**Other Parts Discussed in Thread:**CD4536B

The data sheet for the TI CD4536B includes a support component labeled "Rs". However, the data sheet does not say what Rs does, how it enters into the frequency calculation for the oscillator, nor how to optimize the value for Rs.

Page 3-313 of the data sheet shows in the note: Rs ~= 5 to 10 x Rt, yet graph Figure 12 indicates Rs equal to 2x Rt, and graph Figures 13 and 14 compare temperature deviation of the oscillator with Rs equal to zero ohms and to 120 k ohms (some, but not much difference, except at lower Vdd values).

So, the questions are: What does Rs 'do' for the CD4536B? How does the value of Rs work into the timing equation for the oscillator? How does one go about optimizing the value of Rs, and indeed what IS optimized by changing the value of Rs?