LT3120 (Rev. 0) - Analog Devices

1 LT31201 Rev. 0 For more information FeedbackTYPICAL APPLICATION FEATURESDESCRIPTION26V, 9A Low-IQ CC/CV Monolithic buck -Boost ConverterThe LT 3120 is a high efficiency 26V monolithic buck -boost converter. Extensive feature integration and very low resistance internal power switches minimize the total solution footprint for even the most demanding applica-tions. A proprietary 4- switch PWM architecture provides seamless low noise operation from input voltages above, equal to, or below the output frequency programming as well as synchroniza-tion using an internal PLL enable operation over a wide switching frequency range of 400kHz to 2 MHz. The wide to 26V input range is well suited for operation from unregulated power sources including battery stacks and backup capacitors.

2 After start-up, operation is possible with input voltages as low as features include, output short-circuit protection, thermal overload protection, less than 3 A shutdown cur-rent, power good indicator, Burst Mode operation, and maximum power point LT3120 is offered in thermally enhanced 28-lead 4mm 5mm LQFN Input Range 750kHz 5V RegulatorAPPLICATIONS nInput Voltage Range: to 26V to 24V Output Voltage Range nHigh Output Current with VOUT = 5V, VIN > 6V n3A with VOUT = 5V, VIN = 3V with VOUT = 12V, VIN > 14V n4 A with VOUT = 12V, VIN = 9V nUltralow Noise buck -Boost Architecture nProgrammable Output Current Limit nProgrammable Frequency Range: 400kHz to 2 MHz nAccurate Enable Comparator Threshold nBurst Mode Operation, No-Load IQ = 35 A nCurrent Mode Control nExternal Clock Synchronization nMaximum power Point Control n28-Lead 4mm 5mm LQFN Package nRF power Supply nUSB power Delivery nSystem Backup power Supply n1-Cell to 5-Cell Lithium Battery Powered Products nWide Input Range power Supply nLead Acid to 12V RegulatorAll registered trademarks and trademarks are the property of their respective owners.

3 Efficiency, VOUT = 5V, fSW = 750kHzPWMB urst Mode OPERATIONVIN = 3 VVIN = 12 VVIN = 20 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 F105k10 to 26V5 VVIN = ; IOUT = ; EFFICIENCY = 85%VIN = ; IOUT = ; EFFICIENCY = 86%3120 TA01aLT31202 Rev. 0 For more information CONFIGURATIONABSOLUTE MAXIMUM RATINGSVIN, PVIN, PVOUT, EN/UVLO, PGOOD .. to 27 VFB, VC, RT, SYNC/MODE, MPPC, VCC .. to 6 VBST1 ..(SW1 ) to (SW1 + 6V)BST2 ..(SW2 ) to (SW2 + 6V)BST3 ..(PVOUT ) to (PVOUT + 6V)Operating Junction Temperature (Note 2) LT3120J .. 40 C to 150 CStorage Temperature Range .. 65 C to 150 CMaximum Reflow (Package Body) Temperature .. 260 C(Note 1)910 TOP VIEWLQFN PACKAGE28-LEAD (4mm 5mm) LGATJMAX = 150 C, JA = 20 C/WEXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB11121328 27 26 25 241423654321 BST3 PVOUTGNDPVOUTISPISNPGOODPROGGNDPVINPVINP VINGNDVINEN/UVLOSYNC/MODE29 PGNDBST2SW2SW2SW1SW1 BST1 FBVCGNDMPPCVCCRT717181920212216815 ORDER INFORMATIONPART NUMBERPAD OR BALL FINISHPART MARKINGPACKAGE TYPEMSL RATINGTEMPERATURE RANGE (SEE NOTE 2)DEVICE FINISH CODELT3120JV#PBFAu (RoHS)3120e4 LQFN (Laminate Package with QFN Footprint)3 40 C to 150 C Contact the factory for parts specified with wider operating temperature ranges.

4 *Pad or ball finish code is per IPC/JEDEC J-STD-609. Recommended LGA and BGA PCB Assembly and Manufacturing Procedures LGA and BGA Package and Tray DrawingsLT31203 Rev. 0 For more information CHARACTERISTICS The l denotes the specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25 C. VIN = PVIN = 12V, PVOUT = 5V unless otherwise Operating Voltage After Start-Up (Note 4) 26V VOutput Operating Undervoltage Lockout ThresholdVCC Rising VCC Fallingl l VVCC Undervoltage Lockout Hysteresis100mVInput Current in ShutdownEN/UVLO = 0V3 AInput Current in Sleep FB = 30 AOscillator FrequencyRT = l90010001100kHzOscillator Frequency Rangel4002000kHzSYNC/MODE Frequency Rangel4002000kHzSYNC/MODE Logic Minimum Pulse WidthMinimum Low or High Duration100nsSoft-Start Duration6msFeedback Voltage l787 779795 795803 811V VFB Pin Input Current150nAError Amplifier Transconductance120 sEN/UVLO Pin Input Logic Pin Comparator ThresholdRising Rising.

