控制器與高壓MOSFET簡化設計非隔離開關

　　有許多應用在離線開關采用交流電源供電的需要小包裝或必須占用系統(tǒng)主板空間小。這些可以從“總是”智能電表用于家庭自動化，能源消費監(jiān)測家用電器，低成本離線LED驅(qū)動器在照明應用與高功率因數(shù)，以滿足國際要求的總諧波失真（THD），EMC和安全性。

　　更高的效率和輸出電流能力的兩個設備制造商遷移到交換機的更令人信服的理由。這些好處將有助于原始設備制造商滿足監(jiān)管要求降低功耗，同時滿足更大的電流需求。然而，其他開關的優(yōu)點，如更小的尺寸，更寬的輸入電壓范圍，和故障保護，以及顯著。

　　Makers of such integrated controllers with built-in high-voltage MOSFETs for non-isolated low-power AC/DC conversion applications include power semiconductor manufacturers like Texas Instruments， Power Integrations， STMicroelectronics， Fairchild Semiconductor， and ON Semiconductor among others. TI recently unveiled an integrated controller UCC28880 for these applications. It integrates a pulse-width-modulated （PWM） controller and a 700 V MOSFET， as well as a high-voltage current source on a single chip， enabling start-up and operation directly from the rectified mains voltage （Figure 1）。 Plus， as shown in Figure 1， it includes a 5 V regulator and protection functions like a current limiter， over-temperature protection， under-voltage lockout （UVLO）， and overload protection for short circuit at the output.