PIC16F872-E/SS Microchip Technology, PIC16F872-E/SS Datasheet - Page 42

• Manufacturer Part Number: PIC16F872-E/SS
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,SSOP,28PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F872-E/SS

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-SSOP
• Package: 28SSOP
• Device Core: PIC
• Family Name: PIC16
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 22
• Interface Type: I2C/SPI
• On-chip Adc: 5-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PICmicro MID-RANGE MCU FAMILY
2.4
2.4.1
DS31002A-page 2-12
RC Start-up
External RC Oscillator
For timing insensitive applications the “EXTRC” device option offers additional cost savings. The
RC oscillator frequency is a function of; the supply voltage, the resistor (R
(C
from unit to unit due to normal process parameter variation. Furthermore, the difference in lead
frame capacitance between package types will also affect the oscillation frequency, especially for
low C
R
PIC16CXXX. For R
completely. For very high R
humidity and leakage. Thus, we recommend keeping R
Figure 2-6: EXTRC Oscillator Mode
Although the oscillator will operate with no external capacitor (C
using values above 20 pF for noise and stability reasons. With no or small external capacitance,
the oscillation frequency can vary dramatically due to changes in external capacitances, such as
PCB trace capacitance and package lead frame capacitance.
See characterization data for RC frequency variation from part to part due to normal process
variation. The variation is larger for larger resistance (since leakage current variation will affect
RC frequency more for large R) and for smaller capacitance (since variation of input capacitance
will affect RC frequency more).
See characterization data for variation of oscillator frequency due to V
values as well as frequency variation due to operating temperature for given R
V
The oscillator frequency, divided by 4, is available on the OSC2/CLKOUT pin, and can be used
for test purposes or to synchronize other logic (see
the
As the device voltage increases, the RC will start its oscillations immediately after the pin voltage
levels meet the input threshold specifications
Specifications”
tors. These include:
• Resistor value used
• Capacitor value used
• Device V
• System temperature
DD
EXT
EXT
Note 1: This output may also be able to be configured as a general purpose I/O pin.
“Architecture”
values.
EXT
) values, and the operating temperature. In addition to this, the oscillator frequency will vary
and C
values. The user also needs to take into account variation due to tolerance of external
DD
EXT
rise time
components used.
section). The time required for the RC to start oscillating depends on many fac-
EXT
section, for waveform).
C
R
V
values below 2.2 k , oscillator operation may become unstable, or stop
EXT
SS
EXT
V
EXT
DD
values (e.g. 1 M ), the oscillator becomes sensitive to noise,
Fosc/4
Figure 2-6
(1)
OSC1
OSC2/CLKOUT
shows how the RC combination is connected to a
(parameters D032
Figure 4-3: "Clock/Instruction Cycle"
EXT
Fosc
between 3 k and 100 k .
PIC16CXXX
Internal
clock
EXT
and
1997 Microchip Technology Inc.
= 0 pF), we recommend
D042
DD
for given R
EXT
in the
) and capacitor
EXT
, C
“Electrical
EXT
EXT
/C
, and
EXT
in