SG6932_08 Datasheet, PDF (1/20 Pages) Fairchild Semiconductor – PFC / Forward PWM Controller

May 2008
SG6932
PFC / Forward PWM Controller
Features
ƒ Interleaved PFC/PWM Switching
ƒ Low Operating Current
ƒ Innovative Switching-Charge Multiplier-divider
ƒ Multi-vector Control for Improved PFC Output
Transient Response
ƒ Average Current Mode for Input-current Shaping
ƒ PFC Over-voltage and Under-voltage Protections
ƒ PFC and PWM Feedback Open-loop Protection
ƒ Cycle-by-cycle Current Limiting for PFC/PWM
ƒ Slope Compensation for PWM
ƒ Selectable PWM Maximum Duty Cycle: 50%, 65%
ƒ Brownout Protection
ƒ Power-on Sequence Control and Soft-start
Applications
ƒ Switch-mode Power Supplies with Active PFC
ƒ Servo-system Power Supplies
ƒ PC-ATX Power Supplies
Description
The highly integrated SG6932 is designed for power
supplies with boost PFC and forward PWM. It requires
very few external components to achieve versatile
protections and compensation. It is available in 16-pin
DIP and SOP packages.
The proprietary interleave-switching feature
synchronizes the PFC and PWM stages and reduces
switching noise. At light load, the switching frequency is
continuously decreased to reduce power consumption.
For PFC stage, 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, SG6932 shuts off to prevent
extra-high voltage on output.
For the forward PWM stage, the synchronized slope
compensation ensures the stability of the current loop
under continuous-conduction-mode (CCM) operation.
Hiccup operation during output overloading is
guaranteed. The soft-start and programmable maximum
duty cycle ensure safe operation.
SG6932 provides complete protection functions, such
as brownout protection and RI open/short latch off.
Ordering Information
Part
Number
SG6932DZ
SG6932SZ
Operating Temperature
Range
Package
-40°C to +85°C
16-pin Dual In-Line Package (DIP)
-40°C to +85°C
16-pin Small Outline Package (SOP)
Packing
Eco Status _Method
RoHS
Tube
RoHS
Tape & Reel
For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2007 Fairchild Semiconductor Corporation
SG6932 • Rev. 1.1.3
www.fairchildsemi.com