PIC12CE518-04E/SM Microchip Technology, PIC12CE518-04E/SM Datasheet - Page 41

• Manufacturer Part Number: PIC12CE518-04E/SM
• Description: IC MCU OTP 512X12 W/EE 8-SOIJ
• Manufacturer: Microchip Technology
• Series: PIC® 12Cr

Specifications of PIC12CE518-04E/SM

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Program Memory Size: 768B (512 x 12)
• Program Memory Type: OTP
• Eeprom Size: 16 x 8
• Ram Size: 25 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• For Use With: XLT08SO-1 - SOCKET TRANSITION 8SOIC 150/208AC164312 - MODULE SKT FOR PM3 16SOIC309-1048 - ADAPTER 8-SOIC TO 8-DIP309-1047 - ADAPTER 8-SOIC TO 8-DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Connectivity: -

2.3.5
1997 Microchip Technology Inc.
External Crystal Oscillator Circuit for Device Clock
Sometimes more than one device needs to be clocked from a single crystal. Since Microchip
does not recommend connecting other logic to the PICmicro’s internal oscillator circuit, an exter-
nal crystal oscillator circuit is recommended. Each device will then have an external clock source,
and the number of devices that can be driven will depend on the buffer drive capability. This circuit
is also useful when more than one device (PICmicro) needs to operate synchronously to each
other.
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 cir-
cuits can be used; one with series resonance, or one with parallel resonance.
Figure 2-4
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 nega-
tive feedback for stability. The 10 k potentiometer biases the 74AS04 in the linear region.
Figure 2-4: External Parallel Resonant Crystal Oscillator Circuit
Figure 2-5
the fundamental frequency of the crystal. The inverter performs a 180-degree phase shift in a
series resonant oscillator circuit. The 330 k resistors provide the negative feedback to bias the
inverters in their linear region.
Figure 2-5: External Series Resonant Crystal Oscillator Circuit
When the device is clocked from an external clock source (as in
the microcontroller’s oscillator must be configured for LP, XT or HS mode
shows an external series resonant oscillator circuit. This circuit is also designed to use
shows implementation of an external parallel resonant oscillator circuit. The circuit is
74AS04
330 k
10 k
+5V
20 pF
10k
0.1 F
XTAL
74AS04
XTAL
4.7 k
Section 2. Oscillator
20 pF
74AS04
330 k
10 k
74AS04
74AS04
To Other
Devices
To Other
Devices
PIC16CXXX
CLKIN
Figure 2-4
PIC16CXXX
CLKIN
(Figure
DS31002A-page 2-11
or
Figure
2-3).
2-5) then
2