MC912D60ACPVE8 Datasheet, PDF (191/460 Pages) Freescale Semiconductor, Inc – MC68HC912D60A MC68HC912D60C MC68HC912D60P Technical Data

Oscillator
MC68HC912D60C Colpitts Oscillator Specification
12.4.4 MC68HC912D60C DC Blocking Capacitor Guidelines
Due to the placement of the resonator from EXTAL to VSS and the
nature of the microcontroller’s inputs, there will be a DC bias voltage of
approximately (VDD–2V) across the pins of the resonator. For some
resonators, this can have long-term reliability issues. To remedy this
situation, a DC-blocking capacitor can be placed in series with the
crystal, as shown in Figure 12-3.
The value of the DC-blocking capacitor should be between 0.1 and
10nF, with a preferred value of 1nF. This capacitor must be connected
as shown in Figure 12-3. If connected thus, all other oscillator
specifications and guidelines continue to apply.
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor
Oscillator
Technical Data
191