„MSP430 MCU” változatai közötti eltérés
Nincs szerkesztési összefoglaló |
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| 18. sor: | 18. sor: | ||
http://www.msp430launchpad.com/2012/03/using-aclk-and-32khz-crystal.html | http://www.msp430launchpad.com/2012/03/using-aclk-and-32khz-crystal.html | ||
<style="text-decoration:line-through;">For example, the LaunchPad uses 12pF capacitors to load the crystal we just installed, yet many crystals require 22pF.</> | <style="text-decoration:line-through;">For example, the LaunchPad uses 12pF capacitors to load the crystal we just installed, yet many crystals require 22pF.</style> | ||
Edit: This statement is actually incorrect. Another big thank you goes out to Jens-Michael for pointing it out to me. Thanks for reading! | Edit: This statement is actually incorrect. Another big thank you goes out to Jens-Michael for pointing it out to me. Thanks for reading! | ||
"12pF is the typical load for most crystals I've ever seen. But due to the electric connection, a 12pF load means [there will be 2] 24pF capacitance on each of the crystals sides. Reason is that (seen from the crystal), the two capacitors are in series to each other and parallel to the crystal. […] Subtract the ~2pF pin capacitance of the MSPs pins and you get [two separate] 22pF [for] external capacitors, resulting in 12pF load. The XCAP settings already include pin capacitance and the /2 factor." | "12pF is the typical load for most crystals I've ever seen. But due to the electric connection, a 12pF load means [there will be 2] 24pF capacitance on each of the crystals sides. Reason is that (seen from the crystal), the two capacitors are in series to each other and parallel to the crystal. […] Subtract the ~2pF pin capacitance of the MSPs pins and you get [two separate] 22pF [for] external capacitors, resulting in 12pF load. The XCAP settings already include pin capacitance and the /2 factor." | ||
A lap 2017. május 20., 19:26-kori változata
MSP430 MCU family from TI
http://www.ti.com/lit/sg/slab034ad/slab034ad.pdf
MSP430G2553 launchpad
32khz-crystal
Load capacitance !!!
http://www.msp430launchpad.com/2012/03/using-aclk-and-32khz-crystal.html
<style="text-decoration:line-through;">For example, the LaunchPad uses 12pF capacitors to load the crystal we just installed, yet many crystals require 22pF.</style>
Edit: This statement is actually incorrect. Another big thank you goes out to Jens-Michael for pointing it out to me. Thanks for reading! "12pF is the typical load for most crystals I've ever seen. But due to the electric connection, a 12pF load means [there will be 2] 24pF capacitance on each of the crystals sides. Reason is that (seen from the crystal), the two capacitors are in series to each other and parallel to the crystal. […] Subtract the ~2pF pin capacitance of the MSPs pins and you get [two separate] 22pF [for] external capacitors, resulting in 12pF load. The XCAP settings already include pin capacitance and the /2 factor."