Most isolated, offline SMPSs (switched-mode power supplies), including flyback, forward, and resonant, must operate at input voltages of 90 to 260V rms. Some cases even use line-to-line voltages of 400V rms±10%, leading to increased component-voltage…

You would normally use a series linear regulator or a dc/dc converter to obtain 3V dc from a higher supply. However, when breadboarding a concept, you may be able to use a shunt regulator, especially if a series regulator of the correct voltage is un…

Figure 1 shows a simple, stand-alone overvoltage detector. The intent of the circuit is to monitor a voltage, VMONITOR, and set the output, VOUT, high when the monitored voltage exceeds a preset threshold. The minimum allowable threshold for this cir…

The circuit in Figure 1 is a good choice if you need a power supply with high efficiency and you don't want to use expensive dc/dc-converter ICs. The heart of the circuit is IC1, the common, inexpensive LM7805 linear regulator. The external switch is…

The schematic in Figure 1 shows a way to increase the power available from a current-limited 5V supply by adding power from a –5V supply. The dc/dc converter generates a single 12V, 150-mA (1.8W) output from two regulated and current-limited input so…

Batteries are the typical power sources for portable-system applications, and it is not unusual these days to find microcontroller-based portable systems. A variety of microcontrollers operates at low power-supply voltages, such as 1.8V. Thus you can…

BQ24296遇到的一点问题 概述:BQ24296是TI出品的具有窄范围VDC控制.基于I2C通讯的最大支持3A充电电流的开关式电源路径管理芯片.可以轻松实现2A以上的大电流充电,能量转换效率达到90%,同时支持OTG功能,可以把设备当成移动电源使用.缺点是充电的时候发热量比较大,目前还没有找到合理的解决办法.本文主要描述在项目应用过程中使用该芯片遇到的一点问题. 1.关机状态下接入USB(连接电脑),无法开机,屏幕没有显示. 接入UART输出LOG,发现接入USB后uboot能跑起来,而且在跑…

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…

http://www.powerguru.org/changing-the-output-voltage-of-a-switching-regulator-on-the-fly/ There are many different ways to change the output voltage Applications that require the output voltage of a power supply to change dynamically come from a wide…

转自蜗窝科技:http://www.wowotech.net/pm_subsystem/regulator_driver.html 说实话,这篇好难懂啊... 1. 前言 本文从regulator driver的角度,描述怎样基于regulator framework编写regulator驱动.同时,以此为契机,学习.理解regulator有关的物理特性,以便能够更好的使用它们. 2. regulator driver的实现步骤 2.1 确定系统中regulator有关的硬件组成  提起硬件,最…

转自蜗窝科技:http://www.wowotech.net/pm_subsystem/regulator_framework_overview.html 1. 前言 Regulator,中文名翻译为“稳定器”,在电子工程中,是voltage regulator(稳压器)或者current regulator(稳流器)的简称,指可以自动维持恒定电压(或电流)的装置. voltage regulator最早应用于功放电路中,主要用于滤除电源纹波(100或者120Hz)和噪声,以及避免“输出电压随负…

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…

前言 1.  什么是regulator?      regulator翻译为"调节器",分为voltage regulator(电压调节器)和current(电流调节器).一般电源管理芯片(Power Management IC)中会包含一个甚至多个regulator.   2.  regulator有什么作用?     通常的作用是给电子设备供电.大多数regulator可以启用(enable)和禁用(disable)其输出,同时也可以控制其输出电压(voltage)和电流(curr…

LDO Regulator High accuracy voltage regulator Vout = 2.5V * (1 + ( 5.6 / 6.8 ) ) = 4.55V Recently the author had to adapt  a standard circuit configuration  (which often uses an npn bipolar) so as to operate as a low-dropout (LDO) regulator. The circ…

The SEPIC (single-ended, primary-inductance-converter) topology is generally a good choice for voltage regulators that must produce an on output voltage that falls in the middle of the input-voltage range, such as a 5V output from a 2.7 to 6V input,…

Synchronous buck regulators offer high efficiency and are popular in applications in which available input voltages are 12V or less. However, as input voltage approaches 100V, wide-range-regulator design becomes more difficult, and the choice of suit…

Buck regulators find wide application as step-down regulators for converting large positive input voltages into a smaller positive output voltages. Figure 1 shows a simplified buck regulator that operates in continuous-conduction mode—that is, the in…

http://electronicdesign.com/print/passives/fixed-dc-dc-regulator-output-uses-digitally-controlled-potentiometer Electronic Design Tamara Schmitz Thu, 2009-10-01 (All day) Digitally controlled potentiometers (DCPs) have become very popular in a wide v…

A standard technique for generating analog voltages using µCs is to use a PWM output and filter the signal with a simple RC filter (Figure 1). The voltage of the PWM signal is directly proportional to the µC's supply voltage, so it is not necessarily…

Universally Compatible Wireless Power Using the Qi Protocol Wireless charging of portable electronic devices is here now. It will become ubiquitous when all such devices adhere to the same standard. By Upal Sengupta and Bill Johns, Texas Instruments…

RFID读写器的工作原理 RFID的数据采集以读写器为主导,RFID读写器是一种通过无线通信,实现对标签识别和内存数据的读出和写入操作的装置. 读写器又称为阅读器或读头(Reader).查询器(Interrogator).读出装置(Reading Device). 扫描器(Scanner).通信器(Communicator).编程/编码器(Programmer)等等. 读写器工作原理 RFID读写器的基本原理是利用射频信号与空间耦合传输特性,使电子标签与阅读器的耦合元件在射频耦合通道内进行能量传…

原文网址:http://blog.chinaunix.net/uid-28685940-id-3889878.html /*************************************************************************************************************************************//* bus.c */ /* *  linux/drivers/mmc/core/bus.c * *  Cop…

The TPS54331 is a 28-V, 3-A non-synchronous buck converter that integrates a low RDS(on) high side MOSFET. To increase efficiency at light loads, a pulse skipping Eco-mode™ feature is automatically activated. Furthermore, the 1 µA shutdown supply cur…

DC-DC Controllers Use Average-Current-Mode Control for Infotainment Applications Abstract: Auto infotainment products (multimedia and telematics) are demanding more power and challenging a vehicle's power-management systems. This application note exp…

---恢复内容开始--- OBDII Interface Project When I can ever find enough time away from schoolwork, I try to work on an OBDII compliant portable ScanTool. However, with my current course load and lab projects progress on this project has been very slow. I fi…

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en011794 In many applications, a DC/DC Converter is used to produce a regulated voltage or current, derived from an unregulated power supply, or from a battery. Ex…

http://learn.adafruit.com/ice-tube-clock-kit/design Tubes such as VFDs, Nixies, Decatrons, etc require high voltage to light the gas in the tube. For nixies, this iabout 170VDC. VFDs aren't as bad they only need about 30-50VDC. In order to reduce cos…

http://sourceforge.net/projects/openprogrammer/?source=navbar Open Programmer http://openprog.altervista.org/OP_eng.html#Quick Open Programmer v0.8.x Quick facts Completely free and Open Source (including firmware) Programs PIC10-12-16-18-24, dsPIC30…

It's a Buck; It's a Boost, No! It's a Switcher! Sanjaya Maniktala, National Semiconductor Corp., Santa Clara, CA We like to give everything a name or label very quickly. We probably feel we can then easily identify the object in the future, and also…

The USB (Universal Serial Bus) specification requires a connected USB device to present a load to the host or hub of no greater than 10 µF in parallel with 44Ω, including the effects of any bypass capacitance visible through the device’s voltage regu…