Offline Switchers Come in Tiny Packages

　　Offline Switchers Come in Tiny Packages

　　當(dāng)工程師考慮離線開關(guān)從電信和數(shù)據(jù)通信設(shè)備，個(gè)人電腦和工業(yè)電源系統(tǒng)，他們主要認(rèn)為笨重的交流/直流前端解決方案的形式多種多樣，如磚，模塊，和開放的框架。然而，有許多應(yīng)用在離線開關(guān)由交流電源供電的需要小包裝或必須占用主板上的一個(gè)小空間。一些例子：USB適配器電源媒體播放器、電子閱讀器和GPS設(shè)備；低成本的、離線LED驅(qū)動(dòng)器照明應(yīng)用的高功率因數(shù)達(dá)到國(guó)際總諧波失真（THD）要求，電磁兼容，安全。離線開關(guān)也被用來作為在PC和筆記本電腦的備用電源，以及在智能手機(jī)和其他移動(dòng)設(shè)備小巧的充電器。關(guān)鍵是有許多應(yīng)用在離線AC / DC開關(guān)是在小的形式因素的需要。

　　本文將探討從崔公司飛宏美國(guó)，推薦的電源解決方案，和XP的電源。除了脫落一些輕的緊湊的離線開關(guān)的性能，它還將確定關(guān)鍵特征和提供給工程師具體產(chǎn)品的好處。

　　Compact external switchers

　　CUI， Inc.， for instance， has readied an ultra-compact 5 W wall-plug adapter with integrated USB connector （Figure 1）， the EPSA050100U-I38-EJ. With a footprint of just 1.61 x 1.18 in. （41 x 30 mm）， the adapter is among the industry’s smallest AC/DC power supply to integrate USB connection， making it suitable for small mobile devices. In addition， it offers level V energy-efficiency compliance for green design requirements with a no-load power draw of less than 0.1 W. Rated for an output of 5 VDC at 1 A， the high-density EPSA050100U-I38-EJ operates at AC input voltages ranging from 90 to 264 VAC. Safety marks include UL/cUL， PSE， and LPS （limited power source）。 What is more， the external adapter also meets EN55022 Class B limits for conducted and radiated EMI and provides protection for overvoltage， overcurrent， and short-circuit conditions.