54283

54283 NSC | Alldatasheet

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54283/DM74283 4-Bit Binary Full Adder (with Fast Carry) June 1989 54283/DM74283 4-Bit Binary Full Adder (with Fast Carry) General Description The ’283 high speed 4-bit binary full adders with internal carry lookahead accept two 4-bit binary words (A0–A3, B0– B3) and a Carry input (C0). They generate the binary Sum outputs (S0–S3) and the Carry output (C4) from the most significant bit. They operate with either active HIGH or ac- tive LOW operands (positive or negative logic). Connection Diagram Dual-In-Line Package TL/F/9786–1 Order Number 54283DMQB, 54283FMQB or DM74283N See NS Package Number J16A, N16E or W16A Pin Names Description A0–A3 A Operand Inputs B0–B3 B Operand Inputs C0 Carry Input S0–S3 Sum Outputs C4 Carry Output C1995 National Semiconductor Corporation RRD-B30M115/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 Operating Free Air Temperature Range b55§Ct o a125§C DM74 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 54283 DM74283 Units Min Nom Max Min Nom Max VCC Supply Voltage 4.5 5 5.5 4.75 5 5.25 V VIH High Level Input Voltage 2 2 V VIL Low Level Input Voltage 0.8 0.8 V IOH High Level Output Current b0.4 b0.4 mA IOL Low Level Output Current 16 16 mA TA Free Air Operating Temperature b55 125 0 70 §C

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 VOH High Level Output Voltage V CC e Min, I OH e Max 2.4 3.4 VVIL e Max VOL Low Level Output Voltage V CC e Min, I OL e Max 0.2 0.4 VVIH e Min 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 40 mA IIL Low Level Input Current V CC e Max, V I e 0.4V b1.6 mA IOS Short Circuit V CC e Max 54 b20 b55 mAOutput Current at S n (Note 2) DM74 b20 b55 IOS Short Circuit V CC e Max 54 b20 b70 mAOutput Current at C4 (Note 2) DM74 b18 b70 ICCH Supply Current with V CC e Max 54 99 mAOutputs High DM74 110 Note 1: All typicals are at V CC e 5V, T A e 25§C. Note 2: Not more than one output should be shorted at a time.

VCC ea 5.0V, T A ea 25§C (See Section 1 for waveforms and load configurations) Symbol Parameter CL e 15 pF, R L e 400X Units Min Max tPLH Propagation Delay 21 nstPHL C0 or S n 21 tPLH Propagation Delay 24 nstPHL An or B n to S n 24 tPLH Propagation Delay 14 nstPHL C0 to C4 16 tPLH Propagation Delay 14 nstPHL An or B n to C4 16 Functional Description The ’283 adds two 4-bit binary words (A plus B) plus the incoming carry C0. The binary sum appears on the Sum (S0–S3) and outgoing carry (C4 outputs. The binary weight of the various inputs and outputs is indicated by the sub- script numbers, representing powers of two. 0 (A0 a B0 a C0) a 21 (A1 a B1) a 22 (A2 a B2) a 23 (A3 a B3) e S0 a 2S1 a 4S2 a 8S3 a 16C4 Where ( a) e plus Interchanging inputs of equal weight does not affect the op- eration. Thus C0, A0, B0 can be arbitrarily assigned to pins 5, 6 and 7. Due to the symmetry of the binary add function, the ’283 can be used either with all inputs and outputs ac- tive HIGH (positive logic) or with all inputs and outputs ac- tive LOW (negative logic). Note that if C0 is not used it must be tied LOW for active HIGH logic or tied HIGH for active LOW logic. Example: C0 A0 A1 A2 A3 B0 B1 B2 B3 S0 S1 S2 S3 C4 Logic Levels L LHLHHLLH H HLLH Active HIGH 0 0101 1001 11001 Active LOW 1 1010 0110 00110 Active HIGH: 0 a 10 a 9 e 3 a 16 Active LOW: 1 a 5 a 6 e 12 a 0 Due to pin limitations, the intermediate carries of the ’283 are not brought out for use as inputs or outputs. However, other means can be used to effectively insert a carry into, or bring a carry out from, an intermediate stage. Figure a shows a way of making a 3-bit adder. Tying the operand inputs of the fourth adder (A3, B3) LOW makes S3 depen- dent ony on, and equal to, the carry from the third adder. Using somewhat the same principle, Figure b shows a way of dividing the ’283 into a 2-bit and a 1-bit adder. The third stage adder (A2, B2, S2) is used merely as a means of getting a carry (C10) signal into the fourth stage (via A2 and B2) and bringing out the carry from the second stage on S2. Note that as long as A2 and B2 are the same, whether HIGH or LOW, they do not infuence S2. Similarly, when A2 and B2 are the same the carry into the third stage does not influence they carry out of the third stage. Figure c shows a method of implementing a 5-input encoder, where the inputs are equally weighted. The outputs S0, S1 and S2 present a binary number equal to the number of inputs I1–I5 that are true. Figure d shows one method of implementing a 5-input majority gate. When three or more of the inputs I1–I5 are true, the output M5 is true. TL/F/9786–3 FIGURE a. 3-Bit Adder TL/F/9786–4 FIGURE b. 2-Bit and 1-Bit Adders

Functional Description (Continued) TL/F/9786–5 FIGURE c. 5-Input Encoder TL/F/9786–6 FIGURE d. 5-Input Majority Gate Logic Symbol TL/F/9786–2 VCC e Pin 16 GND e Pin 8 Logic Diagram TL/F/9786–7

Physical Dimensions inches (millimeters) 16-Lead Ceramic Dual-In-Line Package (J) Order Number 54283DMQB 16-Lead Molded Dual-In-Line Package (N) Order Number DM74283N

54283/DM74283 4-Bit Binary Full Adder (with Fast Carry) Physical Dimensions inches (millimeters) (Continued) 16-Lead Ceramic Flat Package (W) Order Number 54283FMQB 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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