37 39 H H H H L L L L L L L L L L H H L H L H L L L L H H H H H H H H L L L L H H H H H H H H L L L H L H H L H L H L 40 42 44 46 41 43 45 47 H H H H L L L L H H H H L L H H L H L H L L L L H H H H H H H H H H H H L L L L L L L L L L L L L L H H L H L H 48 50 52 54 49 51 53 55 H H H H H H H H L L L L L L H H L H L H L L L L H H H H H H H H H H H H L L L L L H H H H L L L L L L H L L H L 56 58 60 62 57 59 61 63 H H H H H H H H H H H H L L H H L H L H L L L L H H H H H H H H H H H H L L H H H H L L L H L L H L L L H L L H X X X X X H Z Z Z Z Z Z Z Z All H e High Level, L e Low Level, X e Don’t Care, Z e High Impedance 6-Bit Converter TL/F/6593 – 5 6 7 DM8898/DM8899 TRI-STATE BCD to Binary/Binary to BCD Converters Physical Dimensions inches (millimeters) Molded Dual-In-Line Package (N) Order Number DM8898N or DM8899AN NS Package Number N16A 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. 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