RTC Oscillator Load capacitance - Electronic Circuits Projects Diagrams Free

hantto · 21st August 2005, 01:34 PM

Hi, i'm using a realtime clock chip which has the chrystal load capacitors built in. The load capacitance is 6pF. The chrystal I got my hands on has a specified load capacitance of 12.5 pF. Can I add 12.5 - 6 = 6.5pF capacitors to the chrystal's pins in order to get a more accurate clock?

JimB · 21st August 2005, 05:20 PM

Without knowing any more details, I think the quick answer is yes.

If you make the external capacitor a trimmer, you can the adjust the crystal frequency to be "spot on".

JimB

hantto · 21st August 2005, 05:30 PM

Thanks! The RTC i'm using is DS1337.

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21st August 2005, 01:34 PM	(permalink)
hantto	RTC Oscillator Load capacitance Hi, i'm using a realtime clock chip which has the chrystal load capacitors built in. The load capacitance is 6pF. The chrystal I got my hands on has a specified load capacitance of 12.5 pF. Can I add 12.5 - 6 = 6.5pF capacitors to the chrystal's pins in order to get a more accurate clock?

21st August 2005, 05:20 PM	(permalink)
JimB	Without knowing any more details, I think the quick answer is yes. If you make the external capacitor a trimmer, you can the adjust the crystal frequency to be "spot on". JimB __________________ Experience is directly proportional to the value of the equipment ruined.

21st August 2005, 05:30 PM	(permalink)
hantto	Thanks! The RTC i'm using is DS1337.