External components provide true shutdown for boost converter

The step-up switching-converter circuit in Figure 1 presents a familiar problem: If you shut down boost converter IC1 by pulling its  input low, external inductor L1 and forward-biased Schottky diode D1 allow the load to continue drawing current. For battery-powered applications that present a heavy load—300 mA, for example—this unwanted dc-current path may quickly drain the battery. Adding an N-channel MOSFET, Q1, and a 100-kΩ resistor, R1, solves the problem by opening the unwanted current path during shutdown. The resulting circuit is suitable for battery-powered-system applications in which a microcontroller handles the power management.

Asserting a low logic level on the  input simultaneously shuts down the switching converter, a MAX756, and turns off the MOSFET, thereby blocking load current by removing the load‘s ground connection. When the  signal deasserts, the 100-kΩ pullup resistor turns on the MOSFET by pulling the MOSFET‘s gate high. With its ground reconnected, the load then draws current from the activated boost-converter circuit.

For optimum results at high load currents, select a logic-level MOSFET for Q1 that presents a reasonably low on-resistance. The MOSFET‘s drain-to-source breakdown voltage should also be able to withstand at least twice the maximum output voltage you expect from the boost converter. If necessary, you can reduce the MOSFET‘s effective on-resistance by connecting two or more MOSFETs in parallel.

时间： 2024-08-01 06:42:42

External components provide true shutdown for boost converter的相关文章

Use a microcontroller to design a boost converter

Boost converters, like other switchers, have traditionally received their control signals from a dedicated circuit. However, a recent trend is to integrate simple switching-power-supply building blocks into generic devices, such as microcontrollers.

Tracking Boost Regulator TYPICAL 5V REGULATION WITH BOOST CONVERTER AND LDO

Cs5171: Tracking Boost Regulator Adding a current mirror circuit to a typical boost circuit allows the user to select the amount of boost voltage and ensure a constant difference between input and output voltage. This is useful for high side drive ap

Digital Boost Converter Example for DSP

1 //########################################################################### 2 // 3 // Original Author: D.F. 4 // 5 // $TI Release: 2833x/2823x Header Files and Peripheral Examples V133 $ 6 // $Release Date: June 8, 2012 $ 7 //####################

Transformerless dc/dc converter produces bipolar outputs

The conventional way to produce dual (positive and negative) outputs from a single positive input is to use a transformer. Although such designs are relatively simple, the transformer inherently introduces the problem of size. It can be challenging t

Cascode MOSFET increases boost regulator's input- and output-voltage ranges

Targeting use in portable-system applications that require raising a battery's voltage to a higher level, IC boost regulators often include output transistors that can drive storage inductors. However, most boost regulators' absolute-maximum input-vo

Boost.Asio基本原理（CSDN也有Markdown了，好开森）

Boost.Asio基本原理 这一章涵盖了在使用Boost.Asio时必须知道的一些事情.我们也将深入研究比同步编程更复杂.更有乐趣的异步编程. 网络API 这一部分包含了当使用Boost.Asio编写网络应用程序时必须知道的事情. Boost.Asio命名空间 Boost.Asio的所有内容都包含在boost::asio命名空间或者其子命名空间内. * boost::asio:这是核心类和函数所在的地方.重要的类有io_service和streambuf.类似read, read_at, re

基于boost 的苹果apns消息推送实现(1)

1. 为了当时测试,做了2份C++代码实现,一份是基于boost的实现 较完整,一份是C++加Openssl实现(可以用,不少细节需要调整) 2. 本模块只涉及apns客户端部分 3. 涉及boost的主要模块有boost bind,boost asio,boost ssl,boost deadline_timer, boost 正则表达式 4. 有一点需要注意,最初使用的sslv23/sslv2/sslv3只能和apple 建立连接,但一直是handshake失败,郁闷了相当长一段时间 最后换

Boost.Asio基础（五） 异步编程初探

异步编程 本节深入讨论异步编程将遇到的若干问题.建议多次阅读,以便吃透这一节的内容,这一节是对整个boost.asio来说是非常重要的. 为什么需要异步 如前所述,通常同步编程要比异步编程更简单.同步编程下,我们很容易线性地对问题进行考量,函数A调用完,继续执行B,B执行完,继续执行C,以此类推,相对比较直观.而对于异步编程,假设有5个事件,我们很难知道它们具体的执行顺序,你甚至不知道,它到底会不会被执行. 虽然编写异步的程序,很难,但是依然需要使用这种方法.因为服务器程序需要同时并行的处理大量

Boost Asio 异步TCP服务器框架

Boost Asio 异步TCP服务器框架 flyfish 2015-5-30 session 类 头文件 #pragma once #include <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/shared_ptr.hpp> #include <boost/enable_shared_from_this.hpp> class session: public boost::enable