PIC16F5X
TABLE 4-1:
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
4.0
4.1
OSCILLATOR
CONFIGURATIONS
Osc
Resonator Cap. Range Cap. Range
Type
Freq.
C1
C2
Oscillator Types
XT
455 kHz
2.0 MHz
4.0 MHz
68-100 pF
15-33 pF
10-22 pF
68-100 pF
15-33 pF
10-22 pF
The PIC16F5X devices can be operated in four differ-
ent oscillator modes. The user can program two Con-
figuration bits (FOSC1:FOSC0) to select one of these
four modes:
HS
8.0 MHz
16.0 MHz
10-22 pF
10 pF
10-22 pF
10 pF
• LP:
• XT:
Low-power Crystal
Crystal/Resonator
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.
• HS: High-speed Crystal/Resonator
• RC: Resistor/Capacitor
4.2
Crystal Oscillator/Ceramic
Resonators
TABLE 4-2:
CAPACITOR SELECTION FOR
CRYSTAL OSCILLATOR
Osc
Type
Crystal
Freq.
Cap.Range Cap. Range
In XT, LP or HS modes, a crystal or ceramic resonator
is connected to the OSC1/CLKIN and OSC2/CLKOUT
pins to establish oscillation (Figure 4-1). The
PIC16F5X oscillator design requires the use of a
parallel cut crystal. Use of a series cut crystal may give
a frequency outside of the crystal manufacturers
specifications. When in XT, LP or HS modes, the
device can have an external clock source drive the
OSC1/CLKIN pin (Figure 4-2).
C1
C2
LP
XT
32 kHz(1)
15 pF
15 pF
100 kHz
200 kHz
455 kHz
1 MHz
2 MHz
4 MHz
15-30 pF
15-30 pF
15-30 pF
15-30 pF
15 pF
200-300 pF
100-200 pF
15-100 pF
15-30 pF
15 pF
15 pF
15 pF
HS
4 MHz
8 MHz
20 MHz
15 pF
15 pF
15 pF
15 pF
15 pF
15 pF
FIGURE 4-1:
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS, XT OR LP OSC
CONFIGURATION)
Note 1: For VDD > 4.5V, C1 = C2 ≈ 30 pF is
recommended.
(1)
C1
OSC1
These values are for design guidance only. Rs may
be required in HS mode, as well as XT mode, to
avoid overdriving crystals with low drive level specifi-
cations. Since each crystal has its own characteris-
tics, the user should consult the crystal manufacturer
for appropriate values of external components.
PIC16F5X
Sleep
XTAL
OSC2
(3)
RF
To internal
logic
(2)
RS
(1)
C2
Note 1: This device has been designed to perform
to the parameters of its data sheet. It has
been tested to an electrical specification
designed to determine its conformance
with these parameters. Due to process
differences in the manufacture of this
device, this device may have different
performance characteristics than its
earlier version. These differences may
cause this device to perform differently in
your application than the earlier version of
this device.
Note 1: See Capacitor Selection tables for
recommended values of C1 and C2.
2: A series resistor (RS) may be required.
3: RF varies with the Oscillator mode chosen
(approx. value = 10 MΩ).
FIGURE 4-2:
EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR LP
OSC CONFIGURATION)
Clock from
ext. system
OSC1
2: The user should verify that the device
oscillator starts and performs as
expected. Adjusting the loading capacitor
values and/or the Oscillator mode may be
required.
PIC16F5X
OSC2
Open
© 2007 Microchip Technology Inc.
DS41213D-page 21
MICROCHIP [ MICROCHIP ]
