The circuit in Figure 1 converts a regulated 5V input to an isolated 5V output with 1A current-output capability. IC1, a push-pull transformer driver, powers a pair of cross-coupled power MOSFETs in a flip-flop-like configuration. In turn, the MOSFETs toggle the primary winding of a forward transformer. The transformer's secondary output, after rectification and filtering, provides the isolated 5V supply. Because the output voltage is unregulated, its voltage tolerance depends on the input-voltage range and the range of load current. With Schottky rectifiers, such as the MBRS130 for D1 and D2, the circuit delivers 5V ±10% at 700 to 1000mA from a 5V ±5% input with 80% efficiency (Figure 2). Using ultrafast-recovery silicon rectifiers, such as the MURS120, the circuit delivers 5V ±10% at 200 to 500 mA from a 5V ±5% input, with 77% efficiency. (DI #2502) Figure 1. A simple circuit produces a 5V, 1A isolated output from a 5V regulated input. Figure 2. The efficiency of the circuit in Figure 1 depends directly on the forward drops of the output rectifiers. Reprinted from EDN Magazine March 30, 2000 Copyright Cahners Business Information 2000 A Division of Reed Elsevier Inc. 自动更新 需要自动接收最新发布的应用笔记吗？请订阅EE-Mail™ (English only)。 我们期待您的反馈！ 喜欢？不喜欢？有待改善？或为我们提供建议？请与我们联系 — 我们将根据您的意见或建议改善我们的工作。 网页评价或提供建议   下载，PDF格式 (33kB)  AN674, AN 674, APP674, Appnote674, Appnote 674