PIC16F628AT-E/SS Microchip Technology, PIC16F628AT-E/SS Datasheet - Page 99

• Manufacturer Part Number: PIC16F628AT-E/SS
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,SSOP,20PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F628AT-E/SS

• Rohs Compliant: YES
• 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
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• 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 ~ 125°C
• Package / Case: 20-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: I3DBF648 - BOARD DAUGHTER ICEPIC3AC162053 - HEADER INTERFACE ICD,ICD2 18DIP
• 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:
© 2009 Microchip Technology Inc.
Note
1:
2:
C1
C2
Oscillator Configurations
(2)
(2)
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
External Resistor/Capacitor (2 modes)
External Clock In
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.
OSCILLATOR TYPES
CRYSTAL OSCILLATOR / CERAMIC
RESONATORS
XTAL
RS
(1)
OSC1
OSC2
CRYSTAL OPERATION
(OR CERAMIC RESONATOR)
(HS, XT OR LP OSC
CONFIGURATION)
PIC16F627A/628A/648A
RF
Sleep
F
OSC
PIC16F627A/628A/648A
TABLE 14-1:
TABLE 14-2:
Mode
Mode
Note:
Note:
HS
XT
XT
HS
LP
16.0 MHz
2.0 MHz
4.0 MHz
8.0 MHz
455 kHz
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 compo-
nents.
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 specification. Since each
crystal has its own characteristics, the
user should consult the crystal manufac-
turer for appropriate values of external
components.
200 kHz
100 kHz
10 MHz
20 MHz
32 kHz
Freq
2 MHz
4 MHz
8 MHz
Freq
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
OSC1(C1)
22-100 pF
OSC1(C1)
68-150 pF
15-68 pF
15-68 pF
10-68 pF
10-22 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
0-15 pF
DS40044G-page 99
150-200 pF
OSC2(C2)
22-100 pF
OSC2(C2)
15-68 pF
15-68 pF
10-68 pF
10-22 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
15-30 pF
0-15 pF