Offline Power Factor Correction (PFC) Controllers

Analog Devices’ family of offline power factor correction (PFC) controllers provide a power factor of up to 0.99 by actively modulating AC mains input current to comply with most harmonic current emission requirements. Many of these devices operate from an input voltage of 90 VAC to 265 VAC and produce a 400 VDC output, which typically powers an isolated downstream DC/DC converter. Some of these offline PFC controllers drive an external transformer, like the LT3798, which provides a combination of PFC, isolation, and regulated secondary voltage. Other offline PFC controllers, like the ADP1048W, provide signals that are converted into the digital domain to provide maximum flexibility, with key parameters reported and adjusted via a PMBus™ interface.