ive been following along with this thread, its been quite interesting, but havent had time to jump in yet. from what i can tell, the differences in chips is just the lower threshold voltage (which i think JimY pointed out). the HSS is 9.5V off the bottom rail, whereas the NXP is 7.5V. the frequency is solely determined by the time it takes to reach the lower threshold from -15V (or wherever it starts from below the threshold). the lower threshold of the NXP means it reaches this threshold sooner, and has a higher frequency. since this decay time is a dual decay time (10k resistor till MOD voltage is met, then 120k resistor after that), this also means that the MOD range is potentially smaller, or at least has a shifted range. there is also the added issue of the negative pulse on the capacitor not pulling down the full 15V (finite output resistance, stray capacitance, ??) so the NXP, which doesnt get enough time to decay on the top part of the input waveform, doesnt get pulled all the way down to -15V (which the HSS barely does). so not only does it have a closer threshold to hit, its starting closer to that threshold.
Statistics: Posted by guest — Wed Oct 30, 2024 2:23 am
