Freescale Semiconductor, Inc.
Ge ne ra l De sc rip tion
To VDD (or STOP)
MCU
To VDD (or STOP)
MCU
OSC1
OSC2
OSC1
OSC2
4.7 MΩ
UNCONNECTED
EXTERNAL CLOCK
37 pF
37 pF
(a) Crystal or Ceramic
Resonator Connections
(b) External Clock Source
Connections
Figure 1-2. Oscillator Connections
1.4.2.1 Crysta l
The circuit in Figure 1-2(a) shows a typical oscillator circuit for an AT-
cut, parallel resonant crystal. Follow the crystal manufacturer’s
recommendations, as the crystal parameters determine the external
component values required to provide maximum stability and reliable
startup. The load capacitance values used in the oscillator circuit design
should include all stray capacitances. Mount the crystal and components
as close as possible to the pins for startup stabilization and to minimize
output distortion.
1.4.2.2 Ce ra m ic Re so na to r
In cost-sensitive applications, use a ceramic resonator in place of a
crystal. Use the circuit in Figure 1-2(a) for a ceramic resonator and
follow the resonator manufacturer’s recommendations, as the resonator
parameters determine the external component values required for
maximum stability and reliable starting. The load capacitance values
used in the oscillator circuit design should include all stray capacitances.
Mount the resonator and components as close as possible to the pins for
startup stabilization and to minimize output distortion.
General Release Specification
MC68HC705P6A — Rev. 1.0
General Description
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