代理產線

SG6902

 2007-04-11

【基本資料】

【產品特性】

‧Green-mode PFC and PWM operation
‧No switching of PFC at light loads for the best power saving
‧Low start-up and operating current
‧Innovative Switching-Charge multiplier-divider
‧Multi-vector control for improved PFC output transient response
‧Interleaved PFC/PWM switching
‧Programmable two-level PFC output voltage
‧Average-current-mode control for PFC
‧Cycle-by-cycle current limiting for PFC/PWM
‧PFC over-voltage and under-voltage protections
‧PFC and PWM feedback open-loop protection
‧Brownout protection
‧Over-temperature protection
‧SG6902SZ 20-Pin SOP (Lead Free)
‧SG6902RZ 20-Pin SSOP(Lead Free)

【產品應用】

‧Switching Power Suppliers with Active PFC
‧High-Power Adaptors

【文字介紹】

The highly integrated SG6902 is specially designed for power supplies consist of boost PFC and Flyback PWM. It requires very few external components to achieve green-mode operation and versatile protections. It is available in 20-pin SOP and SSOP packages.
The patented interleave-switching feature synchronizes the PFC and PWM stages and reduces switching noise. At light loads, the switching frequency is continuously decreased to reduce power consumption. If output loading is further reduced, the PFC stage is turned off to further 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, the SG6902 will shut off PFC to prevent extra-high voltage on output. Programmable two-level output voltage control will reduce the PFC output voltage at low line input to increase the efficiency of the power supply.
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, SG6902 provides complete protection functions such as brownout protection and RI pin open/short protections.