SG6980 Datasheet, PDF (1/18 Pages) Fairchild Semiconductor – Single-Stage PFC Controller

Single-Stage PFC Controller
FEATURES OVERVIEW
„ Innovative switching-charge multiplier divider
„ Multi-vector control for improved PFC output
transient response
„ 1:1 Synchronous switching with SYNC
„ Average current mode control
„ Remote on/off control
„ Power-on sequence control
„ Programmable PFC output-voltage control
„ Cycle-by-cycle current limiting
„ Over-voltage and under-voltage protections
„ Brownout and open-loop protections
„ Low start-up and operating current
APPLICATIONS
„ Active-PFC switching power supplies
„ TV and home appliances
„ Computer and telecom
Product Specification
SG6980
DESCRIPTION
The highly integrated SG6980 is designed for power
supplies with boost power-factor-correction (PFC).
It requires very few external components to achieve
desirable operation and includes versatile protections /
compensation. It is available in 16-pin DIP and SOP
packages. The innovative switching-charge multiplier
divider enhances the PFC circuit’s noise immunity. The
proprietary multi-vector control scheme provides a fast
transient response in a low-bandwidth PFC loop, in which
the overshoot and undershoot of the PFC voltage are
clamped. If the feedback loop is broken, SG6980 shuts off
to prevent extra-high voltage on output. The PFC gate
driver can be synchronized with external SYNC signal
and the switching noise can be reduced. During start-up,
the RDY (ready) is pulled low until the PFC output
voltage reaches the setting level. This signal can be used
to control the second forward stage for proper power-on
sequence. In addition, SG6980 provides complete
protection functions, such as brownout and RI open/short.
TYPICAL APPLICATION
SG6980
© System General Corp.
Version 1.0.1 (IAO33.0064.B0)
-1-
www.sg.com.tw • www.fairchildsemi.com
September 17, 2007