SC441TETRT;中文规格书,Datasheet资料

来源：化拓教育网

NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441ASC441

POWER MANAGEMENTFeatures󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 󰂄 DESDNNEIGMSMEDO CEWRE N TRONFODescriptionWide input voltage range from 4.5V to 21V36V maximum output voltageDrives up to 40 WLEDs in 4 strings Programmable LED current for up to 150mA per string +/- 2% string-to-string current matchingUp to 90% efficiencyWide 0.2% to 100% PWM dimming rangePossible analog dimmingIntegrated 2.5A power switch800kHz switching frequency for small size Adjustable OVP for cost-effective output cap selectionOpen/short LED protectionThermal protection with auto-recoveryThermally enhanced TSSOP-20 EDP packageFully WEEE and RoHS compliantMedium-sized LCD panelNotebook Display

Automotive Car Navigation Display

Sub-Notebook and Tablet Computer DisplaysPortable Media Players

High Efficiency Integrated Driver for 4-Strings of 150mA LEDsThe SC441 is a high-efficiency multiple string WLED driver with an integrated boost converter. It operates over a wide input range from 4.5V to 21V with a maximum out-put voltage of 36V and a 2.5A internal power switch. It can drive up to forty WLEDs in 4 strings with current up to 150mA per string. The string-to-string current match-ing is 2% typical, 3% maximum. The overall efficiency is greater than 90% due to the low current sense voltage and a low-impedance internal power switch. The wide PWM dimming range boasts a ratio of 500: 1.The 800kHz switching frequency enables the user to op-timize the external component sizes for efficiency. When there are fewer than 10 LEDs in each string, users can ad-just the output voltage protection yielding an allowable reduction in associated costs, size and voltage ratings of the output capacitor.The SC441 also features comprehensive open and short-circuit LED protection functions. It disables the corre-sponding strings with LED open or LED short conditions while maintaining normal operation of other, unaffected LED strings. This feature allows LCD panels to remain view-able even under LED failure, wire disconnect, or short-cir-cuit conditions. The internal thermal shutdown protects the IC from overheating at abnormal conditions.The SC441 is available in a thermally-enhanced TSSOP-20 EDP package.

Applications󰂄 󰂄 󰂄 󰂄 󰂄

Typical Application Circuit

Vin (4.5V -21V)12VINENFFLAGPWMOVPRTNSWSWVOUTOVPINOVPIN4 StringsSC441IO1-4IO1-4IOSETIOSETAGNDAGND410COMPSSEDPPGNDPGNDIOGNDPGNDhttp://oneic.com/

September 28, 2010www.semtech.com1

NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441APin Configuration54SC441

DESDNNEIGMSMEDO CEWRE N TRONFO321Ordering InformationDevicePackageTSSOP-20 EDPEvaluation BoardSC441TETRT (1,2)DDIO2IO1120IO3IO4SC441EVBIOGNDAGNDSSPGNDSWSWCNotes:(1) Available in tape and reel only. A reel contains 2,500 devices.(2) Available in lead-free package only. Device is WEEE and RoHS Ccompliant.COMPPGNDENOVPINIOSETPWMOVPRTNVINBBVOUT1011FFLAGθJA = 39º C/WA (TSSOP-20 EDP)43A521Marking Information© 2010 Semtech Corporationhttp://oneic.com/

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441AAbsolute Maximum Ratings

SC441

VIN Pin: Supply Voltage …………………………… -0.3 to 25V

Maximum Output Power ……………………………… 22WIOSET Voltage ……………………………………… -0.3 to 2V

SW, OVPIN, OVPRTN, VOUT, IO1~IO4 Voltage …… -0.3 to 40V SS, COMP Voltage ………………………………… -0.3 to 4V EN, PWM, FFLAG Voltage …………………… -0.3 to VIN +0.3VPGND to AGND ……………………………………… ± 0.3VPeak IR Reflow Temperature …………………………… 260°CESD Protection Level(2) ……………………………… 2.5kVExceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not recommended.NOTES-(1) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.(2) Tested according to JEDEC standard JESD22-A114-B.Electrical CharacteristicsParameterInput Supply

