June 2010
?2008 Fairchild Semiconductor Corporation
www.fairchildsemi.com
SG6961 " Rev. 1.3.2
SG6961
Critical Conduction Mode PFC Controller
Features
   Boundary Mode PFC Controller
   Low Input Current THD
   Controlled On-Time PWM
   Zero-Current Detection
   Cycle-by-cycle Current Limiting
   Leading-Edge Blanking Instead of RC Filtering
   Low Startup Current: 10?/SPAN>A (Typical)
   Low Operating Current: 4.5mA (Typical)
   Feedback Open-Loop Protection
   Programmable Maximum On-Time
   Output Over-Voltage Clamping Protection
   Clamped Gate Output Voltage 16.5V
Applications
   Electric Lamp Ballasts
   AC-DC Switching Mode Power Converter
   Open-Frame Power Supplies and Power Adapters
Description
The SG6961 is an 8-pin boundary mode PFC controller
IC intended for controlling PFC pre-regulators. The
SG6961 provides a controlled on-time to regulate the
output DC voltage and achieve natural power factor
correction. The maximum on-time of the external switch
is programmable to ensure safe operation during AC
brownouts. An innovative multi-vector error amplifier is
built in to provide rapid transient response and precise
output voltage clamping. A built-in circuit disables the
controller if the output feedback loop is opened. The
startup current is lower than 20礎 and the operating
current is under 4.5mA. The supply voltage can be up to
20V, maximizing application flexibility.
Ordering Information
Part Number
Operating
Temperature Range
Package
Packing Method
SG6961SZ
-30癈 to +85癈
8-Pin Small Outline Package (SOP)
Tape & Reel
SG6961DZ
-30癈 to +85癈
8-Pin Dual Inline Package (DIP)
Tube
SG6961SY
-30癈 to +85癈
8-Pin Small Outline Package (SOP)
Tape & Reel