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

– High power LED luminaries

Description

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

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/

low-component count solution for CCM-operated boost PFC pre-regulators in

EN61000-3-2 and JEIDA-MITI compliant applications, in a power range that spans

from few hundred W to some kW.

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

130 kHz for B.

The 800V high voltage start-up block includes also the circuitry to discharge the

X-capacitors of the EMI filter to a safe level. This allows the unit to meet safety

regulation (such as IEC 61010-1 or IEC 62368-1) without using the traditional

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 Union’s Ecodesign Directive, and other

guidelines.

– Industrial and medical SMPS according to IEC 60601-1-2