4.5 V To 55 V Input, 3 A, 5 A, 8 A, 12 A MicroBUCK DC/DC .

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SiC471, SiC472, SiC473, SiC474www.vishay.comVishay Siliconix4.5 V to 55 V Input, 3 A, 5 A, 8 A, 12 AmicroBUCK DC/DC ConverterFEATURESLINKS TO ADDITIONAL RESOURCESDesign ToolEvaluationBoardsDesign ToolsDESCRIPTIONThe SiC47x is a family of wide input voltage, high efficiencysynchronous buck regulators with integrated high sideand low side power MOSFETs. Its power stage is capableof supplying high continuous current at up to 2 MHzswitching frequency. This regulator produces an adjustableoutput voltage down to 0.8 V from 4.5 V to 55 V inputrail to accommodate a variety of applications, includingcomputing, consumer electronics, telecom, and industrial.SiC47x’s architecture allows for ultrafast transient responsewith minimum output capacitance and tight ripple regulationat very light load. The device enables loop stabilityregardless of the type of output capacitor used, includinglow ESR ceramic capacitors. The device also incorporates apower saving scheme that significantly increases light loadefficiency. The regulator integrates a full protection featureset, including over current protection (OCP), outputovervoltage protection (OVP), short circuit protection (SCP),output undervoltage protection (UVP) and over temperatureprotection (OTP). It also has UVLO for input rail and a userprogrammable soft start.The SiC47x family is available in 3 A, 5 A, 8 A, 12 A pincompatible 5 mm by 5 mm lead (Pb)-free power enhancedMLP55-27L package.TYPICAL APPLICATION CIRCUIT Versatile- Single supply operation from 4.5 V to 55 Vinput voltage- Adjustable output voltage down to 0.8 V- Scalable solution 3 A (SiC474), 5 A (SiC473),8 A (SiC472), 12 A (SiC471)- Output voltage tracking and sequencing with pre-biasstart up- 1 % output voltage accuracy at -40 C to 125 C Highly efficient- 98 % peak efficiency- 4 μA supply current at shutdown- 235 μA operating current, not switching Highly configurable- Adjustable switching frequency from 100 kHz to 2 MHz- Adjustable soft start and adjustable current limit- 3 modes of operation, forced continuous conduction,power save or ultrasonic Robust and reliable- Output over voltage protection- Output under voltage / short circuit protection with autoretry- Power good flag and over temperature protection- Supported by Vishay PowerCAD online designsimulation Material categorization: for definitions of complianceplease see www.vishay.com/doc?99912APPLICATIONS Industrial and automationHome automationIndustrial and server computingNetworking, telecom, and base station power suppliesUnregulated wall transformerRoboticsHigh end hobby electronics: remote control cars, planes,and drones Battery management systems Power tools Vending, ATM, and slot machinesAxis Title10010000VIN 24 V, VOUT 12 V98V DDCINSiC47xV DRVRxV SNSULTRASONICMODECyCxRupV FBSSILIMITCOMPPGNDfSWRlimitAGNDCss96V OUTSWCOUTRcompRdownCcompRfsw941000921st line2nd lineV INCBOOTPHASE2nd lineeff - Efficiency (%)BOOTENVCINPGOODINPUT4.5 VDC to 55 VDCVIN 48 V, VOUT 12 V90VIN 24 V, VOUT 5 V881008684VIN 48 V, VOUT 5 V8210800Fig. 1 - Typical Application Circuit for SiC47xS21-0217-Rev. F, 08-Mar-202112345678IOUT - Output Current (A)Fig. 2 - SiC472 Efficiency vs. Output CurrentDocument Number: 757861For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixBOOT 4PGND 1716 VDRVVDRV 1615 GL29 PGNDķ27 MODE26 VDD25 ILIM24 fSW23 AGND22 VFB21 COMP4 BOOTGL 1514 SWSW 1413 SWSW 1312 SWSW 1230 PGND29VINķPGND 10PGND 11PGND 9VIN 8VIN 7PHASE 63 EN5 PHASE6 PHASEPGND 1130VINPHASE 52 PGOODVIN 7EN 317 PGND28 AGNDVIN 828 AGNDPGOOD 2ULTRASONIC 18PGND 918 ULTRASONIC1 VCINSS 1919 SSPGND 10IJVCIN 120 VSNS20 VSNS21 COMP22 VFB23 AGND24 fSW25 ILIM26 VDD27 MODEPIN CONFIGURATIONFig. 