Abstract: The DS1875 features a pulse-width modulation (PWM) controller that can be used to control aDC-DC converter. The DC-DC converter can then be used to generate the high bias voltages necessaryfor avalanche photodiodes (APDs). This apPLication note describes the operation of a boost converterthat uses the DS1875. Discussion covers the selection of the inductor and switching frequency, and theselection of components that improve the efficiency of the converter. Test data are presented.
上传时间: 2013-10-26
上传用户:lyson
Abstract: There are many things to consider when designing a power supply for a field-programmablegate array (FPGA). These include (but are not limited to) the high number of voltage rails, and thediffering requirements for both sequencing/tracking and the voltage ripple limits. This apPLication noteexplains these and other power-supply considerations that an engineer must think through whendesigning a power supply for an FPGA.
上传时间: 2013-11-12
上传用户:金苑科技
Abstract: A resistive feedback network is often used to set the output voltage of a power supply. A mechanical potentiometer (pot)conveniently solves the problem of adjusting a power supply. For easier automatic calibration, a mechanical pot can be replaced witha digital pot. This apPLication note presents a calibration solution that uses a digital pot, because digipots are smaller, do not movewith age or vibration, and can be recalibrated remotely. This proposed solution reduces the susceptibility of the system to thetolerance of the digital pot's end-to-end resistance, making the solution optimal fordesigners. This apPLication note also explainssome of the equations required to calculate the resistor chain values and to use a digital pot in this way. A spreadsheet withstandard reisistor values is available for easy calculations.
上传时间: 2013-10-31
上传用户:caiguoqing
Abstract: Field-programmable gate arrays (FPGAs) are used in a wide variety of apPLications and end markets, including digital signalprocessing, medical imaging, and high-performance computing. This apPLication note outlines the issues related to powering FPGAs.It also discusses Maxim's solutions for powering Altera® FPGAs.
上传时间: 2013-11-02
上传用户:zhaoman32
Abstract: With its small size and large load (10W) capability, the MAX13256 H-bridge transformer driver is an attractive solution forcharging supercapacitors (supercaps). However, a large capacitance on the output of the circuit can force the driver into fault modeat startup, due to the high initial charge current. This apPLication note presents a solution that allows users to charge a largecapacitance without going into fault.
上传时间: 2013-10-20
上传用户:2728460838
Abstract: Some types of loads require more current during startup than when running. Other loads can be limited to a lower-powercurrent during startup but require a higher operating current. This article describes an apPLication circuit that automatically adjusts apower circuit’s overcurrent protection level up or down after startup is complete.
上传时间: 2013-10-23
上传用户:swaylong
The MAX14885E, a 2:2 VGA switch, connects a VGA source to a VGA monitor. To ease direct connection to graphics controllers orthe ASIC, the MAX14885E has two supplies: VCC, a 5V ±5% supply, drives the VGA side interface; and the VL supply sets the logicswitching thresholds on the digital input pins (EN, S00, S01, S10, S11, SHA, SHB, SVA, and SVB). This apPLication note documentsthe proper sequencing of the VCC and VL power supplies on power-up.
上传时间: 2013-10-23
上传用户:wuchunzhong
DC/DC 升压IC:The FP6291 is a current mode boost DC-DC converter. Its PWM circuitry with built-in 0.25 Ω power MOSFET make this regulator highly power efficient. The internal compensation network also minimizes as much as 6 external component counts. The non-inverting input of error amplifier connects to a 0.6V precision reference voltage and internal soft-start function can reduce the inrush current. The FP6291 is available in the SOT23-6L package and provides space-saving PCB for the apPLication fields.
上传时间: 2013-11-07
上传用户:3294322651
The LTC3546 is a dual output current mode buck regulatorwith fl exible output current partitioning. Beyondthe advantages normally associated with dual outputregulators (reduced size, cost, EMI and part count, withimproved effi ciency), the LTC3546’s outputs can bepartitioned for either 3A and 1A outputs, or two 2A outputs.This increases its apPLication range and simplifi esmultiple supply rail designs. A confi gurable Burst Mode®clamp for each output sets the current transition levelbetween Burst Mode operation and forced continuousconduction mode to optimize effi ciency over the entireoutput range. An adjustable switching frequency up to4MHz and internal power MOSFET switches allow forsmall and compact footprints.
上传时间: 2013-11-04
上传用户:yxgi5
Specifying the right reference and applying it correctly isa more difficult task than one might first surmise, consideringthat references are only 2- or 3-terminal devices.Although the word “accuracy” is most often spoken inreference to references, it is dangerous to use this wordtoo freely because it can mean different things to differentpeople. Even more perplexing is the fact that a referenceclassified as a dog in one apPLication is a panacea inanother. This apPLication note will familiarize the readerwith the various aspects of reference “accuracy” andpresent some tips on extracting maximum performancefrom any reference.
标签: 电压基准
上传时间: 2013-10-15
上传用户:liuwei6419