LT3741/LT3741-1 High Power, Constant Current, …

1 LT3741/LT3741-1137411fgFor more information APPLICATIONDESCRIPTIONHigh Power, Constant current , Constant voltage , Step-Down ControllerThe LT 3741 and LT3741-1 are fixed frequency synchro-nous step-down DC/DC controllers designed to accurately regulate the output current at up to 20A. The average current -mode controller will maintain inductor current regulation over a wide output voltage range of 0V to (VIN 2V). The regulated current is set by an analog voltage on the CTRL pins and an external sense resistor. Due to its unique topology, the LT3741 is capable of sourcing and sinking current . If sinking current is not required, or for parallel applications, use the LT3741-1.

2 The regulated voltage and overvoltage protection are set with a voltage divider from the output to the FB pin. Soft-Start is provided to allow a gradual increase in the regulated current during startup. The switching frequency is programmable from 200kHz to 1 MHz through an external resistor on the RT pin or through the use of the SYNC pin and an external clock Features include an accurate external reference voltage for use with the CTRL pins, an accurate UVLO/EN pin that allows for programmable UVLO hysteresis, and thermal Constant current , Constant voltage Step-Down ConverterFEATURESAPPLICATIONS nControl Pin Provides Accurate Control of Regulated Output current n voltage Regulation Accuracy n 6% current Regulation Accuracy n6V to 36V Input voltage Range nWide Output voltage Range Up to (VIN 2V)

3 NAverage current Mode Control n<1 A Shutdown current nUp to 94% Efficiency nAdditional Pin for Thermal Control of Load current nThermally Enhanced 4mm 4mm QFN and 20-Pin FE Package nGeneral Purpose Industrial nSuper-Cap Charging nApplications Needing Extreme Short-Circuit Protec-tion and/or Accurate Output current Limit nConstant current or Constant voltage SourceEN/UVLOEN/UVLOHGVINCBOOTVREFVCCTRL 1 CTRL2LT3741 RTSYNCSWLGGNDSENSE+SENSE H22 F 210nFRNTC100 FVIN14V TO 36 VVOUT10V20A1 (A)02468 10 12 14 16 18 VOUT (V)6812103741 TA01b4202220 VIN = 18 VVOUT = 10 VILIMIT = 20 AVOUT vs IOUTAll registered trademarks and trademarks are the property of their respective owners.

4 Protected by Patents including 7199560, 7321203 and others more information voltage ..40 VEN/UVLO voltage ..6 VVREF voltage ..3 VCTRL1 and CTRL2 voltage ..3 VSENSE+ voltage ..40 VSENSE voltage ..40 VVC voltage ..3 VSW voltage ..40 VCBOOT ..46V(Note 1)ORDER INFORMATIONLEAD FREE FINISHTAPE AND REELPART MARKING*PACKAGE DESCRIPTIONTEMPERATURE RANGELT3741 EUF#PBFLT3741 EUF#TRPBF374120-Lead (4mm 4mm) Plastic QFN 40 C to 125 CLT3741 IUF#PBFLT3741 IUF#TRPBF374120-Lead (4mm 4mm) Plastic QFN 40 C to 125 CLT3741 EFE#PBFLT3741 EFE#TRPBFLT3741FE20-Lead Plastic TSSOP 40 C to 125 CLT3741 IFE#PBFLT3741 IFE#TRPBFLT3741FE20-Lead Plastic TSSOP 40 C to 125 CLT3741 EUF-1#PBFLT3741 EUF-1#TRPBF3741120-Lead (4mm 4mm) Plastic QFN 40 C to 125 CLT3741 IUF-1#PBFLT3741 IUF-1#TRPBF3741120-Lead (4mm 4mm)

5 Plastic QFN 40 C to 125 CLT3741 EFE-1#PBFLT3741 EFE-1#TRPBFLT3741FE-120-Lead Plastic TSSOP 40 C to 125 CLT3741 IFE-1#PBFLT3741 IFE-1#TRPBFLT3741FE-120-Lead Plastic TSSOP 40 C to 125 CConsult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: For more information on tape and reel specifications, go to: Some packages are available in 500 unit reels through designated sales channels with #TRMPBF MAXIMUM RATINGS2019181716678 TOP VIEW21 GNDUF PACKAGE20-LEAD (4mm 4mm) PLASTIC QFN910543211112131415EN/UVLOVREFCTRL2 GNDCTRL1 HGGNDSYNCRTGNDVINVCC_INTLGCBOOTSWSSFBSEN SE+SENSE VC TJMAX = 125 C, JA = 37 C/W EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCBFE PACKAGE20-LEAD PLASTIC TSSOP12345678910 TOP VIEW20191817161514131211 VCC_INTGNDVINEN/UVLOVREFCTRL2 GNDCTRL1 SSFBLGCBOOTSWHGGNDSYNCRTVCSENSE SENSE+21 GND TJMAX = 125 C, JA = 38 C/W EXPOSED PAD (PIN 21)

