The CD4047 is a CMOS integrated circuit that functions as a low-power monostable/astable multivibrator. It does not have a specific formula associated with it. However, the timing equations for the CD4047 can be used to calculate the timing periods for the monostable and astable modes of operation.

For the monostable mode, the pulse width (t) is given by the following equation:

t = 0.69 × R × C

F= 1/t ( F is frequency)

Where:
R is the external timing resistor connected between pins 2 and 3
C is the external timing capacitor connected between pins 1 and 3

cd4047

For the astable mode, the high output period (t1) and low output period (t2) are given by the following equations:

t1 = 0.69 × (R1 + R2) × C
t2 = 0.69 × R2 × C

Where:
R1 is the external timing resistor connected between pins 2 and 3
R2 is the external timing resistor connected between pins 6 and 7
C is the external timing capacitor connected between pins 1 and 3

These timing equations can be used to calculate the desired pulse widths or oscillation periods by selecting appropriate values for the external resistors and capacitors based on the specific application requirements.