The HF500A-30 is a fixed-frequency, current mode regulator with built-in slope compensation. The device integrates a 700V MOSFET and a full-featured controller into one chip for a low-power, offline, flyback, switch-mode power supply with EMI optimization.
While under medium or heavy loads, the regulator operates at a fixed frequency with frequency jittering. Frequency jittering reduces EMI energy on the switching frequency (fSW) and its harmonics. Under light-load conditions, the regulator holds the peak current and reduces fSW to 25kHz to offer excellent efficiency. At very light loads, the regulator enters burst mode to achieve low standby power consumption.
Full protection features include brown-in and brownout, VCC under-voltage lockout (UVLO) protection, overload protection (OLP), short-circuit protection (SCP), VCC over-voltage protection (OVP), input OVP, and over-temperature protection (OTP). The HF500A-30 features over-power line compensation to ensure that the overload protection point is independent of the input voltage (VIN). The HF500A-30 is available in a PDIP8-7B package.