Digital Electronics (Electronics)
Logic gates, flip-flops, counters, registers.
Digital Electronics (Electronics) — Overview
Logic gates, flip-flops, counters, registers.
Digital Electronics — logic gates, flip-flops, counters
Notes
Number Systems:
- Binary (base 2), Octal (8), Decimal (10), Hexadecimal (16).
- Conversions between bases.
Boolean Algebra:
- AND (·), OR (+), NOT ('), XOR (⊕), XNOR.
- De Morgan's laws: (A·B)' = A' + B'; (A+B)' = A' · B'.
Logic Gates:
| Gate | Symbol | A B = 1 1 | A B = 0 0 |
|---|---|---|---|
| AND | A·B | 1 | 0 |
| OR | A+B | 1 | 0 |
| NOT | A' | (single input) | |
| NAND | (A·B)' | 0 | 1 |
| NOR | (A+B)' | 0 | 1 |
| XOR | A⊕B | 0 | 0 |
NAND and NOR are universal gates (any circuit can be built).
Combinational Circuits:
- Half-adder: sum + carry.
- Full-adder: sum + carry-in + carry-out.
- Multiplexer (MUX): N inputs → 1 output, selected by control lines.
- Demultiplexer (DEMUX): 1 input → N outputs.
- Decoder, Encoder: binary to/from one-hot.
Sequential Circuits:
- Flip-flops: SR, JK, D, T.
- Edge-triggered vs level-triggered.
- Master-slave flip-flop.
Registers:
- Shift register: SISO, SIPO, PISO, PIPO.
- Used in: data storage, serial communication.
Counters:
- Asynchronous (ripple): simpler, slower.
- Synchronous: faster, more complex.
- Up, down, up-down counters.
- Mod-N counter (N states).
Memory:
- RAM (Random Access Memory): volatile.
- ROM (Read-Only): non-volatile.
- Cache, Registers, DRAM, SRAM.
ADC / DAC:
- ADC: analog → digital.
- DAC: digital → analog.
- Resolution = 2^n levels for n-bit.
RRB JE focus: truth tables, basic gates, simple flip-flop applications.