MC68HC12 MOTOROLA [Motorola, Inc], MC68HC12 Datasheet - Page 205

• Manufacturer Part Number: MC68HC12
• Description: The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit
• Manufacturer: MOTOROLA [Motorola, Inc]

13.4.3 Important Information For Calculating Component Values
13.4.3.1 How to Use This Information
MC68HC912DT128A — Rev 4.0
MOTOROLA
Before attempting to apply the information in section
Parameters, the following data from the resonator vendor is required:
The following tables provide Maximum ESR vs. component value for
various frequencies. This table should be used in the following manner:
1. Choose the set of component values corresponding to the correct
2. Determine the range of components for which the Maximum ESR
3. Within this range, choose the EXTAL–XTAL capacitance closest
4. If the ideal component is between two valid component values (the
5. Choose the size of the XTAL–VSS capacitance equal to the
•
•
•
•
Resonator Frequency (f)
Maximum ESR (R, ESR, or R1)
Maximum Shunt Capacitance (C0)
Load Capacitance (CL) — this is not the external component
values but rather the capacitance applied in parallel with the
resonator during the tuning procedure.
maximum shunt capacitance (equal to the sum of EXTAL–VSS
parasitics in excess of 1pF, plus the C0 of the resonator) and
VDDPLL setting.
is greater than the absolute maximum ESR of the resonator
(including ageing, power dissipation, temperature, process
variation or particle contamination).
to (C
maximum ESR is sufficient for both component values), then
choose the component with the highest maximum ESR or choose
an available component between the two listed values.
closest available size to (C
EXTAL–XTAL
Oscillator
= 2*CL – 1pF).
MC68HC912Dx128C Colpitts Oscillator Specification
XTAL–VSS
= 0.82*C
EXTAL–XTAL
13.4.2.4 Key
Technical Data
).
Oscillator
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