Continuous conduction mode (CCM) PFC controller with high voltage startup
In addition to its embedded control functions, the L4985 offers an innovative THD optimizers guarantee very low Total Harmonic Distortion (THD) performance in all operating conditions. A high-performance solution for CCM-operated boost PFC pre-regulators, the L4985 ensures a low component count as it already embeds the high-voltage start-up circuit and the X-cap discharge circuits.
Key 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, brown-out (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 examples
EN61000-3-2 and JEIDA-MITI compliant applications 
Desktop PC, server, web server, game console 
High power LED luminaries 
Industrial and medical SMPS Recommended resources
Tailored for AC/DC adapters with wide input mains range, very low power consumption at light load and good average efficiency, the EVL400W-80PL is a low-component count solution for boost PFC pre-regulators in applications required to meet the most stringent efficiency and standby regulations.
Suitable for all SMPS from 150 W to several kW which must comply with IEC61000-3-2 and JEITA-MITI standards, the feature-rich EVL4985-350W evaluation board is a cost-effective solution as the number of external components required is limited as the embedded L4985 includes the high-voltage start-up circuit and the X-cap discharge circuits.
