The TLC555 is the CMOS equivalent of the well-known 555 bipolar transistor. It can be used in the production of signals in a range from a fraction of hertz to about 2 MHz. The frequency depends on Ra, Rb, and C based on the formula in figure bellow, where the basic configuration is shown. The common 555 [bipolar transistor] can also be used to drive CMOS circuits without any problem. The only difference is that the 555 drains more current than the CMOS equivalent. In this circuit, the lowest value for Ra and Rb is 1 k ohm and the lower value for C is 47 pF. The highest values are determined only by losses in the capacitor. The TLC555 will operate from power sources between 2 V and 18 V.
CMOS 555
