PIC16F627A-I/SO Microchip Technology, PIC16F627A-I/SO Datasheet - Page 97

• Manufacturer Part Number: PIC16F627A-I/SO
• Description: IC MCU FLASH 1KX14 EEPROM 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F627A-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 1.75KB (1K x 14)
• Package / Case: 18-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Eeprom Size: 128 x 8
• Ram Size: 224 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 224 B
• Interface Type: SCI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT18SO-1 - SOCKET TRANSITION 18SOIC 300MILI3DBF648 - BOARD DAUGHTER ICEPIC3AC162053 - HEADER INTERFACE ICD,ICD2 18DIPAC164010 - MODULE SKT PROMATEII DIP/SOIC
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

14.2
14.2.1
The PIC16F627A/628A/648A can be operated in eight
different oscillator options. The user can program three
configuration bits (FOSC2 through FOSC0) to select
one of these eight modes:
• LP
• XT
• HS
• RC
• INTOSC Internal Precision Oscillator (2 modes)
• EC
14.2.2
In XT, LP or HS modes a crystal or ceramic resonator
is connected to the OSC1 and OSC2 pins to establish
oscillation (Figure 14-1). The PIC16F627A/628A/648A
oscillator design requires the use of a parallel cut
crystal. Use of a series cut crystal may give a frequency
out 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 (Figure 14-4).
FIGURE 14-1:
 2004 Microchip Technology Inc.
Note
1:
2:
C1
C2
Oscillator Configurations
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
External Resistor/Capacitor (2 modes)
External Clock In
OSCILLATOR TYPES
CRYSTAL OSCILLATOR / CERAMIC
RESONATORS
A series resistor may be required for AT strip cut
crystals.
See Table 14-1 and Table 14-2 for recommended
values of C1 and C2.
XTAL
RS
(1)
OSC1
OSC2
CRYSTAL OPERATION
(OR CERAMIC
RESONATOR) (HS, XT OR
LP OSC
CONFIGURATION)
PIC16F627A/628A/648A
RF
Sleep
F
OSC
Preliminary
PIC16F627A/628A/648A
TABLE 14-1:
TABLE 14-2:
14.2.3
Either a prepackaged oscillator can be used or a simple
oscillator circuit with TTL gates can be built.
Prepackaged oscillators provide a wide operating
range and better stability. A well-designed crystal
oscillator will provide good performance with TTL
gates. Two types of crystal oscillator circuits can be
used; one with series resonance, or one with parallel
resonance.
Figure 14-2 shows implementation of a parallel reso-
nant oscillator circuit. The circuit is designed to use the
fundamental frequency of the crystal. The 74AS04
inverter performs the 180 phase shift that a parallel
oscillator requires. The 4.7 k
negative
potentiometers bias the 74AS04 in the linear region.
This could be used for external oscillator designs.
Mode
Note:
Note:
Mode
HS
XT
HS
LP
XT
Higher capacitance increases the stability 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.
Higher capacitance increases the stability of the
oscillator but also increases the start-up time. These
values are for design guidance only. A series resistor
(RS) may be required in HS mode as well as XT mode
to avoid overdriving crystals with low drive level speci-
fication. Since each crystal has its own characteristics,
the user should consult the crystal manufacturer for
appropriate values of external components.
EXTERNAL CRYSTAL OSCILLATOR
CIRCUIT
feedback
16.0 MHz
2.0 MHz
4.0 MHz
8.0 MHz
455 kHz
200 kHz
100 kHz
10 MHz
20 MHz
Freq
32 kHz
2 MHz
4 MHz
8 MHz
Freq
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
for
22 - 100 pF
OSC1(C1)
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
68 - 150 pF
OSC1(C1)
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
15 - 30 pF
0 - 15 pF
stability.
resistor provides the
DS40044B-page 95
The
150 - 200 pF
22 - 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
15 - 30 pF
0 - 15 pF
10 k