Simple CCO Using CCIIs and S-R Latch and Its Application

A simple circuit technique to realize current controlled oscillator (CCO) with two low-impedance input terminals is presented. By suitably setting two input signals, the linear frequency-current relation of the proposed CCO can be either positive or negative slope in the same circuit configuration. The oscillating output frequency proportional to the difference between two input currents can be also obtained. The realization method is employed second-generation current conveyors and set-reset latch. Experimental results verifying performances of the proposed CCO are in close agreement with expected values. To demonstrate the usefulness of the proposed oscillator, application example in current-mode variable frequency control for buck converter is included.