Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Dan East said:I've been dredging through the microchip site, and unfortunately the PIC comparison charts do not include the internal oscillator speed.
I'm looking for a PIC like the PIC16F628A but with a 20 MHz internal oscillator. Is there such a thing?
Thanks.
Dan East
e said:I think the highest internals is like 8MHz, well thats the highest I have seen anyway
Dan East said:Here's a related question. Using a 629 with the internal oscillator, I see communication errors occur at different voltages. For example I get proper communication at 3 V, but not at 4.5 volts (a few bit errors occur). It is obviously a timing problem. So is it to be expected that the frequency will deviate substantially at different voltages using the internal oscillator?
There must be other variables affected by supply voltage besides the internal oscillator frequency. The Freq/Vdd timing chart for the '629 shows the typical osc. frequency varying from 4Mhz @ 3V to ~ 3.98Mhz @ 4.5V. Taken alone, this would increase the bit length to about 104.5 uS, not enough to account for the variation you're seeing.I should have to reduce my bit length if the PIC runs slower at the higher voltage, according to the datasheet.