1FEATURES

• Buck Power Factor Correction for High

Efficiency Across Line

• Low Off-Line Startup Current, With SmartStart

Algorithm for Fast Startup With Soft-Start

• Compatible With Resistive or Pass Transistor

Fed Startup from the AC Line

• Low Power SmartBurst Mode for Standby and

Light-Load Conditions

• Current Sense Inputs for PFC control and

Overload Protection

• Line Sense UVLO

• Sense and Drive Control for External Startup

Depletion Mode FET

• Latching Fault Input Pin

APPLICATIONS

• High Efficiency AC-DC Adapters

• Low Profile and High Density Adapters

DESCRIPTION

The UCC29910A Buck Power Factor Correction

(PFC) controller provides a relatively flat

high-efficiency performance across universal line for

designers requiring a high power factor (>0.9) and

wishing to meet the requirements of IEC 61000-3-2.

Based on a buck topology, inherent inrush current

limiting eliminates the need for additional

components. With a typical bus voltage of 84 V, the

topology is ideally suited for use with low voltage

stress downstream regulation/isolation power trains,

such as half-bridge stages controlled by the

UCC29900, (Texas Instruments Literature Number,

SLUS923). This combination offers low

common-mode noise generation allowing reduced filtering and exceptionally high conversion efficiency.

The UCC29910A incorporates AC line UVLO and

controlled soft start for fast start-up. Enhanced

light-load efficiency is achieved through advanced

management algorithms for best-in-class no-load and

light-load performance.