HF500A-30

Fixed-Frequency, EMI-Optimized Flyback Regulator with Multi-Mode Control and Over-Power Line Compensation

Description

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 (f_SW) and its harmonics. Under light-load conditions, the regulator holds the peak current and reduces f_SW 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, V_CC under-voltage lockout (UVLO) protection, overload protection (OLP), short-circuit protection (SCP), V_CC 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 (V_IN). The HF500A-30 is available in a PDIP8-7B package.

Features & Benefits

700V/1.4Ω Integrated MOSFET
Fixed-Frequency, Current-Mode Control Operation with Integrated Slope Compensation
EMI (Radiated Emissions) Optimization
Frequency Foldback Down to 25kHz under Light Load Conditions
Burst Mode for Low Standby Power Consumption
Frequency Jittering for EMI Signature Reduction
Over-Power Compensation
Internal High-Voltage Current Source
V_CC Under-Voltage Lockout (UVLO) Protection with Hysteresis
Configurable Input B/O and Over-Voltage Protection (OVP)
V_CC Over-Voltage Protection (OVP)
Overload Protection (OLP) with Configurable Delay
Latch-Off Protection On Timer
Over-Temperature Protection (OTP) (Auto-Restart with Hysteresis)
Short-Circuit Protection (SCP)
Configurable Soft Start (SS)
Available in a PDIP8-7B Package