Sensing and/or controlling current flow is a fundamental requirement in many electronics systems, and the tech-niques to do so are as diverse as the applications them-selves.
标签: 电流采样
上传时间: 2013-10-15
上传用户:daoyue
Smart Batteries are an increasingly popular choice formore than just traditional compact consumer electronicdevices. For example, Smart Batteries are being used asbattery backup for products such as blade servers, whereknowing battery status is very important
上传时间: 2013-11-02
上传用户:wangzhen1990
Linear Technology offers a variety of devices that simplifyconverting power from a USB cable, but the LTC®3455represents the highest level of functional integration yet. The LTC3455 seamlessly manages power flowbetween an AC adapter, USB cable and Li-ion battery,while complying with USB power standards, all from a4mm × 4mm QFN package. In addtion, two high efficiencysynchronous buck converters generate low voltage railswhich most USB-powered peripherals require. TheLTC3455 also provides power-on reset signals for themicroprocessor, a Hot SwapTM output for poweringmemory cards as well as an uncommitted gain blocksuitable for use as a low-battery comparator or an LDOcontroller. The PCB real estate required for the entire USBpower control circuit and two DC/DC converters is only225mm2.
上传时间: 2013-11-02
上传用户:名爵少年
The core voltages for FPGAs are moving lower as a resultof advances in the fabrication process. The newest FPGAfamily from Altera, the Stratix® II, now requires a corevoltage of 1.2V and the Stratix, Stratix GX, HardCopy®Stratix and CycloneTM families require a core voltage of1.5V. This article discusses how to power the core and I/Oof low voltage FPGAs using the latest step-down switchmode controllers from Linear Technology Corporation.
上传时间: 2013-10-08
上传用户:wangfei22
The LTC®3414 offers a compact and efficient voltage regulatorsolution for point of load conversion in electronicsystems that require low output voltages (down to 0.8V)from a 2.5V to 5V power bus. Internal power MOSFETswitches, with only 67mW on-resistance, allow theLTC3414 to deliver up to 4A of output current with efficiencyas high as 94%. The LTC3414 saves space by operatingwith switching frequencies as high as 4MHz, enabling theuse of tiny inductors and capacitors.
上传时间: 2014-01-03
上传用户:dongbaobao
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
Although recent popular attention is focused on LithiumIon batteries, one must not forget that other batterychemistries, such as Nickel Cadmium (NiCd) and NickelMetal Hydride (NiMH) have advantages in rechargeablepower systems. Nickel-based batteries are robust, capableof high discharge rates, have good cycle life, do notrequire special protection circuitry and are less expensivethan Li-Ion. Among the two, NiMH batteries are rapidlyreplacing NiCd because of their higher capacity (40% to50% more) and the environmental concerns of the toxiccadmium contained in NiCd batteries.
上传时间: 2013-11-04
上传用户:qq10538412
Low power standby requirements are typically associatedwith battery-powered systems. Automotive systems,for example, commonly require power supplies tomaintain output voltage regulation even under no-loadconditions—while drawing minimal quiescent current topreserve battery life. Rising energy costs, however, haveextended the need for low current standby operation toline-powered systems, such as small plugged-in appliancesfor home and business.
上传时间: 2013-11-20
上传用户:xinyuzhiqiwuwu
Many complex systems—such as telecom equipment,memory modules, optical systems, networking equipment,servers and base stations—use FPGAs and otherdigital ICs that require multiple voltage rails that muststart up and shut down in a specific order, otherwise theICs can be damaged. The LTC®2924 is a simple andcompact solution to power supply sequencing in a 16-pinSSOP package (see Figures 1 and 2).
上传时间: 2013-10-29
上传用户:tonyshao
As the performance of many handheld devices approachesthat of laptop computers, design complexity also increases.Chief among them is thermal management—how doyou meet increasing performance demands while keepinga compact and small product cool in the user’s hand?For instance, as battery capacities inevitably increase,charge currents will also increase to maintain or improvetheir charge times. Traditional linear regulator-based batterychargers will not be able to meet the charge currentand effi ciency demands necessary to allow a product torun cool. What is needed is a switching-based chargerthat takes just about the same amount of space as a linearsolution—but without the heat.
上传时间: 2013-11-23
上传用户:lu2767