6 IS GND, MUST BE SOLDERED TO PCBPIN CONFIGURATIONRT voltage ..3 VFB voltage ..3 VSS voltage ..6 VVCC_INT voltage ..6 VSYNC voltage ..6 VStorage Temper atur e Range .. 65 C to 150 CLead Temper atur e (Soldering, 10 sec) TSSOP ..300 #orderinfoLT3741/LT3741-1337411fgFor more information CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25 C. VIN = 12V, VEN/UVLO = 5V, VSYNC = 0V unless otherwise voltage Rangel636 VVIN Pin Quiescent current (Note 2) Non-Switching Operation Shutdown Mode Not Switching VEN/UVLO = 0V, RT = 40k l 1 mA AEN/UVLO Pin Falling Hysteresis130mVEN/UVLO Pin CurrentVIN = 6V, EN/UVLO = ASYNC Pin Threshold1 VCTRL1 Pin Control Pin CurrentCTRL1 = 100nAReferenceReference voltage (VREF Pin) current SensingFull Range SENSE+ to SENSE VCTRL1 = + Pin CurrentVSENSE+ = 6V50nASENSE Pin CurrentWith VOUT ~ 4V, VCTRL1 = 0V, VSENSE = 6V10 AInternal VCC Regulator (VCC_INT Pin)

7 Regulation FET DriverNon-Overlap time HG to LG(Note 3)100nsNon-Overlap time LG to HG(Note 3)60nsMinimum On-Time LG(Note 3)50nsMinimum On-Time HG(Note 3)80nsMinimum Off-Time LG(Note 3)65nsHigh Side Driver Switch On-Resistance Gate Pull Up Gate Pull DownVCBOOT VSW = 5V Low Side Driver Switch On-Resistance Gate Pull Up Gate Pull DownVCC_INT = 5V 1 Switching FrequencyfSWRT = 40k RT = 200k l900 1851000 2001070 233kHz kHzSoft-StartCharging Current11 AVoltage Regulation AmplifierInput Bias CurrentFB = 800 A/VFeedback Regulation VoltageCTRL1 = , ISENSE = 23 A, VSENSE+ = more information PERFORMANCE CHARACTERISTICSEN/UVLO Threshold (Falling)

8 EN/UVLO Pin CurrentIQ in ShutdownELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25 C. VIN = 12V, VEN/UVLO = 5V, VSYNC = 0V unless otherwise Control Loop gm AmpOffset VoltageVCM =4Vl 303mVInput Common Mode Range VCM(LOW) VCM(HIGH) VCM(HIGH) Measured from VIN to VCM 0 2 V VOutput gm375475625 A/VDifferential 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and 2: The LT3741E is guaranteed to meet performance specifications from 0 C to 125 C junction temperature.

9 Specifications over the 40 C to 125 C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LT3741I is guaranteed to meet performance specifications over the 40 C to 125 C operating junction temperature 3: The minimum on, off, and nonoverlap times are guaranteed by design and are not (V)6EN/UVLO THRESHOLD (V) 50 C130 C3741 (V)6EN/UVLO PIN current ( A)6810303741 G024201218243625 C130 C 50 CVIN (V)0IQ ( A) C25 CQuiescent current (Non-Switching)VIN (V)6 QUIESCENT current (mA) = 25 CTA = 130 CTA = 50 CLT3741/LT3741-1537411fgFor more information PERFORMANCE CHARACTERISTICSVREF Pin VoltageVREF current LimitTEMPERATURE ( C) 50 VREF voltage (V) 152055125 VIN = 36 VVIN = 6 VVIN (V)6 ILIMIT (mA) = 25 CTA = 130 CTA = 50 CRT Pin current LimitSoft-Start Pin CurrentTEMPERATURE ( C) 50 ILIMIT ( A)

10 708090903741 G08605040 152055125 TEMPERATURE ( C) 50 ISS ( A)891413121110903741 G0976 152055125 VIN = 36 VVIN = 6 VVCC_INT current LimitILOAD (mA)0 VCC_INT (V)456503741 G0731201020403060 VIN = 12 VTA = 25 CVCC_INT Load Reg at 12 VCBOOT-SW UVLO VoltageVCC_INT UVLOTEMPERATURE ( C) (V) 152055903741 G11125 TEMPERATURE ( C) (V) 152055903741 G12125 ILOAD (mA)0 VCC_INT (V) CInternal UVLOTEMPERATURE ( C) 50 VIN (V) 152055125LT3741/LT3741-1637411fgFor more information PERFORMANCE CHARACTERISTICSR egulated current vs VFBO vervoltage ThresholdOvervoltage TimeoutRegulated Sense VoltageCommon Mode LockoutNon-Overlap TimeMinimum Off-TimeHG Driver RDS(ON)LG Driver RDS(ON)VFB (V) 150 CONTROL current (%) 100 ( C) 50 OVERVOLTAGE THRESHOLD (V) 250255075125 TEMPERATURE ( C) 50 OVERVOLTAGE TIMEOUT ( s)151719903741 G1613119 152055125 VCTRL (V)00 VSENSE+ VSENSE (mV) ( C) 50CM LOCKOUT (V) 152055125 VIN = 6 VVIN = 36 VMEASURED VIN VOUTTEMPERATURE ( C) 50 RDS(ON) ( )