SG6901 Datasheet, PDF (1/19 Pages) Fairchild Semiconductor – CCM PFC/Flyback PWM Combination Controller

February 2009
SG6901A
CCM PFC/Flyback PWM Combination Controller
Features
ƒ Interleaved PFC/PWM Switching
ƒ Low Startup and Operating Current
ƒ Innovative Switching Charge Multiplier Divider
ƒ Multi-vector Control for Improved PFC Output
Transient Response
ƒ Average-Current-Mode Control for PFC
ƒ Programmable Two-Level PFC Output 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 H/L Line Over-Power Compensation for PWM
ƒ Brownout Protection
ƒ Over-Temperature Protection (OTP)
Applications
ƒ Switching Power Supplies with Active PFC and
Standby Power
ƒ High-Power Adaptors
Description
The highly integrated SG6901A is designed for power
supplies with boost PFC and flyback PWM. It requires
very few external components to achieve versatile
protections. It is available in a 20-pin SOP package.
A proprietary interleave-switching feature synchronizes
the PFC and PWM stages and reduces switching noise.
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, the SG6901A shuts off PFC to
prevent extra-high voltage on output.
For the flyback PWM, the synchronized slope
compensation ensures the stability of the current loop
under continuous-conduction-mode operation. Built-in
line-voltage compensation maintains constant output-
power limit. Hiccup operation during output overloading
is also guaranteed.
In addition, SG6901A provides protection functions,
such as brownout and RI pin open/short protection.
Ordering Information
Part Number
Operating
Temperature Range
Eco
Status
SG6901ASZ
-30°C to +85°C
RoHS
Package
20-Lead, Small Outline Integrated
Circuit (SOIC), JEDEC
MS013, .300 inch, Wide Body
Packing
Method
Tape & Reel
For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
SG6901A • Rev. 1.0.2
www.fairchildsemi.com