Discontinuous Current Mode
Discontinuous Current Mode , discontinuous conduction mode (DCM for short, as "non-continuous current flow"), continuous mode or discontinuous current operation is a term used in power electronics. It means that the current in the storage choke drops to zero within one switching cycle .
advantages
- only switching losses when switching off
disadvantage
- Every time the current in the coil becomes zero ( commutation ), a damped oscillation (ringing) is excited in the resonant circuit , which results from the coil inductance and the parasitic capacitances (coil, diode, transistor). These vibrations cause interference emissions and can possibly even damage or destroy the circuit.
- Since the relationship between duty cycle and output voltage is non-linear, a small signal analysis (AC analysis) is not easily possible during the design . The stability check is therefore difficult.