##### 12.3 IMPROVING SWEEP LINEARITY

A simple exponential sweep generator shown in Fig. 12.9(a) essentially produces a non-linear sweep voltage, unless *τ* >> *T*_{S} or *V* >>*V*_{s}. In an exponential sweep generator, since the capacitor charges exponentially, the resultant sweep so generated is non-linear. To get a linear sweep, the capacitor is required to charge with a constant current. Let us consider the methods of linearizing an exponential sweep. Introduce an auxiliary generator, *v*, as shown in Fig. 12.9(b). If *v* is always kept equal to the voltage across *C*(i.e.,*v* = *v*_{C}), as the polarities of *v* and *v*_{C} are opposite, the net voltage in the loop is *V*. Then *i* = *V /R* which is a constant. That means, the capacitor charging current is constant and perfect linearity ...