Typical Application - Harman Kardon MAS 101 Service Manual

Power Factor 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 Start-up Current (10µA Typical)
Low Operating Current (4.5mA Typical)
Feedback Open-Loop Protection
Programmable Maximum On-Time (MOT)
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
Flyback Power Converters with ZCS/ZVS

TYPICAL APPLICATION

VAC
© System General Corp.
Version 1.3.1 (IRO33.0028.B6)
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 start-up current
is lower than 20µA and the operating current is under
4.5mA. The supply voltage can be up to 20V, maximizing
application flexibility.
ZCD COMP INV
VCC GD
SG6961
CS
MOT
GND
www.sg.com.tw • www.fairchildsemi.com
22
Product Specification
SG6961
Vo
September 24, 2007