The HFC0511 is a fixed-frequency, current-mode controller with internal slope compensation specifically designed for medium-power, offline, flyback, switch-mode power supplies. The HFC0511 is a highly efficient green-mode controller. At light loads, the controller freezes the peak current and reduces its switching frequency down to 27kHz to achieve excellent light-load efficiency. At very light loads, the controller enters burst mode to achieve very low standby power consumption. The HFC0511 offers frequency jittering to help dissipate energy generated by the conducted noise. The HFC0511 employs an over-power compensation function to narrow the difference of the over-power protection point between the low line and high line. The HFC0511 also has an X-cap discharge function to discharge the X-capacitor when the input is unplugged. This helps lower the power at no load. Full protection features include thermal shutdown, VCC under-voltage lockout (UVLO), overload protection (OLP), over-voltage protection (OVP), and brown-out protection. The HFC0511 is available in a SOIC8-7A package.