PIC16C76-10/JW Microchip Technology, PIC16C76-10/JW Datasheet - Page 131

• Manufacturer Part Number: PIC16C76-10/JW
• Description: 8-Bit CMOS Microcontrollers with A/D Converter
• Manufacturer: Microchip Technology

14.2
14.2.1
The PIC16CXX can be operated in four different oscil-
lator modes. The user can program two configuration
bits (FOSC1 and FOSC0) to select one of these four
modes:
• LP
• XT
• HS
• RC
14.2.2
In XT, LP or HS modes a crystal or ceramic resonator
is connected to the OSC1/CLKIN and OSC2/CLKOUT
pins
PIC16CXX Oscillator design requires the use of a par-
allel cut crystal. Use of a series cut crystal may give a
frequency out of the crystal manufacturers specifica-
tions. When in XT, LP or HS modes, the device can
have an external clock source to drive the OSC1/
CLKIN pin (Figure 14-4).
FIGURE 14-3: CRYSTAL/CERAMIC
FIGURE 14-4: EXTERNAL CLOCK INPUT
See Table 14-1 and Table 14-2 for recommended values
of C1 and C2.
Note 1: A series resistor may be required for AT strip
1997 Microchip Technology Inc.
Clock from
ext. system
to
Oscillator Configurations
CRYSTAL OSCILLATOR/CERAMIC
RESONATORS
Applicable Devices
72 73 73A 74 74A 76 77
OSCILLATOR TYPES
C1
C2
cut crystals.
establish
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
Resistor/Capacitor
Open
Note1
XTAL
RS
RESONATOR OPERATION
(HS, XT OR LP
OSC CONFIGURATION)
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
OSC1
OSC2
oscillation
OSC1
OSC2
R
F
(Figure 14-3). The
PIC16CXX
SLEEP
PIC16CXX
To internal
logic
TABLE 14-1:
TABLE 14-2:
Ranges Tested:
XT
HS
Resonators Used:
455 kHz
2.0 MHz
4.0 MHz
8.0 MHz
16.0 MHz Murata Erie CSA16.00MX
Note 1: Recommended values of C1 and C2 are
Osc Type
Mode
200 kHz
20 MHz
32 kHz
1 MHz
4 MHz
8 MHz
All resonators used did not have built-in capacitors.
HS
XT
LP
2: Higher capacitance increases the stability
3: Since each resonator/crystal has its own
4: Rs may be required in HS mode as well as
These values are for design guidance only. See
notes at bottom of page.
These values are for design guidance only. See
notes at bottom of page.
identical to the ranges tested (Table 14-1).
of oscillator but also increases the start-up
time.
characteristics, the user should consult the
resonator/crystal manufacturer for appropri-
ate values of external components.
XT mode to avoid overdriving crystals with
low drive level specification.
2.0 MHz
4.0 MHz
16.0 MHz
455 kHz
8.0 MHz
Panasonic EFO-A455K04B
Murata Erie CSA2.00MG
Murata Erie CSA4.00MG
Murata Erie CSA8.00MT
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
Freq
Crystal
20 MHz
32 kHz
1 MHz
4 MHz
4 MHz
8 MHz
Freq
CERAMIC RESONATORS
CAPACITOR SELECTION
FOR CRYSTAL OSCILLATOR
Crystals Used
68 - 100 pF
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
Cap. Range
PIC16C7X
47-68 pF
15-33 pF
15-33 pF
OSC1
33 pF
15 pF
15 pF
15 pF
15 pF
C1
DS30390E-page 131
68 - 100 pF
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
Cap. Range
47-68 pF
15-33 pF
15-33 pF
0.3%
0.5%
0.5%
0.5%
0.5%
OSC2
20 PPM
20 PPM
50 PPM
50 PPM
30 PPM
30 PPM
33 pF
15 pF
15 pF
15 pF
15 pF
C2