By Chupa -
- Wed Jun 20, 2007 8:26 pm #31637
im using a PIC18F2550 in a project with a 20Mhz crystal and a 32KHz watch crystal on timer1. the osc pins and timer1 are right next to each other and the dat sheet recommends a ground ring around the crystals (page 134)
The Timer1 oscillator circuit draws very little powerI am fairly new with Eagle cad, just mainly going by the tutorials posted here a couple weeks ago. I was wondering if someone could explain how to do this with Eagle, or where to see more information on doing this.
during operation. Due to the low-power nature of the
oscillator, it may also be sensitive to rapidly changing
signals in close proximity.
The oscillator circuit, shown in Figure 12-3, should be
located as close as possible to the microcontroller.There should be no circuits passing within the oscillator
circuit boundaries other than VSS or VDD.
If a high-speed circuit must be located near the oscillator
(such as the CCP1 pin in Output Compare or PWM
mode, or the primary oscillator using the OSC2 pin), a
grounded guard ring around the oscillator circuit, as
shown in Figure 12-4, may be helpful when used on a
single-sided PCB or in addition to a ground plane.
image from the page:
Paul "Chupa" Mac