Isolated supplies are required in most high-voltage systems that include low-voltage ICs. A simple approach is available for systems in which the potential difference is a fixed DC voltage, but in most cases the design and implementation of an isolated power supply is an involved endeavor. In Figure 1, the digital-oscillator circuit U1 contains a MOSFET driver whose complementary outputs drive a pair of capacitors (C1 and C2). The capacitors are connected to a full-wave rectifier formed by diodes D1-D4, and the rectifier outputs connect to a filter capacitor (C3). Additional diode-capacitor networks can be added as shown to create a multitude of isolated voltages, limited mainly by the maximum total load current of all outputs and the maximum drive available from U1 (over 1A for VCC = +18V). Figure 1. A MOSFET driver (U1) helps to generate multiple isolated voltages. The output voltages of this circuit are two diode drops below the input supply voltage. If the rectifiers are built with silicon small-signal diodes such as 1N914s, the circuit provides up to 4mA at 3.3V from a +5V input. Higher currents are available with larger diodes, and the substitution of Schottky for silicon diodes allows higher outputs by lowering the burden voltage. This circuit is suitable for systems with fixed DC potentials, but is less suitable for those in which the potential between low- and high-voltage sections is varying. A similar version of this article appeared in the December 23, 2002 issue of EDN magazine. 相关型号   APP 1932: Mar 14, 2003 MAX628 双路、功率MOSFET驱动器 完整的数据资料 (PDF, 184kB) 免费样品 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 (27kB)  AN1932, AN 1932, APP1932, Appnote1932, Appnote 1932