L4984

L4984 CCM PFC controller Features ■ Line-modulated fixed-off-time (LM-FOT) control of CCM-operated PFC pre-regulators ■ Proprietary LM-FOT modulator for nearly fixedfrequency operation ■ Proprietary multiplier design for minimum THD of AC input current ■ Fast “bi-directional” input voltage feedforward (1/V2 correction) ■ Accurate adjustable output overvoltage protection ■ Protection against feedback loop failure (latched shutdown) ■ Inductor saturation protection ■ AC brownout detection ■ Digital leading-edge blanking on current sense ■ Soft-start ■ 1% (at Tj = 25 °C) internal reference voltage ■ - 600 / + 800 mA totem pole gate driver with active pull-down during UVLO and voltage clamp ■ SSOP10 package Applications ■ PFC pre-regulators for: – IEC61000-3-2 and JEIDA-MITI compliant SMPS in excess of 1 KW – Desktop PC, server, web server Datasheet — preliminary data SSOP10 Table 1. Device summary Order code Package L4984D L4984DTR SSOP10 Packaging Tube Tape and reel August 2012 Doc ID 023489 Rev 1 This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice. www.bdtic.com/ST 1/35 www.st.com 35 Contents Contents L4984 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Electrical characteristics . . . . . . . . . ...