PIC16F676-I/ST Microchip Technology Inc., PIC16F676-I/ST Datasheet - Page 57

• Manufacturer Part Number: PIC16F676-I/ST
• Description: 14 PIN, 1.75 KB FLASH, 64 RAM, 12 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F676-I/ST

• Comparators: 1
• Cpu Speed: 5 MIPS
• Eeprom Memory: 128 Bytes
• Input Output: 12
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 14-pin TSSO
• Programmable Memory: 1.75K Bytes
• Ram Size: 64 Bytes
• Speed: 20 MHz
• Timers: 1-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

9.2
9.2.1
The PIC16F630/676 can be operated in eight different
Oscillator Option modes. The user can program three
configuration bits (FOSC2 through FOSC0) to select
one of these eight modes:
• LP
• XT
• HS
• RC
• INTOSC Internal Oscillator (2 modes)
• EC
9.2.2
In XT, LP or HS modes a crystal or ceramic resonator
is connected to the OSC1 and OSC2 pins to establish
oscillation (see Figure 9-1). The PIC16F630/676 oscil-
lator design requires the use of a parallel cut crystal.
Use of a series cut crystal may yield a frequency
outside of the crystal manufacturers specifications.
When in XT, LP or HS modes, the device can have an
external clock source to drive the OSC1 pin (see
Figure 9-2).
FIGURE 9-1:
 2003 Microchip Technology Inc.
Note
Note:
C1
C2
1:
2:
3:
Oscillator Configurations
(1)
(1)
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
External Resistor/Capacitor (2 modes)
External Clock In
Additional information on oscillator config-
urations is available in the PICmicro
Range Reference Manual, (DS33023).
OSCILLATOR TYPES
CRYSTAL OSCILLATOR / CERAMIC
RESONATORS
See Table 9-1 and Table 9-2 for recommended
values of C1 and C2.
A series resistor may be required for AT strip cut
crystals.
RF varies with the Oscillator mode selected
(Approx. value = 10 MΩ).
RS
XTAL
(2)
OSC1
OSC2
CRYSTAL OPERATION (OR
CERAMIC RESONATOR)
(HS, XT OR LP OSC
CONFIGURATION)
RF
(3)
PIC16F630/676
SLEEP
To Internal
Logic
TM
Mid-
FIGURE 9-2:
TABLE 9-1:
TABLE 9-2:
Note 1: Higher capacitance increases the stability
Note 1: Higher capacitance increases the stability
Mode
Clock from
External System
Mode
HS
XT
XT
HS
Note 1: Functions as RA4 in EC Osc mode.
LP
Open
of the oscillator but also increases the
start-up time. These values are for design
guidance only. Since each resonator has
its own characteristics, the user should
consult the resonator manufacturer for
appropriate values of external
components.
of the oscillator but also increases the
start-up time. These values are for design
guidance only. Rs may be required in HS
mode as well as XT mode to avoid
overdriving crystals with low drive level
specification. Since each crystal has its
own characteristics, the user should
consult the crystal manufacturer for
appropriate values of external
components.
16.0 MHz
2.0 MHz
4.0 MHz
8.0 MHz
455 kHz
100 kHz
10 MHz
20 MHz
32 kHz
Freq
2 MHz
4 MHz
8 MHz
Freq
Ranges Characterized:
PIC16F630/676
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
EXTERNAL CLOCK INPUT
OPERATION (HS, XT, EC,
OR LP OSC
CONFIGURATION)
68 - 100 pF
OSC1(C1)
68 - 100 pF
68 - 150 pF
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
OSC1(C1)
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
OSC1
OSC2
PIC16F630/676
(1)
DS40039C-page 55
150 - 200 pF
68 - 100 pF
68 - 100 pF
OSC2(C2)
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
OSC2(C2)
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF