Oscillator circuitry for PIC18F4550

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hkBattousai

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What capacitor value should I choose for a 48MHz crystal frequency. The datasheet of the PIC only lists capacitor values up to 20MHz as follows :
XT Mode :
4 MHz --> 27 pF

HS Mode :
4 MHz --> 27 pF
8 MHz --> 22 pF
20 MHz --> 15 pF
Click to expand...

What are the XT and HS modes here?
 

If the 48Mhz crystal is for USB functionality then keep in mind that it has a high precision PLL for the USB Clock which can be driven using a 4Mhz crystal. Check out the PLL section on the data sheet.

a USB example @ 20Mhz .
 

in the book
type of Oscillator frequency
RC 0 – 4 MHz
LP 5 – 200 KHz
XT 100 KHz – 4 MHz
HS (-04) 4 MHz
HS (-10) 4 – 10 MHz
HS (-20) 4 – 20 MHz

the maximum is 20Mhz
 

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