3-38
Figure 3-43A.—Relationship of R and C to linearity.
Figure 3-43B.—Relationship of R and C to linearity.
Decreasing the value of the TC (R2 or C2), as shown in figure 3-43, view (B), results in an increase
in the number of time constants and therefore causes linearity to decrease. Anytime the number of time
constants increases, the percentage of charge increases (see the Universal Time Constant Chart, figure 3-
39), and amplitude (physical length) increases. Without an increase in gate length, the time that C2 is
allowed to charge through R2 remains the same; therefore, electrical length remains the same. Linearity is
affected by gate length, the value of R, and the value of C; but is not affected by changing the value of
VCC. Increasing the gate length decreases linearity, and decreasing gate length increases linearity.
Increasing R or C in the circuit increases linearity, and decreasing R or C in the circuit decreases linearity.
The entire time of the sawtooth, from the time at which the capacitor begins charging (T0 in figure
3-41, view (B)) to the time when it starts charging again (T2), is known as the prt of the wave. The pulse
repetition frequency of the sawtooth wave is:
