OB6561P is an active transition-mode (TM) power
factor correction (PFC) controller for AC-DC switching
mode power supply applications.
OB6561P features an internal start-up timer for standalone
applications, a one quadrant multiplier with THD
optimizer for near unity power factor, zero current
detector (ZCD) to ensure TM operation, a current
sensing comparator with built-in leading-edge blanking,
and a totem pole output ideally suited for driving a
power MOSFET.
OB6561P offers great protection coverage including
system over-voltage protection (OVP) to eliminate
runaway output voltage due to load removal, VCC under
voltage lockout (UVLO), cycle-by-cycle current limiting,
multiplier output clamping that limit maximum peak
switch current, and gate drive output clamping for
external power MOSFET protection.
With added system open loop protection feature,
OB6561P shuts down system when the feedback loop is
open.