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.