HF500-40

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

Datasheet

Description

The HF500-40 is a fixed-frequency, current-mode regulator with built-in slope compensation. The HF500-40 combines a 700V MOSFET and a full-featured controller into one chip for a low-power, offline, flyback, switch-mode power supply.

At medium and heavy loads, the regulator works in a fixed frequency with frequency jittering. Jittering helps reduce EMI energy on the switching frequency and its harmonics. During light-load condition, the regulator freezes the peak current and reduces its switching frequency 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 brown-out, VCC under-voltage lockout (UVLO), overload protection (OLP), short-circuit protection (SCP), input over-voltage protection (OVP), VCC over-voltage protection (OVP), and over-temperature protection (OTP).

The HF500-40 features over-power line compensation to ensure that the overload protection point is independent of the input voltage.

The HF500-40 is available in a PDIP8-7B package.

Advantages Include:

Fully featured controller in one chip for a low-power, offline, flyback, switch-mode power supply
Multi-mode control during different load conditions
Over-power line compensation and full suite of protection features

Features & Benefits

700V/1Ω Integrated MOSFET
Fixed-Frequency, Current-Mode Control Operation with Built-In Slope Compensation
Frequency Foldback Down to 25kHz at Light Load
Burst Mode for Low Standby Power Consumption
Frequency Jittering for a Reduced EMI Signature
Over-Power Compensation
Internal High-Voltage Current Source
VCC Under-Voltage Lockout (UVLO) with Hysteresis
Programmable Input B/O and Over-Voltage Protection (OVP)
VCC Over-Voltage Protection (OVP)
Overload Protection (OLP) with Programmable Delay
Latch-Off Protection on TIMER
Over-Temperature Protection (OTP) (Auto-Restart with Hysteresis)
Short-Circuit Protection (SCP)
Programmable Soft Start (SS)
Available in a PDIP8-7B Package