Control circuit for power converter and related control method

• Main Authors: JAN CHUEH-KUEI, HUANG WEI-JEN, LIN SHUI-MU, HUANG TSUNG-WEI
• Format: Patent
• Language: English
• Published: 20.10.2015
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONTROLLING; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; PHYSICS; REGULATING; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

A control circuit of a power converter includes: a zero current detection circuit for detecting a current flowing between an inductor and a voltage output terminal of the power converter to generate a zero current detection signal; an adjusting circuit for generating an adjustment signal according to the zero current detection signal; a clock signal generating circuit for adjusting a frequency of a clock signal according to the adjustment signal; a periodical signal generating circuit for generating a periodical signal according to the clock signal; an error detection circuit for generating an error signal; and a control signal generating circuit for generating a control signal to control operations of a power switch. If the and amount of pulses generated by the zero current detection circuit satisfy a predetermined condition, the adjusting circuit switches the power converter's operation mode from DCM to CCM.