3 - SiC47x Pin ConfigurationPIN DESCRIPTIONPIN NUMBERSYMBOLDESCRIPTION1VCINSupply voltage for internal regulators VDD and VDRV. This pin should be tied to VIN, but can also beconnected to a lower supply voltage ( 5 V) to reduce losses in the internal linear regulators2PGOOD3ENOpen-drain power good indicator - high impedance indicates power is good. An external pull-upresistor is requiredEnable pin. Tie high/low to enable/disable the IC accordingly. This is a high voltage compatible pin,can be tied to VIN4BOOTHigh side driver bootstrap voltage5, 6PHASEReturn path of high side gate driver7, 8, 29VIN9, 10, 11, 17, 30PGND12, 13, 14SWPower stage switch node15GLLow side MOSFET gate signal16VDRVSupply voltage for internal gate driver. When using the internal LDO as a bias power supply, VDRV isthe LDO output. Connect a 4.7 μF decoupling capacitor to PGND18ULTRASONICFloat to disable ultrasonic mode, connect to VDD to enable. Depending on the operation mode set bythe mode pin, power save mode or forced continuous mode will be enabled when the ultrasonicmode is disabled19SSSet the soft start ramp by connecting a capacitor to AGND. An internal current source will charge thecapacitor20VSNS21COMPOutput of the internal error amplifier. The feedback loop compensation network is connected fromthis pin to the AGND pin22VFBFeedback input for switching regulator used to program the output voltage - connect to an externalresistor divider from VOUT to AGND23, 28AGND24fSW25ILIMIT26VDD27MODES21-0217-Rev. F, 08-Mar-2021Power stage input voltage. Drain of high side MOSFETPower groundPower inductor signal feedback pin for system stability compensationAnalog groundSet the on-time by connecting a resistor to AGNDSet the current limit by connecting a resistor to AGNDBias supply for the IC. VDD is an LDO output, connect a 1 μF decoupling capacitor to AGNDSet various operation modes by connecting a resistor to AGND. See specification table for detailsDocument Number: 757862For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixORDERING INFORMATIONPART NUMBERPACKAGEMARKING CODEPowerPAK MLP55-27LSiC471ED-T1-GE3SiC471EVBSiC471Reference boardPowerPAK MLP55-27LSiC472ED-T1-GE3SiC472EVBSiC472Reference boardPowerPAK MLP55-27LSiC473ED-T1-GE3SiC473EVBSiC473Reference boardPowerPAK MLP55-27LSiC474ED-T1-GE3SiC474EVBSiC474Reference boardPART MARKING INFORMATION pin 1 indicatorP/NP/N Siliconix logoLL ESD symbolassembly factory codeFYWWpart number codeF Y year codeWW week codeLL lot codeABSOLUTE MAXIMUM RATINGS (TA 25 C, unless otherwise noted)ELECTRICAL PARAMETEREN, VCIN, VINCONDITIONSLIMITSReference to PGND-0.3 to 60SW / PHASEReference to PGND-0.3 to 60VDRVReference to PGND-0.3 to 6VDDReference to AGND-0.3 to 6Reference to PGND; 100 ns-10 to 66SW / PHASE (AC)BOOTV-0.3 to VPHASE VDRVAGND to PGNDAll other pinsUNIT-0.3 to 0.3Reference to AGND-0.3 to VDD 0.3Junction temperatureTJ-40 to 150Storage temperatureTSTG-65 to 150Temperature CPower DissipationThermal resistance from junction-to-ambient12Thermal resistance from junction-to-case2 C/WESD ProtectionElectrostatic discharge protectionHuman body model, JESD22-A1142000Charged device model, JESD22-A101500VStresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operationof the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximumrating/conditions for extended periods may affect device reliability.S21-0217-Rev. F, 08-Mar-2021Document Number: 757863For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixRECOMMENDED