Abstract: A delay line with some external logic can be combined to implement a one-shot function. This article outlines how to perform this configuration and make the required calculations to develop the pulse width needed for a certain application. The article gives an example of a one-shot developed using a fixed delay line for a fixed one-shot output. Programmable delay lines such as the DS1020, DS1021 and DS1023 are available, which could be configured in the same manner to provide a programmable one-shot circuit which could be used as the duty cycle modulator in a pulse-width modulator (PWM) circuit. Some external logic can be combined with a delay line to implement a one-shot function. This approach has the advantage that it eliminates the need for RC timing components and can offer improved accuracy. If a tapped delay line is used, it can be combined with a multiplexer, DIP switches, or jumpers to offer several different output pulse widths, under system control or hard-wired. The realizable accuracy will be determined by how the logic is implemented and the associated propagation delays through it compared to the chosen delay time. Ideally, the external propagation delays should be small compared to the delay time, in which case the output pulse width will be close to the delay time used. The various propagation delays have the following effects on overall system performance: the inverter propagation delay (tPD1) directly affects the output pulse width; the NOR gate propagation delay (tPD2), in conjunction with the inverter propagation delay, will affect the skew between input and output. TTL logic, although easy to implement, suffers from relatively large propagation delays depending on family, (e.g., LS, FAST) and from wide tolerances at room temperature and over the operating range. For shorter pulse widths and tighter tolerance, it may be preferable to implement the function using discrete transistors (RTL). One member of the Silicon Timed Circuit family, the DS1040 preconfigured as a one-shot, and offers similar functionality without requiring external components. 相关型号   APP 977: Feb 22, 2002 DS1020 可编程、8位、硅延迟线 完整的数据资料 (PDF, 200kB) DS1021 可编程、8位、硅延迟线 完整的数据资料 (PDF, 208kB) 免费样品 DS1023 8位、可编程定时单元 完整的数据资料 (PDF, 256kB) 免费样品 DS1040 可编程、单稳态脉冲发生器 完整的数据资料 (PDF, 160kB) DS1100 5抽头、经济型定时单元(延迟线) 完整的数据资料 (PDF, 168kB) 免费样品 DS1135 3合1、高速硅延迟线 完整的数据资料 (PDF, 136kB) 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 (33kB)  AN977, AN 977, APP977, Appnote977, Appnote 977