Post by thread:RC 4MHz clock

On Mon, 15 Nov 1999, Graham North wrote: > I am wanting to use an RC oscillator on a 16F84 circuit. > > Can anyone tell me what values to use (R and C) for an approx 4 MHz clock. From the databook: R=4.7K, C=22pF Fosc is only approximate and will drift a bit with temperature. /**/

Graham North wrote: > > I am wanting to use an RC oscillator on a 16F84 circuit. > > Can anyone tell me what values to use (R and C) for an approx 4 MHz clock. 4K7 (That's 4.7K) and 22pf for ~4Mhz Don McKenzie spam_OUTdonTakeThisOuTdontronics.com http://www.dontronics.com Don's Download Dungeon: http://www.dontronics.com/download.html World's Largest Range of Atmel and PICmicro Hardware and Software

Cext Rext AverageFosc @ 5V, 25¡C (PDIP) 20 pF 3.3k 4.68 MHz ± 27% 20 pF 5.1k 3.94 MHz ± 25% According to page 77 of microchip's 30445B.PDF. It also covers min. max. RC values, temp. variation, and more. Only 691 K from http://www.microchip.com For stability: 20pF is a good minimum capacitance, 3k minimum R, and 100k is maximum. </David_V> ----- Original Message ----- From: Graham North <.....graham.northKILLspam@spam@LANDINST.COM> To: <PICLISTKILLspamMITVMA.MIT.EDU> Sent: Tuesday, November 16, 1999 3:16 AM Subject: RC 4MHz clock > I am wanting to use an RC oscillator on a 16F84 circuit. > > Can anyone tell me what values to use (R and C) for an approx 4 MHz clock. >