Under-Voltage Lockout ThresholdUVLO Hysteresis

VIN Quiescent Supply CurrentVIN Supply Current in ShutdownOscillator

Switching FrequencyInternal Power SwitcherSwitch Current LimitSwitch Saturation VoltageSwitch Leakage CurrentMaximum Duty CycleMinimum Duty CycleMinimum On-Time(1)CompensationSourcing CurrentSinking Current

DESDNNEIGMSMEDO CEWRE N TRONFOSymbol

Conditions

UVLO-THUVLO-HIIN_QIIN_S FS

No switchingEN / PWM = low

VIN rising

Recommended Operating Conditions

Input Voltage Range ……………………………… 4.5V~21VMaximum Output Voltage ……………………………… 36VMaximum LED Current ……………………………… 150mA

Thermal Information

Junction to Ambient(1) ……………………………… 39°C/WMaximum Junction Temperature ……………………… 150°CStorage Temperature ………………………… -65 to +150°CLead Temperature (Soldering) 10 sec ………………… 260°C

Unless otherwise specified: VIN =12V, -40°C < TA = TJ < 105°C, RIOSET=1.74kW.

MinTypMaxUnits

4.32503

4.45VmVmA

1µA

0.0.80.96MHz

ISWVSATIS_LEAKDMAXDMINTON_MIN

ISW = 1A

2.53.322000.1

35010

100

AmVµA%%ns

88 93

IEA_SOURCEIEA_SINK

VCOMP = 0.5VVCOMP = 2V

µAµA

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441AElectrical Characteristics (continued)ParameterSymbolControl SignalsSC441

EN, PWM High VoltageEN, PWM Low VoltageEN, PWM Leakage CurrentPWM Dimming Frequency(1)PWM Dimming Minimum Pulse-WidthFFLAG VoltageSS Source CurrentSS Sink CurrentSS End ValuePWM Dimming Minimum Duty CycleSS Switching ThresholdOver-Voltage ProtectionOVPIN ThresholdOVPIN Leakage Current DESDNNEIGMSMEDO CEWRE N TRONFOConditionsVEN_H, VPWM_HVEN_L, VPWM_LIEN, IPWM FDimmingVEN, VPWM = 5VDMIN_DimmingTMIN_DimmingVFFLAGFDimming = 200HzFDimming = 200HzIFFLAG = 2 mAVSS = 0VISS_SOURCEISS_SINKVSS = 2V at OVP or OTPVIN = 12V, TJ = 25 °CVIN = 12VVSS_SwitchingVSS_ENDVOVPIN_THIOVPINVOVPRTNIOVPRTNIOVPIVOUT_LeakIO1~IO4IOMAXVIO_SCPIIO_LEAKTOTPTOTP_HTJ = 25 °C, VIO1 ~ VIO4EN = 0, VIO1 ~ VIO4 = VINOVPIN - AGNDVOVPIN = 20VIOVPRTN = 100 µAVOVPRTN = 20VVOUT = VIN + 3VVOUT = 40VTJ = 25 °CTJ = 25 °CMinTypMaxUnits20.40.1500.2100.253.510.70.92.61.491.550.1600.10.90.11402002.22.350.1150302.551150+/- 2160+/-31.05 1.611150kVVµAHz%µsVµAVVVµAmVµAmAµAmA%mAVµA°C°COVPRTN Saturation VoltageOVPRTN Leakage CurrentVOUT Internal Pull-down Current SourceVOUT Leakage CurrentCurrent Source (IO1 ~ IO4)Current AccuracyCurrent MatchingMaximum LED CurrentLED Short-Circuit ProtectionLeakage CurrentOver-Temperature ProtectionThermal Shutdown TemperatureThermal Shutdown HysteresisNotes:

(1) Guaranteed by design.

