Description
This improved full adder performs the addition of two 4-bit binary numbers. The sum (Σ) output are provided for each bit and the resultant carry (C4) is obtained from the fourth bit.
This adder features full internal look ahead across all four bit generating the carry term in ten nanoseconds typically.
This provides the system designer with partial look-ahead performance at the economy and reduced package count of a ripple-carry implementation.

Features
• High Speed Operation: tpd (Ai or Bi to Zi) = 16 ns typ (CL = 50 pF)
• High Output Current: Fanout of 10 LSTTL Loads
• Wide Operating Voltage: VCC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)