OPERATING CONDITIONS (all voltages referenced to GND 0 V)PARAMETERMIN.TYP.MAX.Input voltage (VIN)4.5-55Control input voltage (VCIN) (1)4.5-550-55Bias supply (VDD)4.7555.25Drive supply voltage (VDRV)4.755.35.55Output voltage (VOUT)0.8-0.92 x VINEnable (EN)UNITVTemperatureRecommended ambient temperature-40 to 105Operating junction temperature-40 to 125 CNote(1) For input voltages below 5 V, provide a separate supply to VCIN of at least 5 V to prevent the internal VDD rail UVLO from triggeringELECTRICAL SPECIFICATIONS (VIN VCIN 48 V, VEN 5 V, TJ -40 C to 125 C, unless otherwise stated)PARAMETERSYMBOLTEST CONDITIONSMIN.TYP.MAX.VIN VCIN 6 V to 55 VVIN VCIN 5 V4.7555.254.75-UNITPower SuppliesVDD supplyVDDVDD dropoutVDD DROPOUT-70-VDD UVLO44.254.5VVDD UVLO hysteresisVDD UVLO HYST-225-mVMaximum VDD currentIDD3--mAVIN VCIN 6 V to 55 V5.15.35.55VIN VCIN 5 V4.855.2VDD UVLO threshold, risingVIN VCIN 5 V, IVDD 1 mAVVIN VCIN 6 V to 55 VmVVDRV supplyVDRVVDRV dropoutVDRV DROPOUTVIN VCIN 5 V, IVDD 10 mA-160-mVVDRVVIN VCIN 6 V to 55 V50--mAVDRV UVLO44.254.5VVDRV UVLO HYST-295-mVMaximum VDRV currentVDRV UVLO threshold, risingVDRV UVLO hysteresisInput currentShutdown currentIVCINNon-switching, VFB 0.8 V-235325IVCIN SHDNVEN 0 V-48TJ 25 C796800804TJ -40 C to 125 C (1)792800808VμAController and TimingFeedback voltageVFBm/VVFB input bias currentIFB-2-nATransconductancegm-0.3-mSICOMP SOURCE1520-ICOMP SINK1520-tON MIN.-90110tON ACCURACY-10-10%tON RANGE110-8000nsUltrasonic mode enabled20-2000Ultrasonic mode disabled0-2000COMP source currentCOMP sink currentMinimum on-timetON accuracyOn-time rangeFrequency rangefswμAnskHzMinimum off-timetOFF MIN.190250310nsSoft start currentISS357μASoft start voltageVSS-1.5-VS21-0217-Rev. F, 08-Mar-2021When VOUT reaches regulationDocument Number: 757864For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixELECTRICAL SPECIFICATIONS (VIN VCIN 48 V, VEN 5 V, TJ -40 C to 125 C, unless otherwise stated)PARAMETERSYMBOLTEST CONDITIONSMIN.TYP.MAX.SiC471 (12 A),RILIM 60 kΩ, TJ -10 C to 125 C121518SiC472 (8 A),RILIM 60 kΩ, TJ -10 C to 125 C81012SiC473 (5 A),RILIM 43 kΩ, TJ -10 C to 125 C (2)5.678.4SiC474 (3 A),RILIM 60 kΩ, TJ -10 C to 125 C456-20---80-UNITFault ProtectionsValley current limitIOCPOutput OVP thresholdVOVPOutput UVP thresholdVUVPOver temperature protectionVFB with respect to 0.8 V referenceATOTP RISINGRising temperature-150-TOTP HYSTHysteresis-35-VFB RISING VTH OVVFB rising above 0.8 V reference-20-VFB FALLING VTH UVVFB falling below 0.8 V reference--10--50-% CPower GoodPower good output thresholdPower good hysteresisVFB HYST%mVPower good on resistanceRON PGOOD-7.515ΩPower good delay timetDLY PGOOD152535μsEN logic high levelVEN H-1.35-EN logic low levelVEN L-1.2-EN hysteresisVHYST-0.15-EN / MODE / Ultrasonic ThresholdREN-5-Ultrasonic mode high LevelEN pull down resistanceVULTRASONIC H2--Ultrasonic mode low levelVULTRASONIC L--0.8Mode pull up currentIMODE3.7556.25Mode 1Power save mode enabled, VDD, VDRVPre-reg on02100Mode 2Power save mode disabled, VDD, VDRVPre-reg on298301304Mode 3Power save mode disabled, VDRV Pre-regoff, VDD Pre-reg on, provide external VDRV494499504Mode 4Power save mode enabled, VDRV Pre-reg off,VDD Pre-reg on, provide external VDRV90010001100RMODEVMΩVμAkΩNotes(1) Guaranteed by design(2) Guaranteed by design for SiC473 OCP measurementsS21-0217-Rev. F, 08-Mar-2021Document Number: 757865For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixFUNCTIONAL BLOCK crectifierVDD UVLOHS UVLOEnableENfSWULTRASONICVINOn timegeneratorVDD5 μAtONMin. VPWMCOMPCOMPVDD0.8 V5 FBOver voltageunder er goodAGNDPGNDFig. 