Skip to content
Solved Examples · Example 30

Q.Example 1: Simplify the Boolean expression Y=∑m(0,1,4,13,15)+∑d(2,5,7)Y = \sum m(0,1,4,13,15) + \sum d(2,5,7) and then draw the logic diagram using only basic gates.

Karnataka PUCTextbookLongImportance★★★★★est
74% · 119/160 Questions
🔒 Locked · start free trial →

You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.

Start your 14-day free trial to unlock the full solution →

[!TLDR]

Map the minterms and don't-cares, group two quads (A‾ C‾\overline{A}\,\overline{C} and BDBD), OR them, and build the result from NOT + AND + OR gates: Y=A‾ C‾+BDY = \overline{A}\,\overline{C} + BD.

Plotting the map

Enter 1 for each minterm in ∑m(0,1,4,13,15)\sum m(0,1,4,13,15), X for each don't-care in ∑d(2,5,7)\sum d(2,5,7), and 0 elsewhere:

AB\CDAB\backslash CDC‾ D‾\overline{C}\,\overline{D}C‾D\overline{C}DCDCDCD‾C\overline{D}
A‾ B‾\overline{A}\,\overline{B}110X
A‾B\overline{A}B1XX0
ABAB0110
AB‾A\overline{B}0000

Grouping

  • Quad 1: rows A‾ B‾\overline{A}\,\overline{B} and A‾B\overline{A}B, columns C‾ D‾\overline{C}\,\overline{D} and C‾D\overline{C}D (minterms 0, 1, 4 and don't-care 5). BB and DD change; constants A=0, C=0A=0,\ C=0 give A‾ C‾\overline{A}\,\overline{C}.
  • Quad 2: rows A‾B\overline{A}B and ABAB, columns C‾D\overline{C}D and CDCD (minterms 13, 15 and don't-cares 5, 7). AA and CC change; constants B=1, D=1B=1,\ D=1 give BDBD.

ORing the two groups gives the simplified SOP Y=A‾ C‾+BDY = \overline{A}\,\overline{C} + BD.

Realising with basic gates (Figure 10.4.1) …

Unlock everything free for 14 days

  • Full step-by-step solutions
  • Concept-first explanations
  • Methods, shortcuts & mistakes
  • PYQ mapping + timed mock tests

Full access for 14 days. No credit card required.