Datasheet PIC16F631, PIC16F677, PIC16F685, PIC16F687, PIC16F689, PIC16F690 (Microchip) - 48

HerstellerMicrochip
Beschreibung20-Pin Flash-Based, 8-Bit CMOS Microcontrollers
Seiten / Seite298 / 48 — PIC16F631/677/685/687/689/690. 3.4.3 LP, XT, HS MODES FIGURE 3-3: QUARTZ …
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PIC16F631/677/685/687/689/690. 3.4.3 LP, XT, HS MODES FIGURE 3-3: QUARTZ CRYSTAL. OPERATION (LP, XT OR

PIC16F631/677/685/687/689/690 3.4.3 LP, XT, HS MODES FIGURE 3-3: QUARTZ CRYSTAL OPERATION (LP, XT OR

Modelllinie für dieses Datenblatt

PIC16F631
PIC16F677
PIC16F685
PIC16F687
PIC16F689
PIC16F690

Textversion des Dokuments

PIC16F631/677/685/687/689/690
3.4.3 LP, XT, HS MODES FIGURE 3-3: QUARTZ CRYSTAL
OPERATION (LP, XT OR
HS MODE) The LP, XT and HS modes support the use of quartz
crystal resonators or ceramic resonators connected to
OSC1 and OSC2 (Figure 3-3). The mode selects a low,
medium or high gain setting of the internal inverteramplifier to support various resonator types and speed.
LP Oscillator mode selects the lowest gain setting of the
internal inverter-amplifier. LP mode current consumption
is the least of the three modes. This mode is designed to
drive only 32.768 kHz tuning-fork type crystals (watch
crystals).
XT Oscillator mode selects the intermediate gain
setting of the internal inverter-amplifier. XT mode
current consumption is the medium of the three modes.
This mode is best suited to drive resonators with a
medium drive level specification.
HS Oscillator mode selects the highest gain setting of the
internal inverter-amplifier. HS mode current consumption
is the highest of the three modes. This mode is best
suited for resonators that require a high drive setting.
Figure 3-3 and Figure 3-4 show typical circuits for
quartz crystal and ceramic resonators, respectively Note 1: Quartz crystal characteristics vary according to type, package and manufacturer. The
user should consult the manufacturer data
sheets for specifications and recommended
application.
2: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application. PIC® MCU
OSC1/CLKIN
C1 To Internal
Logic
Quartz
Crystal RF(2) OSC2/CLKOUT RS(1) C2 Sleep Note 1: A series resistor (RS) may be required for
quartz crystals with low drive level. 2: The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M. FIGURE 3-4: CERAMIC RESONATOR
OPERATION
(XT OR HS MODE)
PIC® MCU
OSC1/CLKIN C1 To Internal
Logic
RP(3) RF(2) Sleep 3: For oscillator design assistance, reference
the following Microchip Applications Notes:
• AN826, “Crystal Oscillator Basics and
Crystal Selection for rfPIC® and PIC®
Devices” (DS00826)
• AN849, “Basic PIC® Oscillator Design”
(DS00849)
• AN943, “Practical PIC® Oscillator
Analysis and Design” (DS00943)
• AN949, “Making Your Oscillator Work”
(DS00949) DS40001262F-page 48 C2 Ceramic
RS(1)
Resonator Note 1: OSC2/CLKOUT A series resistor (RS) may be required for
ceramic resonators with low drive level. 2: The value of RF varies with the Oscillator mode
selected (typically between 2 M to 10 M.
3: An additional parallel feedback resistor (RP)
may be required for proper ceramic resonator
operation.  2005-2015 Microchip Technology Inc.