PIC18F6621-I/PT Microchip Technology Inc., PIC18F6621-I/PT Datasheet - Page 24

• Manufacturer Part Number: PIC18F6621-I/PT
• Description: 64 PIN, 64 KB FLASH, 3840 RAM, 52 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F6621-I/PT

• A/d Inputs: 12-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 1024 Bytes
• Input Output: 54
• Interface: I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 64-pin TQFP
• Programmable Memory: 64K Bytes
• Ram Size: 3.8K Bytes
• Speed: 40 MHz
• Timers: 2-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F6525/6621/8525/8621
TABLE 2-2:
An external clock source may also be connected to the
OSC1 pin in the HS, XT and LP modes as shown in
Figure 2-2.
FIGURE 2-2:
DS39612B-page 22
These values are for design guidance only.
See notes following this table.
Clock from
Ext. System
Note 1: Higher capacitance increases the stability
Mode
HS
LP
XT
200 kHz
2: R
3: Since each resonator/crystal has its own
32 kHz
1 MHz
of the oscillator but also increases the
start-up time.
HS mode, as well as XT mode, to avoid
overdriving crystals with low drive level
specification.
characteristics, the user should consult the
resonator/crystal manufacturer for appro-
priate values of external components or
verify oscillator performance.
S
20.0 MHz
25.0 MHz
32.0 kHz
Open
200 kHz
1.0 MHz
4.0 MHz
4.0 MHz
8.0 MHz
(see Figure 2-1) may be required in
Freq
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Ranges Tested:
Crystals Used
EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR
LP OSCILLATOR
CONFIGURATION)
OSC1
OSC2
47-68 pF
15-33 pF
15-33 pF
15-33 pF
PIC18F6X2X/8X2X
33 pF
15 pF
15 pF
15 pF
C1
20 MHz
4 MHz
8 MHz
47-68 pF
15-33 pF
15-33 pF
15-33 pF
33 pF
15 pF
15 pF
15 pF
C2
2.3
For timing insensitive applications, the “RC” and
“RCIO” device options offer additional cost savings.
The RC oscillator frequency is a function of the supply
voltage, the resistor (R
values and the operating temperature. In addition to
this, the oscillator frequency will vary from unit to unit
due to normal process parameter variation. Further-
more, the difference in lead frame capacitance
between package types will also affect the oscillation
frequency, especially for low C
also needs to take into account variation due to
tolerance of external R and C components used.
Figure 2-3 shows how the R/C combination is
connected.
In the RC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic.
FIGURE 2-3:
The RCIO Oscillator mode functions like the RC mode
except that the OSC2 pin becomes an additional
general purpose I/O pin. The I/O pin becomes bit 6 of
PORTA (RA6).
R
C
V
Recommended values:
EXT
EXT
SS
V
DD
RC Oscillator
F
OSC
/4
RC OSCILLATOR MODE
OSC1
OSC2/CLKO
 2005 Microchip Technology Inc.
3 kΩ ≤ R
C
EXT
EXT
) and capacitor (C
> 20 pF
PIC18F6X2X/8X2X
EXT
EXT
values. The user
≤ 100 kΩ
Internal
Clock
EXT
)