16F876 Microchip Technology, 16F876 Datasheet - Page 124

• Manufacturer Part Number: 16F876
• Description: 28/40-pin 8-Bit CMOS FLASH Microcontrollers
• Manufacturer: Microchip Technology

PIC16F87X
TABLE 12-2:
DS30292B-page 124
32 kHz
200 kHz
1 MHz
4 MHz
8 MHz
20 MHz
Osc Type
Note 1: Higher capacitance increases the stability
HS
LP
XT
These values are for design guidance only.
See notes at bottom of page.
2: Since each resonator/crystal has its own
3: Rs may be required in HS mode, as well
4: When migrating from other PICmicro
of oscillator but also increases the start-up
time.
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate values of external compo-
nents.
as XT mode, to avoid overdriving crystals
with low drive level specification.
devices, oscillator performance should be
verified.
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
200 kHz
200 kHz
Crystal
20 MHz
32 kHz
1 MHz
4 MHz
4 MHz
8 MHz
Freq
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Crystals Used
Cap. Range
47-68 pF
15-33 pF
15-33 pF
33 pF
15 pF
15 pF
15 pF
15 pF
C1
± 20 PPM
± 20 PPM
± 50 PPM
± 50 PPM
± 30 PPM
± 30 PPM
47-68 pF
15-33 pF
15-33 pF
Range
33 pF
15 pF
15 pF
15 pF
15 pF
Cap.
C2
12.2.3
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 (R
ing temperature. In addition to this, the oscillator
frequency will vary from unit to unit due to normal pro-
cess parameter variation. Furthermore, the difference
in lead frame capacitance between package types will
also affect the oscillation frequency, especially for low
C
variation due to tolerance of external R and C compo-
nents used. Figure 12-3 shows how the R/C combina-
tion is connected to the PIC16F87X.
FIGURE 12-3: RC OSCILLATOR MODE
Recommended values:
EXT
Cext
V
Rext
SS
EXT
values. The user also needs to take into account
V
DD
RC OSCILLATOR
) and capacitor (C
F
OSC
/4
OSC1
OSC2/CLKOUT
1999 Microchip Technology Inc.
EXT
3 k
Cext > 20pF
) values, and the operat-
Rext
100 k
PIC16F87X
Internal
Clock