The HFC0400 is a fixed-frequency current-mode controller with built-in slope compensation. It targets medium-power, off-line, flyback, switchmode power supplies. At light loads, the controller freezes the peak current and reduces its switching frequency down to 25kHz to offer excellent light-load efficiency. At very light loads, the controller enters burst mode to achieve very low standby power consumption. HFC0400 offers frequency jittering to help dissipate energy generated by conducted noise. HFC0400 also has an X-cap discharge function to discharge the X-cap when the input is unplugged. HFC0400 features multiple protections that include thermal shutdown (TSD), VCC undervoltage lockout (UVLO), overload protection (OLP), over-voltage protection (OVP), and brown-out protection. HFC0400 is available in an SOIC8-7A package.Fixed-frequency current-mode control with built-in slope compensation Frequency foldback down to 25kHz at light loads Burst mode for low standby power consumption Frequency jitter to reduce EMI signature X-cap discharge function Internal high-voltage current source VCC under-voltage lockout with hysteresis (UVLO) Brown-out protection on HV pin Overload protection with programmable delay Thermal shutdown (auto-restart with hysteresis) Latch-off for external over-voltage protection (OVP) and over-temperature protection (OTP) on TIMER pin Short-circuit protection Programmable soft start