LogicGate Simulator

Free Logic Gate Simulator
for EEE Students

Boolean expression → Truth Table → CMOS Circuit Diagram. Instant. Free. No login.

Example Circuits

NAND Gate

NOT (A AND B)

NOR Gate

NOT (A OR B)

XOR Gate

(A OR B) AND NOT (A AND B)

Half Adder Sum

A XOR B

Majority Function

(A AND B) OR (B AND C) OR (A AND C)

De Morgan 1

NOT (A AND B)

Free Boolean to Logic Circuit Converter for EEE Students

Logic Gate Simulator is a free online tool that converts any Boolean expression into a CMOS logic circuit diagram and truth table, instantly, in your browser, with no login required. It is built for EEE students, digital electronics learners, and anyone studying Boolean algebra, combinational logic, or CMOS circuit design.

Just type in your Boolean expression, for example A AND B OR NOT C, and you will instantly get the full logic circuit diagram and a complete truth table. No software to install, no account needed.

How to Use the Logic Gate Simulator

  1. Click CMOS Generator in the top navigation
  2. Type your Boolean expression (e.g. NOT (A AND B) for a NAND gate)
  3. Click Generate and the circuit diagram and truth table will appear instantly
  4. Use the CMOS Builder to drag and drop gates and build circuits from scratch
  5. Test your knowledge in the Quizzes section by identifying circuits from diagrams
  6. Read the Learn page for NAND/NOR gate theory and SOP vs POS worked examples

Supported Logic Gates

&AND Gate

Output is HIGH only when all inputs are HIGH. Boolean: A AND B

≥1OR Gate

Output is HIGH when at least one input is HIGH. Boolean: A OR B

1NOT Gate

Inverts the input signal. Boolean: NOT A. Also called an inverter.

↑NAND Gate

Short for NOT AND. Output is LOW only when all inputs are HIGH. Boolean: NOT (A AND B)

↓NOR Gate

Short for NOT OR. Output is HIGH only when all inputs are LOW. Boolean: NOT (A OR B)

=1XOR Gate

Exclusive OR. Output is HIGH when the inputs are different. Boolean: A XOR B

=XNOR Gate

Exclusive NOR. Output is HIGH when the inputs are equal. Boolean: NOT (A XOR B)

What is CMOS Circuit Design?

CMOS (Complementary Metal-Oxide-Semiconductor) is the technology used to build digital logic circuits in modern processors, microcontrollers, and FPGAs. In CMOS design, every logic gate is built from pairs of complementary MOSFET transistors: PMOS transistors form the pull-up network and NMOS transistors form the pull-down network.

CMOS circuit design is a core topic in Electrical and Electronic Engineering (EEE), computer engineering, and VLSI design courses. This tool helps you see how Boolean expressions map to physical gate-level circuits, which is an important skill for digital electronics exams and assignments.

Boolean Algebra and Truth Tables Explained

A truth table lists every possible combination of input values and the corresponding output for a Boolean expression. For n input variables, there are 2n rows. For example, a 2-variable expression (A, B) has 4 rows and a 4-variable expression has 16 rows.

Boolean algebra uses three basic operations: AND (·), OR (+), and NOT (¬). More complex functions such as Sum of Products (SOP) and Product of Sums (POS) are built from these. This simulator supports all standard Boolean operators and parentheses for complex expressions.

Frequently Asked Questions

Is this logic gate simulator free?
Yes, it is completely free. No account, no login, no download required. It works in any modern browser.
Can I use this for my EEE assignment or exam revision?
Yes. The tool is designed for EEE and digital electronics students. Use it to verify Boolean expressions, check truth tables, and visualise circuit diagrams for your coursework.
What Boolean expression syntax does the simulator accept?
Use AND, OR, NOT, NAND, NOR, XOR, XNOR as operators. Use parentheses for grouping. For example: NOT (A AND B) OR (C XOR D). Variables can be any single letter from A to Z.
How is a NAND gate different from an AND gate in CMOS?
A NAND gate is an AND gate followed by a NOT gate. In CMOS, NAND is preferred over AND because it needs fewer transistors and is faster, since series NMOS transistors switch faster than series PMOS transistors.
What is the difference between SOP and POS forms?
Sum of Products (SOP) is an OR of AND terms, for example (A AND B) OR (NOT A AND C). Product of Sums (POS) is an AND of OR terms. Both forms can be entered directly into this simulator.
Does this tool support Karnaugh map simplification?
Not yet, but you can enter your already-simplified Boolean expression from a K-map and instantly see the resulting circuit and truth table.

Quick Actions

Quick Quiz

Jump straight into a quiz — pick your difficulty and start immediately.