STMicroelectronics’ L4984D is a current-mode PFC controller which offers a low-cost solution for boost PFC pre-regulators in applications which require compliance with the IEC 61000-3-2 and JEIDA-MITI standards, and which supply power in a range from a few hundred Watts to more than 1kW.
The L4984D implements ST’s proprietary line-modulated fixed-off-time control scheme which allows fixed-frequency operation in boost PFC converters as long as they are operated in continuous-conduction mode.
The highly linear multiplier includes a special circuit which is able to reduce the crossover distortion of the AC input current. This enables the device to operate over a wide mains-voltage range while maintaining a reasonably low figure for total harmonic distortion, even over a wide range of load values.
The output voltage is controlled by means of a voltage-mode error amplifier and an accurate internal voltage reference. Loop stability is optimised by the voltage feed-forward function, which also markedly improves transient response in the case of mains drops and surges.
The IC is provided with protection against feedback-loop failures or erroneous settings.
- Energy-efficient power supplies that must comply with Blue Angel, ENERGY STAR® or Energy 2000
- Web servers
- Adjustable output over-voltage protection
- Inductor saturation protection
- AC brown-out detection
- Digital leading-edge blanking on current sense
- Disable function for remote turn-on/turn-off
Orderable Part Number: EVL4984-350W