Post by thread:Overclocking PIC's

Hi All, I'm currently using a 16C73A-20 in my application running at 20MHz. Besides some pretty demanding calculations, the PIC has to output a 50Hz sinewave chopped by 20KHz on both of it's PWM outputs too. The problem is that unlike the fine tuning in the software, my 50Hz output is at it's best 48,9Hz. Following my calculations I have to use a 20.48MHz Xtal to reach the 50Hz precisely. But this means I have to overclock the PIC with .48MHz. Does anybody have any experiences with overclocking PIC's? Thanks, Daniel...

I haven't had to do that yet - but at the Microchip Seminars I've attended, they mentioned overclocking (IIRC 20 MHz) PICs up to something like 50 MHz, with very good heat sinking - I'd get a 20 MHz part (as you're using), run it at 20.48 MHz, and just plain not worry about it, unless you're in a really warm environment (then maybe clip a small heatsink on the PIC with a dab of thermal grease & call it good.) Mark, spam_OUTmwillisTakeThisOuTnwlink.com D. Schouten wrote: > > Hi All, > > I'm currently using a 16C73A-20 in my application running at 20MHz. Besides so me > pretty demanding calculations, the PIC has to output a 50Hz sinewave chopped b y > 20KHz on both of it's PWM outputs too. The problem is that unlike the fine > tuning in the software, my 50Hz output is at it's best 48,9Hz. Following my > calculations I have to use a 20.48MHz Xtal to reach the 50Hz precisely. But th is > means I have to overclock the PIC with .48MHz. > Does anybody have any experiences with overclocking PIC's? > > Thanks, > > Daniel...

How about using a Scenix SX MCU? It does 50MHz at single instruction cycle! {Quote hidden}> -----Original Message----- > From: pic microcontroller discussion list > [.....PICLISTKILLspam@spam@MITVMA.MIT.EDU]On Behalf Of D. Schouten > Sent: Wednesday, October 21, 1998 11:05 AM > To: PICLISTKILLspamMITVMA.MIT.EDU > Subject: Overclocking PIC's > > > Hi All, > > > I'm currently using a 16C73A-20 in my application running at > 20MHz. Besides some > pretty demanding calculations, the PIC has to output a 50Hz > sinewave chopped by > 20KHz on both of it's PWM outputs too. The problem is that unlike the fine > tuning in the software, my 50Hz output is at it's best 48,9Hz. > Following my > calculations I have to use a 20.48MHz Xtal to reach the 50Hz > precisely. But this > means I have to overclock the PIC with .48MHz. > Does anybody have any experiences with overclocking PIC's? > > Thanks, > > Daniel... >

Hi, I found former that about 20% overclocking won't harm. Imre On Wed, 21 Oct 1998, D. Schouten wrote: > Hi All, > > > I'm currently using a 16C73A-20 in my application running at 20MHz. Besides so me > pretty demanding calculations, the PIC has to output a 50Hz sinewave chopped b y > 20KHz on both of it's PWM outputs too. The problem is that unlike the fine > tuning in the software, my 50Hz output is at it's best 48,9Hz. Following my > calculations I have to use a 20.48MHz Xtal to reach the 50Hz precisely. But th is > means I have to overclock the PIC with .48MHz. > Does anybody have any experiences with overclocking PIC's? > > Thanks, > > Daniel... > >

>Hi All, > > >I'm currently using a 16C73A-20 in my application running at 20MHz. Besides some >pretty demanding calculations, the PIC has to output a 50Hz sinewave chopped by >20KHz on both of it's PWM outputs too. The problem is that unlike the fine >tuning in the software, my 50Hz output is at it's best 48,9Hz. Following my >calculations I have to use a 20.48MHz Xtal to reach the 50Hz precisely. But this >means I have to overclock the PIC with .48MHz. >Does anybody have any experiences with overclocking PIC's? Well, I'm using quite a lot off 16c84-04p at 10Mhz. Works fine at 5v and 21 degrees Celcius.. >Thanks, > >Daniel... Radboud Verberne HAM : PE1RUH