PIC16C554-20I/SO Microchip Technology, PIC16C554-20I/SO Datasheet - Page 36

• Manufacturer Part Number: PIC16C554-20I/SO
• Description: IC MCU OTP 512X14 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C554-20I/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Size: 896B (512 x 14)
• Program Memory Type: OTP
• Ram Size: 80 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 18-SOIC (7.5mm Width)
• Processor Series: PIC16C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 80 B
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 13
• Number Of Timers: 8
• Operating Supply Voltage: 2.5 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: ICE2000
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Details

PIC16C55X
6.2.3
Either a pre-packaged oscillator can be used or a sim-
ple 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 6-3 shows implementation of a parallel resonant
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 kΩ resistor provides the
negative
potentiometers bias the 74AS04 in the linear region.
This could be used for external oscillator designs.
FIGURE 6-3:
Figure 6-4 shows a series resonant oscillator circuit.
This circuit is also designed to use the fundamental
frequency of the crystal. The inverter performs a 180°
phase shift in a series resonant oscillator circuit. The
330Ω resistors provide the negative feedback to bias
the inverters in their linear region.
FIGURE 6-4:
DS40143D-page 34
74AS04
10k
330Ω
+5V
20 pF
EXTERNAL CRYSTAL OSCILLATOR
CIRCUIT
feedback
10k
0.1 µF
XTAL
74AS04
XTAL
4.7k
20 pF
74AS04
330Ω
EXTERNAL PARALLEL
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
EXTERNAL SERIES
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
for
10k
74AS04
stability.
74AS04
To other
Devices
To other
Devices
The
CLK
PIC16C55X
PIC16C55X
IN
CLK
10 kΩ
IN
Preliminary
6.2.4
For timing insensitive applications the “RC” device
option offers additional cost savings. The RC oscillator
frequency is a function of the supply voltage, the
resistor (R
operating temperature. In addition to this, the oscillator
frequency will vary from unit to unit due to normal
process
difference in lead frame capacitance between package
types will also affect the oscillation frequency,
especially for low C
take into account variation due to tolerance of external
R and C components used. Figure 6-5 shows how the
R/C combination is connected to the PIC16C55X. For
R
become unstable, or stop completely. For very high
R
sensitive to noise, humidity and leakage. Thus, we
recommend to keep R
Although the oscillator will operate with no external
capacitor (C
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 or
package lead frame capacitance.
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 (Figure 3-2 for
waveform).
FIGURE 6-5:
EXT
EXT
C
R
V
EXT
EXT
SS
values below 2.2 kΩ, the oscillator operation may
V
values (e.g., 1 MΩ), the oscillator becomes
DD
parameter
EXT
RC OSCILLATOR
EXT
) and capacitor (C
Fosc/4
= 0 pF), we recommend using values
EXT
EXT
RC OSCILLATOR MODE
OSC1
variation.
values. The user also needs to
OSC2/CLKOUT
 2002 Microchip Technology Inc.
between 3 kΩ and 100 kΩ.
PIC16C55X
EXT
Furthermore,
) values, and the
Internal Clock
the