4 - SiC47x Functional Block DiagramOPERATIONAL DESCRIPTIONDevice OverviewPower StageSiC47x is a high efficiency synchronous buck regulatorfamily capable of delivering up to 12 A continuous current.The device has programmable switching frequency of100 kHz to 2 MHz. The voltage mode, constant on timecontrol scheme delivers fast transient response, minimizesthe number of external components and enables loopstability regardless of the type of output capacitor used,including low ESR ceramic capacitors. The device alsoincorporates a power saving feature that enables diodeemulation mode and frequency fold back as the loaddecreases.SiC47x integrates a high performance power stage with an-channel high side MOSFET and a n-channel low sideMOSFET optimized to achieve up to 98 % efficiency.SiC47x has a full set of protection and monitoring features: Over current protection in pulse-by-pulse mode Output overvoltage protection Output undervoltage protection with auto retry Over temperature protection with hysteresis Dedicated enable pin for easy power sequencing Power good open drain output This device is available in MLP55-27L package to deliverhigh power density and minimize PCB areaS21-0217-Rev. F, 08-Mar-2021The power input voltage (VIN) can go up to 55 V and downas low as 4.5 V for power conversion.Control SchemeSiC47x employs a voltage mode COT control mechanism inconjunction with adaptive zero current detection whichallows for power saving in discontinuous conduction mode(DCM). The switching frequency, fSW, is set by an externalresistor to AGND, Rfsw. The SiC47x operates between100 kHz to 2 MHz depending on VIN and VOUT conditions.V OUTR fsw --------------------------------------------12f sw 190 10Note, as long as VIN and VCIN are connected together, fSWhas no dependency on VIN as the on time is adjusted as VINvaries. During steady-state operation, feedback voltage(VFB) is compared with internal reference (0.8 V typ.) and theamplified error signal (VCOMP) is generated at the comp nodeby the external compensation components, RCOMP andCCOMP. An externally generated ramp signal and VCOMP feedinto a comparator. Once VRAMP crosses VCOMP, an on-timeDocument Number: 757866For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.compulse is generated for a fixed time. During the on-time pulse,the high side MOSFET will be turned on. Once the on-timepulse expires, the low side MOSFET will be turned on aftera dead time period. The low side MOSFET will stay on for aminimum duration equal to the minimum off-time (tOFF MIN.)and remains on until VRAMP crosses VCOMP. The cycle is thenrepeated.Fig. 6 illustrates the basic block diagram for voltage mode,constant on time architecture with external ripple injection,VRAMP, while Fig. 5 illustrates the basic operational principle.VRAMPVishay yR FB HEARCOMPCCOMPREFLoadR FB LFig. 6 - SiC47x Control Block DiagramBelow is the equation for calculating the VRAMP amplitude.VCOMP( V IN – V OUT ) V OUTV RAMP ---( V IN f sw C x R x )PWMFixed on-timeFig. 5 - SiC47x Operational PrincipleThe need for ripple injection in this architecture is explainedbelow. First, let us understand the basic principles of thiscontrol architecture: The reference of a basic voltage mode COT regulatoris replaced with a high gain error amplifier loop. The loopensures the DC component of the output voltage followsthe internal accurate reference voltage, providingexcellent regulation A second voltage feedback path via VSNS with a VRAMPscheme ensures rapid correction of the transientperturbation This establishes two voltage loops, one is the steady statevoltage feedback path (via the FB pin) and the other is thefeed