PIC16LC63A-04 Datasheet, PDF (87/184 Pages) Microchip Technology – 8-Bit CMOS Microcontrollers with A/D Converter

PIC16C63A/65B/73B/74B
TABLE 13-1: 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
Note: These values are for design guidance only.
See notes following Table 13-1 and Table 13-2.
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%
Note: Resonators used did not have built-in capacitors.
TABLE 13-2: CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Osc Type
Crystal
Freq
Cap. Range Cap. Range
C1
C2
LP
32 kHz
33 pF
33 pF
200 kHz
15 pF
15 pF
XT
200 kHz
47-68 pF
47-68 pF
1 MHz
15 pF
15 pF
4 MHz
15 pF
15 pF
HS
4 MHz
15 pF
15 pF
8 MHz
15-33 pF
15-33 pF
20 MHz
15-33 pF
15-33 pF
Note: These values are for design guidance only.
See notes following Table 13-1 and Table 13-2.
Crystals Used:
32 kHz Epson C-001R32.768K-A
± 20 PPM
200 kHz STD XTL 200.000KHz
± 20 PPM
1 MHz ECS ECS-10-13-1
± 50 PPM
4 MHz ECS ECS-40-20-1
± 50 PPM
8 MHz EPSON CA-301 8.000M-C
± 30 PPM
20 MHz EPSON CA-301 20.000M-C ± 30 PPM
Note 1: Higher capacitance increases the stability
of the oscillator, but also increases the
start-up time.
2: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external compo-
nents.
3: Rs may be required in HS mode, as well
as XT mode, to avoid overdriving crystals
with low drive level specification.
4: Oscillator performance should be verified
at the expected voltage and temperature
extremes in which the application is
expected to operate.
13.2.3 RC OSCILLATOR
For timing insensitive applications, the “RC” device
option offers additional cost savings. The RC oscillator
frequency is a function of the supply voltage, the resis-
tor (REXT) and capacitor (CEXT) values, and the operat-
ing temperature. The oscillator frequency will vary from
unit to unit due to normal process variation. The differ-
ence in lead frame capacitance between package
types will also affect the oscillation frequency, espe-
cially for low CEXT values. The user also needs to take
into account variation due to tolerance of external R
and C components used. Figure 13-3 shows how the
R/C combination is connected to the PIC16CXX.
The oscillator frequency, divided by 4, is available on
the OSC2/CLKOUT pin, and can be used for test pur-
poses or to synchronize other logic (see Figure 3-2 for
waveform).
FIGURE 13-3:
V DD
RC OSCILLATOR MODE
REXT
OSC1
Internal
Clock
CEXT
VSS
PIC16CXX
OSC2/CLKOUT
FOSC/4
Recommended Values: REXT = 3 kW to 100 kW
CEXT = 20 pf to 30 pF
 2000 Microchip Technology Inc.
DS30605C-page 87