$$f=1/{ln(2)⋅C⋅(R_1+2R_2)}$$
$$T_{high}=ln(2)⋅C⋅(R_1+R_2)$$
$$T_{low}=ln(2)⋅C⋅R_2$$
$$D=T_{high}/{T_{low}+T_{high}}={R_1+R_2}/{R_1+2R_2}$$

$$f=1/{ln(2)⋅C⋅(R_1+R_2)}$$
$$T_{high}=ln(2)⋅C⋅R_1$$
$$T_{low}=ln(2)⋅C⋅R_2$$
$$D=T_{high}/{T_{low}+T_{high}}={R_1}/{R_1+R_2}$$

$$t_{pulse}=ln(3)⋅R⋅C$$

f []
Thigh []
Tlow []
D []
tpulse []
Rx []
C []