forward path (via the VSNS pin). The scheme gives theuser the fast transient response of a COT regulator andthe stable, jitter free, line and load regulation performanceof a PWM controllerChoosing the Ripple Injection Component ValuesFor stability purposes the SiC47x requires adequate rippleinjection amplitude. Adequate ripple amplitude is requiredfor two main reasons:1. To reduce jitter due to noise coupled into the system2. To provide stable operation. Sub harmonic oscillationcan occur with constant on time ripple control if belowcondition is not mett ONESR C OUT --------2Therefore, when the converter design uses an all ceramicoutput capacitor or other low ESR output capacitors,instability can occur. In order to avoid this, a VRAMP networkis used to increase the equivalent RESR in order to satisfy theabove condition. The VRAMP amplitude must be largeenough to avoid instability or noise sensitivity but not toolarge that it degrades transient performance. To ensurestable operation under CCM, DCM and ultrasonic mode,minimum VRAMP amplitude of 100 mV is recommended forthe SiC47x family of regulators. A maximum VRAMP of900 mV is recommended so as not to degrade transientresponse.S21-0217-Rev. F, 08-Mar-2021VRAMP amplitude is a function of VIN, VOUT, and switchingfrequency and should be adjusted whenever VIN, VOUT, orswitching frequency is changed.For a given buck regulator design, VOUT and switchingfrequency is typically fixed, while the converter may beexpected to work for a wide VIN range. The VRAMP amplitudewill increase as VIN is increased and increase the powerdissipated by Rx. A proper selection of RX, package size andvalue, should take into account the maximum powerdissipation at the expected operating conditions.In order to optimize the VRAMP amplitude over a desired VINrange use the following procedure to calculate Rx, Cx, andCy.1. The equation below calculates RX as a function of VIN,VOUT, and maximum allowable power dissipated by RX.V IN MAX. V OUT ( 1 – D )R x -----------------P RX MAX.where PRX MAX. is the maximum allowed powerdissipation in Rx. Note, the maximum power dissipationof a 0603 sized resistor is typically 25 mW. Powerdissipation derating must be taken into account for highambient temperatures2. The equation below calculates CX MIN. as a function ofVIN and maximum allowed VRAMP amplitude.P RX MAX.C X MIN. ------------------------V IN MAX. f sw V RAMP MAX.where VRAMP MAX. 900 mV3. Using VRAMP equation, calculate VRAMP MIN. at minimumVIN based on the Rx and the minimum Cx valuecalculated above4. If VRAMP MIN. is 200 mV, set Cx to CX MIN., otherwise setCx to (Cx MIN. x VRAMP MIN./200 mV). If VRIPPLE MIN. is 100 mV, increase PRX MAX. and recalculate RX and CX5. Cy should be large enough not to distort the VRAMP andsmall enough not to load excessively the VRAMP network(Rx and Cx). Please use the follow formula:Cy 1/(820 x fsw)This procedure allows for a maximum range of operation.Document Number: 757867For technical questions, contact: powerictechsupport@vishay.comTHIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENTARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000

SiC471, SiC472, SiC473, SiC474www.vishay.comVishay SiliconixError Amplifier Compensation Value Selection (for reference only)RC

7, 8, 29 VIN Power stage input voltage. Drain of high side MOSFET 9, 10, 11, 17, 30 PGND Power ground 12, 13, 14 SW Power stage switch node 15 GL Low side MOSFET gate signal 16 VDRV Supply voltage for internal gate driver. When using the internal LDO as a bias power supply, V DRV is the LDO

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