随笔分类 - Circuit
摘要：This Design Idea stems from the limited availability of IC voltage regulators that can meet key USB-power specs, coupled with the need for turn-on seq...
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posted @ 2014-11-28 12:09
IAmAProgrammer
摘要：Voltage-regulator design for high output currents can be a critical and difficult task. Although voltage regulators with 1A maximum output current are...
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posted @ 2014-11-28 12:04
IAmAProgrammer
摘要：Adding a current-mirror circuit to a typical boost circuit allows you to select the amount of boost voltageand to ensure a constant difference between...
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posted @ 2014-11-28 12:01
IAmAProgrammer
摘要：The step-up switching-converter circuit inFigure 1presents a familiar problem: If you shut down boost converter IC1by pulling itsinput low, external i...
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posted @ 2014-11-28 11:37
IAmAProgrammer
摘要：In multiple-output power supplies in which a single supply powers circuitry of vastly different current draws, two perplexing steps are sensing the cu...
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posted @ 2014-11-28 11:06
IAmAProgrammer
摘要：Most isolated, offline SMPSs (switched-mode power supplies), including flyback, forward, and resonant, must operate at input voltages of 90 to 260V rm...
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posted @ 2014-11-28 10:59
IAmAProgrammer
摘要：Batteries are the typical power sources for portable-system applications, and it is not unusual these days to find microcontroller-based portable syst...
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posted @ 2014-11-28 10:53
IAmAProgrammer
摘要：An inexpensive way to implement high-resolution digital-to-analog conversion is to combine microcontroller-PWM (pulse-width-modulated) outputs with pr...
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posted @ 2014-11-28 10:50
IAmAProgrammer
摘要：Digital potentiometers, such asAnalog Devices’ AD5160, make excellent digitally controlled voltage dividers in applications in which 8-bit resolution ...
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posted @ 2014-11-28 10:48
IAmAProgrammer
摘要：Engineering labs are usually equipped with various power supplies, voltmeters, function generators, and oscilloscopes. One piece of equipment missing ...
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posted @ 2014-11-28 10:46
IAmAProgrammer
摘要：You can easily add margining capability—that is, the ability to digitally adjust the output voltage—to a dc/dc converter by making a single connection...
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posted @ 2014-11-28 10:42
IAmAProgrammer
摘要：Most engineers know that they can use an inexpensive, three-terminal adjustable regulator, such asFairchild Semiconductor’s LM317, as an adjustable re...
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posted @ 2014-11-28 10:35
IAmAProgrammer
摘要：Using a PN-junction diode for temperature measurement usually depends on its 2‑mV/K temperature coefficient. Conventionally, you must amplify and digi...
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posted @ 2014-11-28 10:30
IAmAProgrammer
摘要：Driving LEDs at a regulated current from low supply voltages can be difficult because minimal overhead voltage is available for control circuits. A cu...
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posted @ 2014-11-28 10:28
IAmAProgrammer
摘要：Sensors automate most of the processes in industry. Most of these sensors, such as those for ammonia gas, temperature, and the like, are resistive dev...
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posted @ 2014-11-28 10:26
IAmAProgrammer
摘要：Emerging digital ICs for power control lack basic features, such as the built-in gate drive and current limiting, that you would normally find in anal...
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posted @ 2014-11-28 10:24
IAmAProgrammer
摘要：The most common switching-power topology is a buck converter, which efficiently transforms high voltages to low voltages.Figure 1shows a typical buck ...
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posted @ 2014-11-28 10:19
IAmAProgrammer
摘要：A previous Design Idea describes a programmable current source that used a three-terminalNational SemiconductorLM317 adjustable regulator (Reference 1...
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posted @ 2014-11-28 10:17
IAmAProgrammer
摘要：Industrial controls make heavy use of 4- to 20-mA current loops to transmit process measurements because current loops retain information in the prese...
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posted @ 2014-11-28 10:13
IAmAProgrammer
摘要：A variable resistor that integrates a programmable, temperature-indexed look-up table can compensate for the temperature drift of a voltage regulator....
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posted @ 2014-11-28 10:07
IAmAProgrammer
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