POWER FACTOR CORRECTION CONTROLLER OF CRITICAL DUCTING

DESCRIPTION

The SA7527 provides simple and high performance active power factor correction. The SA7527 is optimized for electronic ballasts and low power and high-density power supplies which require minimum board size, reduced external components and low power dissipation.

Because the R/C filter is included in the current sense block, the external R/C filter is not necessary. Special circuitry has also been added to prevent no load runaway conditions. Regardless of the supply voltage, the output drive clamping circuit limits the overshoot of the power MOSFET gate drive. It greatly enhances the system reliability.

FEATURES

* Internal start-up timer

* Internal R/C filter eliminates the need for an external R/C filter

* Very precise adjustable output over voltage protection

* Zero current detector

* One quadrant multiplier

* Trimmed 1.5 internal band gap reference

* Under voltage lockout with 3V of hysteresis

* Totem pole output with high state clamp

* Low start-up and operating current

* 8-pin DIP or 8-pin SOP

APPLICATIONS

* Electronic ballast

* SMPS