L4985 Datasheet CCM PFC controller with high voltage startup Features Peak current mode CCM-operated 800 V high voltage startup with integrated input voltage sensing Active input filter capacitor discharge Proprietary multiplier emulator with minimum THD of line current in all operating conditions (CCM and DCM) Extremely few external components Protections: feedback loop failure, OVP, OCP, inductor saturation, brown-in, brownout (compliant to medical SMPS standards) Inductor current sense Disable and low consumption function In-rush current monitoring Soft-start for smooth startup 1.2% ( Tj = 25 C) internal reference voltage 65 kHz (A version) and 130 kHz (B version) switching frequency SO8 package Application PFC pre-regulators for: IEC61000-3-2 and JEIDA-MITI compliant SMPS in excess of 1 kW Desktop PC, server, web server, game console Product status link High power LED luminaries L4985 Industrial and medical SMPS according to IEC 60601-1-2 L4985A L4985B Description L4985ATR The L4985 is a peak current-mode PFC controller for boost converter with a proprietary multiplier emulator which in addition to the innovative THD optimizers L4985BTR guarantee very low Total Harmonic Distortion (THD) performance in all operating conditions. The device comes in a pin SO package and offers a high performance/ Product summary low-component count solution for CCM-operated boost PFC pre-regulators in Order EN61000-3-2 and JEIDA-MITI compliant applications, in a power range that spans Package Packaging codes from few hundred W to some kW. L4985A Tube The device, thanks to a proprietary off-time modulator, operates in quasi-fixed frequency in all operating conditions. Two options are available, 65 kHz for A and L4985B Tube 130 kHz for B. Tape and SO-8 L4985ATR The 800V high voltage start-up block includes also the circuitry to discharge the reel X-capacitors of the EMI filter to a safe level. This allows the unit to meet safety Tape and regulation (such as IEC 61010-1 or IEC 62368-1) without using the traditional L4985BTR reel discharge resistor in parallel to the X-capacitors. The device features low consumption and disable functions allowing usage in applications supposed to comply even with the latest energy saving requirements issued by Energy Star, the Department of Energy (DoE) in the United States, the European Code of Conduct, the European Unions Ecodesign Directive, and other guidelines. DS13769 - Rev 2 - August 2021 www.st.com For further information contact your local STMicroelectronics sales office.L4985 In addition to an overvoltage protection able to keep the output voltage under Product label control during transient conditions, the IC is provided also with a protection against feedback loop failures or erroneous settings and boost inductor saturation. The brownout protection function allows to design medical equipment according to the latest regulations driven by IEC 60601-1-2 which requires the output regulation in case of mains dips lasting up to 500 msec. Soft-start limits the peak current. The totem-pole output stage, capable of 0.7 A source and 1.5 A sink current, is suitable for big MOSFET or IGBT drives. DS13769 - Rev 2 page 2/27