The TC74HC283A is a high-speed CMOS 4-bit binary full adder with fast carry. It adds two 4-bit binary words (A1–A4 plus B1–B4) and generates the sum (Σ1–Σ4) and carry-out (C4). The HC283A provides fast, ripple-free addition through the use of carry lookahead circuitry.

Applications

• Arithmetic logic units (ALUs)
• Binary addition in digital systems
• Address generation
• Data processing

Features

• High Speed: tpd = 17ns (typ.) at VCC = 5V
• Low Power Dissipation: ICC = 4μA (max.) at Ta = 25°C
• High Noise Immunity: VNIH = VNIL = 28% VCC (min.)
• Output Drive Capability: 10 LSTTL Loads
• Symmetrical Output Impedance: |IOH| = IOL = 4mA (min.)
• Balanced Propagation Delays: tPLH ≈ tPHL
• Wide Operating Voltage Range: VCC = 2V to 6V
• Carry Lookahead Circuitry for Fast Addition

Benefits

• Fast addition speeds are achieved through carry lookahead logic, improving system performance.
• Low power consumption is ideal for battery-powered and energy-efficient systems.
• High noise immunity ensures reliable operation in noisy industrial environments.
• Wide operating voltage range allows for flexible design implementation.
• High output drive capability allows it to drive multiple TTL loads directly.

The TC74HC283A's inputs and outputs are equipped with protection circuits against static discharge or transient excess voltage. To ensure stable operation, unused inputs must be tied to VCC or ground.

Pin Configuration: The HC283A has inputs for the two 4-bit binary words (A1-A4, B1-B4), a carry-in input (C0), four sum outputs (Σ1-Σ4), and a carry-out output (C4). VCC and GND provide power and ground respectively.

Absolute Maximum Ratings: Supply Voltage (VCC): -0.5V to 7V; DC Input Voltage (VIN): -0.5V to VCC + 0.5V; DC Output Voltage (VOUT): -0.5V to VCC + 0.5V; DC Output Current (IOUT): ±25mA; Power Dissipation (PD): 500mW; Storage Temperature (Tstg): -65°C to 150°C.