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441ATypical Characteristics SC441

DESDNNEIGMSMEDO CEWRE N TRONFOUVLO Threshold vs. TemperatureUVLO Hysteresis vs. Temperature4.3.354.344.334.324.314.304.29247246245244243242241240239238237UVLO Hysteresis (mV)VIN Quiescent Supply Current vs. Temperature3.203.103.002.902.802.702.602.50-4025105-4025105-4025105Temperature (oC)Temperature (oC)VIN Quiescent Supply Current (mA)VIN UVLO (V)Temperature (oC)COMP SINK / SOURCE Current vs. TemperatureVIN = 12VSS SINK / SOURCE Current vs. TemperatureSW Saturation Voltage at 1A vs. Temperature175170SW Saturation Voltage at 1A (mV)5.54.03.53.02.52.01.51.00.5VIN = 12VCOMP Sink / Source Current (uA)5.0SS Sink / Source Current (uA)SINKSOURCE165160155150145140135VIN = 4.5VVIN = 12VVIN = 21V4.54.0SINKSOURCE3.53.0-40251050.0-4025105-4025105Temperature (oC)Temperature (oC)Temperature (oC)

VOUT Pull Down Current Source

vs. Temperature0.930.91LED Current Source SCP Threshold

vs. Temperature2.4102.405Average LED Current Source Setting

vs. Temperature150.7150.6VIN = 12VLED Current Source Setting (mA)LED Current Source SCP Threshold (V)VOUT Pull down Current Source (mA)0.0.870.850.830.810.790.770.75-4025VIN = 4.5V2.4002.3952.3902.3852.3802.3752.3702.3652.360150.5150.4150.3150.2150.1150.0149.9149.8149.7VIN = 21VVOUT = VIN + 3V105VIN = 12VRIOSET = 1.78kW-4025105-4025105Temperature (oC)Temperature (oC)Temperature (oC)

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441ATypical Characteristics (continued)LED Current Source Saturation Voltage vs. LED CurrentTA = 25 oCSC441

240220200180160140120IFFLAG = 2mA92908886848280VIN = 21VPWM Dimming Minimum Pulse Width(uS)FFLAG Saturation Voltage (mV) DESDNNEIGMSMEDO CEWRE N TRONFOOVPRTN Saturation Voltage vs. Temperature9008007006005004003002001000OVPIN Threshold Voltage vs. Temperature1.5621.5601.5587570656055504540LED Current Source Saturation Voltage (mV)IOVPRTN = 100uAOVPRTN Saturation Voltage (V)OVPIN Threshold (V)1.5561.5541.5521.5501.5481.5461.544-4025105VIN = 12V1020406080100120140160-4025105LED Current (mA)Temperature (oC)Temperature (oC)FFLAG Saturation Voltage vs. TemperatureEfficiency ( PBOOST_OUTPUT / PINPUT)260948.58.07.57.06.56.05.55.04.54.03.50.2PWM Dimming Minimum Pulse Width vs. PWM Dimming FrequencyEfficiency (%)VIN = 12VVIN = 5V-4025105801602403204004805606000.51251020304050Temperature (oC)Boost Section Output Current (mA)

Condition: VOUT = 36V

PWM Dimming Frequency (kHz)

Condition: VIN = 12V, VOUT = 30V / 20mA x 4 strings

PWM Dimming Minimum Pulse Width

vs. PWM Dimming Frequency

PWM Dimming Minimum Pulse Width(uS)PWM Dimming Minimum Duty Cycle

vs. PWM Dimming Frequency

22PWM Dimming Minimum Duty Cycle(%)PWM Dimming Minimum Duty Cycle

vs. PWM Dimming Frequency

14PWM Dimming Minimum Duty Cycle(%)5.55.04.54.03.53.02.52.00.512510203040502018161412108200.20.5125102030405012108200.51251020304050PWM Dimming Frequency (kHz)

Condition: VIN = 12V, VOUT = 30V / 150mA x 4 strings

PWM Dimming Frequency (kHz)

Condition: VIN = 12V, VOUT = 30V / 20mA x 4 strings

PWM Dimming Frequency (kHz)

Condition: VIN = 12V, VOUT = 30V / 150mA x 4 strings

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441ATypical Characteristics (continued)

Start up

SC441

DESDNNEIGMSMEDO CEWRE N TRONFOVIN

(5V/DIV)

VIN

(10V/DIV)VSS(2V/DIV)

VSS(2V/DIV)

VSW

(20V/DIV)VOUT (20V/DIV)

