高的工作電壓高達100V N雙N溝道MOSFET同步驅動 The D810DCDC is a synchronous step-down switching regulator controlLER that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The D810DCDC uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit, without requiring a sense resistor. A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifi er provides very fast line and load transient response. Large 1Ω gate drivers allow the D810DCDC to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in VIN and can also be synchronized to an external clock for switching-noise sensitive applications. Integrated bias control generates gate drive power from the input supply during start-up and when an output shortcircuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher effi ciency.
Advancements in board assembly, PCB layout anddigital IC integration have produced a new generationof densely populated, high performance systems. Theboard-mounted point-of-load (POL) DC/DC power suppliesin these systems are subject to the same demandingsize, high power and performance requirements asother subsystems. The rigorous new POL demands aredifficult to meet with traditional controlLER or regulatorICs, or power modules.
Traditionally, an Electronic Circuit Breaker (ECB) comprisesa MOSFET, a MOSFET controlLER and a current senseresistor. The LTC®4213 does away with the sense resistorby using the RDS(ON) of the external MOSFET. The resultis a simple, small solution that offers a signifi cant lowinsertion loss advantage at low operating load voltage.The LTC4213 features two circuit breaking responses tovarying overload conditions with three selectable tripthresholds and a high side drive for an external N-channelMOSFET switch.
A number of conventional solutions have been available forthe design of a DC/DC converter where the output voltageis within the input voltage range—a common scenarioin Li-Ion battery-powered applications—but none werevery attractive until now. Conventional topologies, suchas SEPIC or boost followed by buck, have numerousdisadvantages, including low effi ciency, complex magnetics,polarity inversion and/or circuit complexity/cost. TheLTC®3785 buck-boost controlLER yields a simple, effi cient,low parts-count, single-converter solution that is easyto implement, thus avoiding the drawbacks associatedwith traditional solutions.
To this day, Power over Ethernet (PoE) continues to gainpopularity in today’s networking world. The 12.95Wdelivered to the Powered Device (PD) input supplied bythe Power Sourcing Equipment (PSE) is a universal supply.Each PD provides its own DC/DC conversion from anominal 48V supply, thus eliminating the need for a correctvoltage wall adapter. However, higher power devicescan not take advantage of standard PoE because of itspower limitations, and must rely on a large wall adapteras their primary supply. The new LTC4268-1 breaks thispower barrier by allowing for power of up to 35W for suchpower-hungry 2-pair PoE applications. The LTC4268-1provides a complete solution by integrating a high powerPD interface control with an isolated fl yback controlLER.
The LTC®4223 is a dual Hot Swap™ controlLER that meetsthe power requirements of the Micro TelecommunicationComputing Architecture (MicroTCA) specifi cation recentlyratifi ed by the PCI Industrial Computer ManufacturersGroup (PICMG).
Speed and accuracy don’t always go hand-in-handin DC/DC converter systems—that is, until now. TheLTC3811 is a dual output, fi xed frequency current modeDC/DC switching regulator controlLER designed for one oftoday’s most demanding power supply applications: highcurrent, low voltage processor core supplies.
Many telecommunications and computing applicationsneed high effi ciency step-down DC/DC converters thatcan operate from a very low input voltage. The highoutput power synchronous controlLER LT3740 is idealfor these applications, converting input supplies rangingfrom 2.2V to 22V to outputs as low as 0.8V with loadcurrents from 2A to 20A. Applications include distributedpower systems, point-of-load regulation and conversionof logic supplies.
Linear Technology’s DC/DC step-down μModule®regulators are complete switchmode power supplies in asurface-mount package. They include the DC/DC controlLER,inductor, power switches and supporting circuitry.These highly integrated regulators also provide an easysolution for applications that require negative outputvoltages. In other words, these products can operate asinverting buck-boost regulators. As a result, the lowestpotential in the circuit is not the standard 0V, but –VOUT,which must be tied to the μModule regulator’s GND. Allsignals are now referred to –VOUT.
