PIC18F010T-I/SN View Datasheet(PDF) - Microchip Technology
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PIC18F010T-I/SN Datasheet PDF : 176 Pages
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PIC18F010/020
TABLE 2-1: CERAMIC RESONATORS
Ranges Tested:
Mode
Freq.
OSC1
OSC2
XT
455 kHz 68 - 100 pF 68 - 100 pF
2.0 MHz 15 - 68 pF 15 - 68 pF
4.0 MHz 15 - 68 pF 15 - 68 pF
HS
8.0 MHz 10 - 68 pF 10 - 68 pF
16.0 MHz 10 - 22 pF 10 - 22 pF
These values are for design guidance only.
See notes at bottom of page.
Resonators Used:
455 kHz Panasonic EFO-A455K04B ± 0.3%
2.0 MHz Murata Erie CSA2.00MG ± 0.5%
4.0 MHz Murata Erie CSA4.00MG ± 0.5%
8.0 MHz Murata Erie CSA8.00MT ± 0.5%
16.0 MHz Murata Erie CSA16.00MX ± 0.5%
All resonators used did not have built-in capacitors.
TABLE 2-2: CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Osc Type
Crystal
Freq.
Cap. Range
Cap.
C1
Range C2
LP
32.0 kHz
33 pF
33 pF
200 kHz
15 pF
15 pF
XT
200 kHz
47-68 pF
47-68 pF
1.0 MHz
15 pF
15 pF
4.0 MHz
15 pF
15 pF
HS
4.0 MHz
15 pF
15 pF
8.0 MHz
15-33 pF
15-33 pF
20.0 MHz 15-33 pF 15-33 pF
25.0 MHz
TBD
TBD
These values are for design guidance only.
See notes at bottom of page.
Crystals Used
32.0 kHz
200 kHz
1.0 MHz
4.0 MHz
8.0 MHz
20.0 MHz
Epson C-001R32.768K-A
STD XTL 200.000KHz
ECS ECS-10-13-1
ECS ECS-40-20-1
EPSON CA-301 8.000M-C
EPSON CA-301 20.000M-C
± 20 PPM
± 20 PPM
± 50 PPM
± 50 PPM
± 30 PPM
± 30 PPM
Note 1: Recommended values of C1 and C2 are
identical to the ranges tested (Table 2-1).
2: Higher capacitance increases the stability
of the oscillator, but also increases the
start-up time.
3: Since each resonator/crystal has its own
characteristics, the user should consult the
resonator/crystal manufacturer for appro-
priate values of external components.
4: Rs may be required in HS mode, as well as
XT mode, to avoid overdriving crystals with
low drive level specification.
2.3 RC Oscillator
For applications where precise timing is not a require-
ment, the RC and RCIO oscillator options are available.
The operation and functionality of the RC oscillator is
dependent on a number of variables. The RC oscillator
is a function of the supply voltage, the resistor (REXT)
and capacitor (CEXT) values, and the operating temper-
ature. The oscillator frequency will vary from unit to unit
due to normal process parameter variation. Plus, the
difference in lead frame capacitance between package
types will also affect the oscillation frequency, espe-
cially for low CEXT values. The user also needs to
account for the tolerance of the external R and C com-
ponents. Figure 2-3 shows how the R/C combination is
connected.
Note: The RC oscillator is not recommended for
applications that require precise timing.
FIGURE 2-3:
RC OSCILLATOR MODE
VDD
REXT
OSC1
Internal
Clock
CEXT
VSS
PIC18F010/020
OSC2/CLKO
FOSC/4
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ
CEXT > 20pF
In the RC mode, the oscillator frequency divided by 4 is
available on the OSC2 pin. This signal may be used for
test purposes, or to synchronize other logic. In the
RCIO mode, the OSC2 pin becomes a general purpose
I/O pin. This pin is RB4 of PORTB.
2.4 The Internal Oscillator
The INTOSC and INTOSCIO device options are avail-
able to minimize part count and cost, while maximizing
the number of I/O pins. There are five different frequen-
cies of which the user has the option to select. They are
32 kHz, 500 kHz, 1 MHz, 4 MHz, and 8 MHz. The 1
MHz, 4 MHz, and 8 MHz internal clock selections are
all derived from one 8 MHz clock source, and the other
two are produced independently. Tuning is available for
the 1 MHz, 4 MHz, and 8 MHz options; refer to
Section 2.10.
DS41142A-page 8
Preliminary
2001 Microchip Technology Inc.
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