DescriptionThe non-isolated Cuk converter is a DC/DC power converter that, like a buck-boost converter, can produce an output voltage (Vout) magnitude that is either greater or less than the input voltage (Vin) magnitude. However, it is an inverter converter, so the output voltage is of opposite polarity with respect to the input voltage. In the Cuk converter topology, the capacitor C1 acts as the primary means of storing and transferring energy from the input to the output. The advantage of this converter is that both the input current (IL1) and the current feeding the output stage (IL2) are reasonably ripple-free (unlike the buck-boost converter where both these currents are highly discontinuous). Assuming a constant voltage across C1, the theoretical transfer function of the Cuk converter is.
Other type of converters. However the nonlinearity characteristic of the Cuk converter. Cuk converter waveforms (a) Capacitor current. (b) Capacitor ripple.