PIC18F25K80 MICROCHIP [Microchip Technology], PIC18F25K80 Datasheet - Page 452

• Manufacturer Part Number: PIC18F25K80
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F66K80 FAMILY
Table 27-2
generated by the PLL and the frequency error from
jitter (measured jitter-induced error of 2%, Gaussian
distribution, within 3 standard deviations), as a
percentage of the nominal clock frequency.
TABLE 27-2:
TABLE 27-3:
DS39977C-page 452
40 MHz
24 MHz
16 MHz
Output
Nominal PLL Output
PLL
40 MHz
24 MHz
16 MHz
shows the relation between the clock
0.83 ns
1.25 ns
0.5 ns
P
jitter
FREQUENCY ERROR FROM JITTER AT VARIOUS PLL GENERATED CLOCK SPEEDS
TOTAL FREQUENCY ERROR AT VARIOUS PLL GENERATED CLOCK SPEEDS
(100 PPM OSCILLATOR DRIFT, INCLUDING ERROR FROM JITTER)
1.67 ns
2.5 ns
T
(125 Kb/s)
1 ns
0.01125%
0.01209%
0.01313%
jitter
8 s
Frequency Error at Various Nominal Bit Times (Bit Rates)
(125 Kb/s)
0.00125%
0.00209%
0.00313%
8 s
Frequency Error at Various Nominal Bit Times (Bit Rates)
Preliminary
(250 Kb/s)
0.01250%
0.01418%
0.01625%
4 s
This is clearly smaller than the expected drift of a
crystal oscillator, typically specified at 100 ppm or
0.01%. If we add jitter to oscillator drift, we have a total
frequency drift of 0.0132%. The total oscillator
frequency errors for common clock frequencies and bit
rates, including both drift and jitter, are shown in
Table
(250 Kb/s)
0.00250%
0.00418%
0.00625%
4 s
27-3.
(500 Kb/s)
0.015%
0.018%
0.023%
2 s
(500 Kb/s)
0.005%
0.008%
0.013%
2 s
 2011 Microchip Technology Inc.
(1 Mb/s)
0.027%
0.035%
0.02%
(1 Mb/s)
1 s
0.017%
0.025%
0.01%
1 s