L6668 is a current-mode primary controller IC, designed to build single-ended converters.
The IC drives the system at fixed frequency at heavy load and an improved Standby function causes a smooth frequency reduction as the load is progressively reduced. At very light load the device enters a special operating mode (burst-mode with fixed, externally programmed peak current) that, in addition to the on-board high-voltage start-up and the very low quiescent current, helps keep low the consumption from the mains and be compliant with energy saving regulations. To allow meeting compliance with these standards in power-factor-corrected systems too, an interface with the PFC controller is provided that enables to turn off the pre-regulator when the load level falls below a threshold.
The IC includes also a programmable soft-start, slope compensation for stable operation at duty cycles greater then 50%, a disable function, a leading edge blanking on current sense to improve noise immunity, latched disable for OVP or OTP shutdown and an effective two-level OCP able to protect the system even in case the secondary diode fails short.
- LATCHED DISABLE FOR OVP/OTP FUNCTION
- DISABLE FUNCTION (ON/OFF CONTROL)
- 2% PRECISION REFERENCE VOLTAGE EXTERNALLY AVAILABLE
- PROGRAMMABLE SOFT-START
- BLUE ANGEL, ENERGY STAR, EU CODE OF CONDUCT COMPLIANT
- ±800 mA TOTEM POLE GATE DRIVER WITH INTERNAL CLAMP AND UVLO PULL-DOWN
- SO16 PACKAGE ECOPACK®
- PULSE-BY-PULSE & HICCUP-MODE OCP
- SLOPE COMPENSATION
- MULTIPOWER BCD TECHNOLOGY
- ON-BOARD HIGH-VOLTAGE START-UP
- LOAD-DEPENDENT CURRENT-MODE CONTROL: FIXED-FREQUENCY (HEAVY LOAD), FREQUENCY FOLDBACK (LIGHT LOAD), BURST-MODE (NO-LOAD)
- LOW QUIESCENT CURRENT (< 2 mA)
- INTERFACE WITH PFC CONTROLLER
- IMPROVED STANDBY FUNCTION
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