VSW

(20V/DIV)VOUT (20V/DIV)

Shut Down

Time (20mS/DIV)Time (200mS/DIV)

Conditions: VIN = 12V,

Output = 27V / 20mA x 4 LED strings

Conditions: VIN = 19V, Output = 30V / 150mA x 4 LED strings

Main Power Switching Waveform

VSW

(20V/DIV)

VSW

(10V/DIV)

VOUT

Accoupling(200mV/DIV)

VOUT

Accoupling(100mV/DIV)

Time (1uS/DIV)

Conditions: VIN = 12V,

Output = 36V / 150mA x 4 LED strings

Time (400nS/DIV)

Conditions: VIN = 12V,

Output = 27V / 20mA x 4 LED strings

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441ATypical Characteristics (continued)

OTP and OTP Recovery

SC441

DESDNNEIGMSMEDO CEWRE N TRONFOVIN = 12VVSS

(2V/DIV)

VIN

(10V/DIV)

VSW

(20V/DIV)VOUT (20V/DIV)

VOUT(20V/DIV)IO1 (5V/DIV)IO2

(1V/DIV)

LED Short Circuit Protection

Time (40mS/DIV)Time (10mS/DIV)

Conditions: VIN = 12V, Output = 36V / 150mA x 4 LED strings Conditions: VIN = 12V, IO1 has one LED short circuit,

Output = 36V / 150mA x 4 LED strings

LED Open Circuit ProtectionPWM Dimming

VIN (5V/DIV)VOUT(20V/DIV)IO1

(10V/DIV)IO2

(1V/DIV)

VIN = 12V

PWM(2V/DIV)SW

(20V/DIV)IO1

(5V/DIV)

Time (10mS/DIV)

Conditions: VIN = 12V, IO2 LED String is open circuit,

Output = 36V / 150mA x 3 LED strings

Time (10mS/DIV)

Conditions: VIN = 12V,

Output = 36V / 50mA x 4 LED strings

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441APin DescriptionsPin #1234567Pin NameIO2IO1SC441

DESDNNEIGMSMEDO CEWRE N TRONFOPin FunctionProvides constant current source to LED string 2.Provides constant current source to LED string 1.Constant current source ground.Analog groundSoft-start pinIOGNDAGNDSSCOMPENEnable the device including regulator and LED drivers.IOSETPWMPWM dimming control pin for LED strings.101112131415,1816,171920EDPVOUTFFLAGVINOVPRTNOVPINPGNDSWIO4IO3Over-Voltage Protection sense signal return path pin.Over-Voltage Protection sense signal input.Power groundCollector of the internal power switch. The output of the internal trans-conductance error amplifier. Current source IO value set pin. By selecting the resistor connected from this pin to GND, the corresponding maximum current on all 4 strings are set.Internal pull down current source in over voltage fault. Connect this pin directly to Boost output.Power failure signal output with open collector. Held low under normal operation.Power input voltage pin. Bypassed with capacitors close to the pin.Provides constant current source to LED string 4. Connect to VIN for 3 strings operation.Provides constant current source to LED string 3.Solder to the ground plane of the PCB.Note: Any unused IO pin should be pulled up to VIN.EN

STATUS

backlight disablebacklight enable

Note: When EN = 0; the boost is turned OFF and disabled.

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NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441A5SC441

2Block DiagramFFLAGIO1IOSETIOGNDVOUTOVPOVPINOVPRTN0.9mAOVPDetectFaultHICCUP3V33.5uACONTROLLOGICHICCUPFaultVINUVLOUVLO & TSDBandgapENSSHICCUP1uAFigure 1. SC441 Block Diagram5432© 2010 Semtech Corporationhttp://oneic.com/

-LED CURRENTSETTINGCURRENTSOURCESSTSD-DISABLE1ISENSE- DESDNNEIGMSMEDO CEWRE N TRONFO43SWOSCSWSQHICCUPRONE IO CHANNEL SHOWNLED OPEN / SHORTCIRCUIT PROTECTIONFAULT-1+ILIMPGNDPGNDCOMP++PWMAGNDwww.semtech.com10

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SEMTECHSC441TETRT

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