原标题：Linear LTC3216 42V 2.5A无损耗输入PowerPath电源解决方案

　　Linear公司的LTC3216是高效无损耗输入PowerPath降压电源稳压器,输入电压2.4V-42V,输出电压0.818V 到VIN输出电流2.5A,突发模式静态电流2uA,主要用在手持工业/通信测试设备,电池和超级电容备份电源,带电池备份的汽车电源以及不间断电源(UPS).本文介绍了LTC3216主要特性,框图,多种应用电路,以及演示板DC2215A测试图,电路图和材料清单.

　　The LTCR3126 is a high efficiency synchronous buckconverter with an internal no-loss PowerPath™ supportingseamless operation from two separate input power sources.

　　Pin-selectable ideal diode-OR and priority input modeswith user programmable undervoltage lockout thresholdsprovide full control over the transition between the inputpower sources. The fast, automatic switchover providedby the internal PowerPath eliminates the need for hold-upcapacitors and minimizes disturbances on the output rail.An active input channel indicator and independent inputand output power good signals provide complete feedbackof the power system status.

　　A wide 2.4V to 42V input voltage range, 2.5A output currentcapability and 2μA Burst Mode operation quiescentcurrent facilitate use of the LTC3126 with a wide varietyof power sources including supercapacitors, automotivebatteries, unregulated wall adapters and single tomulticell stacks of most battery chemistries. Additionalfeatures include 1μA current in shutdown, internal softstartand thermal protection. The LTC3126 is available in thermally enhanced 28-lead 4mm × 5mm QFN and28-lead TSSOP packages.

　　LTC3216主要特性:

　　Seamless, Automatic Transition Between Two InputPower Sources

　　Wide Input Voltage Range: 2.4V to 42V

　　Wide Output Voltage Range: 0.818V to VIN

　　Up to 2.5A Continuous Output Current

　　Pin-Selectable Priority and Ideal Diode-OR Modes

　　Burst ModeROperation, IQ = 2μA

　　95% Efficiency at 1A, VIN = 12V, VOUT = 5V

　　1μA Current in Shutdown

　　Programmable Input UVLO Thresholds

　　Input Valid, Priority Channel and PGOOD Indicators

　　200kHz to 2.2MHz Fixed frequency PWM

　　Synchronizable to an External Clock

　　Current Mode Control with 60ns Minimum On-Time

　　Minimal External Components

　　Thermally Enhanced 28-Lead 4mm × 5mm QFN and28-Lead TSSOP Packages

　　LTC3216应用:

　　Portable Industrial/Communications Test Equipment

　　Battery and Supercapacitor Backup Power

　　Automotive Power with Battery Backup

　　Uninterruptible Power Supplies

　　图1.LTC3216框图

　　图2.LTC3216应用电路图(1)

　　图3.LTC3216应用电路图(2)

　　图4.LTC3216应用电路图(3)

　　图5.LTC3216应用电路图(4)

　　图6.LTC3216应用电路图(5)

　　图7.LTC3216应用电路图(6)

　　图8.LTC3216应用电路图(7)

　　图9.LTC3216应用电路图(8)

　　图10.LTC3216应用电路图(9)

　　图11.LTC3216应用电路图(10)

　　图12.LTC3216应用电路图(11)

　　演示板DC2215A

　　Demonstration Circuit 2215A, features the LTC®3126, asynchronous buck converter with an integrated losslessinput PowerPath™. Pin selectable (JP2) ideal diode-ORand priority input modes, with programmable undervoltagelockout thresholds provide control over the transitionbetween input sources. The unique all N-channelarchitecture provides efficient operation from either oftwo input sources to a programmable output voltage.

　　In this application the valid input voltage range is setto be from 4.3V to 42V on VIN1 and from 6V to 8.4V onVIN2 providing flexibility and voltage margin for a varietyof applications and power sources. VIN2 can operate to42V. Other input voltage ranges are possible by adjustingVSET1/2 accordingly.

　　The LTC3126 uses a low noise, current mode architectureand a resistor programmable (R13) PWM oscillatorfrequency which is also synchronizable from 200kHz to2.2MHz. This minimizes the solution footprint while ensuringhigh efficiency. For higher efficiency at light loads, theuser can select Burst Mode® operation (JP1).

　　Burst Mode operation allows the automatictransition to PWM operation if the load current increases.More information on Burst Modeoperation and PWM mode can be found in the data sheet.

　　In some applications the efficiency can be improved bysetting the EXTVCC jumper (JP3) to VOUT. This allows theconverter to operate from the fixed VOUT voltage.

　　The system can be monitored through VALID1, VALID2,PRIORITY and PGOOD indicators. There are accurateVSET1 and VSET2 comparators to program independent UVLO thresholds. Consult the data sheet for informationon start-up and shutdown thresholds. Other featuresinclude a 1μA shut-down current (ENA pin JP4 = OFF),short-circuit protection, soft-start, inductor current limitand thermal overload protection.

　　The LTC3126 data sheet has detailed information aboutthe operation, specifications, and applications of the part.The data sheet should be read in conjunction with thisQuick Start Guide.

　　演示板DC2215A材料清单:

　　详情请见:

DC2215A-2-SCH.PDF.pdf

DC2215AF.PDF.pdf

3126f.pdf