Datasheet

PIC16C77X
DS30275B-page 130 Advance Information  1999-2013 Microchip Technology Inc.
12.2.3 RC OSCILLATOR
For timing insensitive applications the “RC” device
option offers additional cost savings. The RC oscillator
frequency is a function of the supply voltage, the resis-
tor (R
EXT) and capacitor (CEXT) values, and the operat-
ing temperature. In addition to this, the oscillator
frequency will vary from unit to unit due to normal pro-
cess parameter variation. Furthermore, the difference
in lead frame capacitance between package types will
also affect the oscillation frequency, especially for low
C
EXT values. These factors and the variation due to tol-
erances of external R and C components used need to
be taken into account for each application. Figure 12-4
shows how the R/C combination is connected to the
PIC16C77X.
FIGURE 12-4: RC OSCILLATOR MODE
OSC2/CLKOUT
Cext
Rext
PIC16C77X
OSC1
Fosc/4
Internal
clock
VDD
VSS
774.book Page 130 Tuesday, January 29, 2013 12:02 PM