PIC14000-04I/SS Microchip Technology, PIC14000-04I/SS Datasheet - Page 77

• Manufacturer Part Number: PIC14000-04I/SS
• Description: IC, 8BIT MCU, PIC14, 4MHZ, SSOP-28
• Manufacturer: Microchip Technology

Specifications of PIC14000-04I/SS

• Controller Family/series: PIC14
• No. Of I/o's: 22
• Ram Memory Size: 192Byte
• Cpu Speed: 4MHz
• No. Of Timers: 2
• Interface: I2C
• Digital Ic Case Style: SSOP
• Core Size: 8 Bit
• Program Memory Size: 4096 X 14
• Embedded Interface Type: I2C
• Rohs Compliant: Yes
• Processor Series: PIC14000
• Core: PIC
• Data Bus Width: 8 bit
• Program Memory Type: EPROM
• Data Ram Size: 192 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 1
• Operating Supply Voltage: 2.7 V to 6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SSOP-28
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.2.2
In HS mode, a crystal or ceramic resonator is con-
nected to the OSC1 and OSC2 pins to establish oscil-
lation. A parallel cut crystal is required. Use of a series
cut crystal may give a frequency outside of the crystal
manufacturer’s specifications. When in HS mode, the
device can have an external clock source to drive the
OSC1 pin.
FIGURE 10-3: CRYSTAL/CERAMIC
FIGURE 10-4: EXTERNAL CLOCK INPUT
TABLE 10-1:
HS
Note :
Resonators Used:
4 MHz
8 MHz
16 MHz
See Table 10-1 and Table 10-2 for recommended
values of C1 and C2.
1996 Microchip Technology Inc.
Note 1: A series resistor may be required for AT
Mode
Clock from
ext. system
All resonators used did not have built-in capacitors.
Recommended values of C1 and C2 are identical to
the ranges tested table.
Higher capacitance increases the stability of
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.
CRYSTAL OSCILLATOR/CERAMIC
RESONATOR
C1
C2
Murata Erie CSA4.00MG
Murata Erie CSA8.00MT
Murata Erie CSA16.00MX
strip cut crystals.
16 MHz
4 MHz
8 MHz
Open
Freq
Note1
XTAL
RS
RESONATOR OPERATION
(HS OSC CONFIGURATION)
OPERATION (HS OSC
CONFIGURATION)
CERAMIC RESONATORS
OSC1
OSC2
15 - 68 pF
10 - 68 pF
10 - 22 pF
OSC1
OSC2
RF
C1
PIC14000
PIC14000
SLEEP
SLPCON<3>
+/-.5%
+/-.5%
+/-.5%
To internal
logic
15 - 68 pF
10 - 68 pF
10 - 22 pF
C2
Preliminary
TABLE 10-2:
10.2.3
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 10-5 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-degree phase shift that a
parallel oscillator requires. The 4.7 k resistor provides
the negative feedback for stability. The 10 k
potentiometer biases the 74AS04 in the linear region.
This could be used for external oscillator designs.
FIGURE 10-5: EXTERNAL PARALLEL
Note :
Mode
HS
10k
Higher capacitance increases the stability of
oscillator but also increases the start-up time.
These values are for design guidance only. Rs may
be required in HS mode to avoid overdriving
crystals with low drive level specification. Since
each crystal has its own characteristics, the user
should consult the crystal manufacturer for
appropriate values of external components.
For V
EXTERNAL CRYSTAL OSCILLATOR
CIRCUIT
+5V
20 MHz
DD
4 MHz
8 MHz
20pF
10k
Freq
> 4.5V, C1 = C2
74AS04
XTAL
CAPACITOR SELECTION
FOR CRYSTAL OSCILLATOR
RESONANT CRYSTAL
OSCILLATOR CIRCUIT
4.7k
20pF
15 - 33 pF
15 - 47 pF
15 - 47 pF
10k
74AS04
PIC14000
C1
30pf is recommended.
DS40122B-page 77
To Other
Devices
15 - 33 pF
15 - 47 pF
15 - 47 pF
OSC1
C2