5 40 C TJ 125 VEN/UVLO Pin Hysteresis Current250nAEN/UVLO Pin Hysteresis Voltage90mVPROG Pin CurrentVISP VISN = 25mV VISP VISN = 1850 22 A APROG Pin Thresholdl779795811 VMPPC Pin Thresholdl774795822 VPGOOD ThresholdPercent of FB Voltage Fallingl 8 HysteresisPercent of FB Pull-Down Resistance100250 PGOOD LeakageVPGOOD = 24V140nAInductor Current LimitLimit on Average (Not Peak) Inductor Mode Inductor Current LimitLimit on Average (Not Peak) Inductor Current1 AMaximum Duty CyclePercentage of Period SW2 is Low in Boost Mode, RT = (Note 4)l9195%SW1, SW2 Minimum Low Time(Note 4)70nsLT31204 Rev. 0 For more information switch ResistanceSwitch A (PVIN to SW1) switch B (SW1 to PGND) switch C (SW2 to PGND) switch D (SW2 to PVOUT)25 23 23 25m m m m N-Channel switch Leakage PVIN = PVOUT = 24V; SW1 = SW2 = 0V110 AVCC Regulation Dropout VoltageICC = 50mA, VIN = Current Limit100mAVCC Reverse CurrentVCC = 5V, VIN = 3V5 AELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25 C.

6 VIN = PVIN = 12V, PVOUT = 5V unless otherwise 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 LT3120J is guaranteed to meet performance specifications over the 40 C to 150 C operating junction temperature ranges. High junction temperatures degrade operating lifetimes; operating lifetime is derated for junction temperatures greater than 125 3: Minimum input voltage is governed by the VCC UVLO threshold. If VCC is maintained through external bootstrapping, the part will continue to operate until power transfer to the output is no longer 4: switch timing measurements are made in an open-loop test configuration.

7 Timing in the application may vary somewhat from these values due to differences in the switch pin voltage during the non-overlap durations when switch pin voltage is influenced by the magnitude and direction of the inductor 0 For more information PERFORMANCE CHARACTERISTICSM aximum Reverse Current During MPPC Control (VMPPC < )Line RegulationLoad RegulationPower switch Resistance vs TemperaturePower switch Resistance vs VCCEN/UVLO Pin Hysteresis Current vs TemperatureEN/UVLO Pin Accurate Threshold vs TemperatureEN/UVLO Pin Logic Thresholds vs TemperatureEN/UVLO Pin Current vs EN/UVLO Pin VoltageLOAD = 1 ASYNC/MODE = HIGHINPUT VOLTAGE (V)258111417202326 IN VOUT (%)3120 G02 LOAD CURRENT (A)0123456 IN VOUT (%)3120 G03 TEMPERATURE ( C) 60 3003060901201502202252302352402452502552 60 HYSTERESIS CURRENT (nA)3120 G06 RISINGFALLINGTEMPERATURE ( C) 60 VOLTAGE (V)3120 G07 RISINGFALLINGTEMPERATURE ( C) 60 300306090120150450530610690770850 THRESHOLD VOLTAGE (mV)3120 G08 VOUT = 5 VfSW = 1 MHzINPUT VOLTAGE (V) CURRENT (mA)3120 G01 TEMPERATURE ( C) 60 300306090120150101622283440 switch RESISTANCE (m )3120 G04 VCC VOLTAGE (V) RESISTANCE (m )3120 G05 VOLTAGE (V)261014182226 1012345EN/UVLO PIN CURRENT ( A)3120 G09LT31206 Rev.

8 0 For more information PERFORMANCE CHARACTERISTICSVCC UVLO Threshold vs TemperatureOscillator Frequency vs RTOscillator Frequency vs VINO scillator Frequency vs TemperatureFB Voltage vs TemperaturePROG Pin Voltage vs TemperatureMPPC Pin Voltage vs TemperatureSW1, SW2 Minimum Low Time vs VCCRISINGFALLINGTEMPERATURE ( C) 60 VOLTAGE (V)3120 G10RT PIN RESISTOR (k ) FREQUENCY (MHz)3120 G11 TEMPERATURE ( C) 60 300306090120150 FROM 25 C (%)3120 G13 TEMPERATURE ( C) 60 300306090120150 FROM 25 C (%)3120 G14 TEMPERATURE ( C) 60 300306090120150 5 4 3 2 1012345 CHANGE FROM 25 C (%)3120 G16 VCC VOLTAGE (V) 20 1001020304050607080 CHANGE (%)3120 G17 INPUT VOLTAGE (V)258111417202326 FROM VIN = 12V (%)3120 G12 TEMPERATURE ( C) 60 300306090120150 FROM 25 C (%)3120 G15LT31207 Rev.

9 0 For more information PERFORMANCE CHARACTERISTICSE fficiency, VOUT = , fSW = 500kHzEfficiency, VOUT = , fSW = 1 MHzEfficiency, VOUT = , fSW = 2 MHzEfficiency, VOUT = 5V, fSW = 500kHzEfficiency, VOUT = 5V, fSW = 1 MHzEfficiency, VOUT = 5V, fSW = 2 MHzEfficiency, VOUT = 12V, fSW = 500kHzEfficiency, VOUT = 12V, fSW = 1 MHzEfficiency, VOUT = 12V, fSW = 2 MHzPWMB urst Mode OPERATIONVIN = = 5 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G18 PWMB urst Mode OPERATIONOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G19 VIN = = 5 VVIN = 12 VPWMB urst Mode OPERATIONVIN = = 5 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G20 PWMB urst ModeOPERATIONVIN = 3 VVIN = 5 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G21 PWMB urst Mode OPERATIONVIN = 3 VVIN = 5 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G22 PWMB urst Mode OPERATIONVIN = 3 VVIN = 5 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G23 PWMVIN = 5 VVIN = 15 VVIN = 12 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G24 Burst ModeOPERATIONPWMB urst Mode OPERATIONVIN = 5 VVIN = 12 VVIN = 15 VOUTPUT CURRENT (A)

10 100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G25 PWMB urst Mode OPERATIONVIN = 5 VVIN = 12 VVIN = 15 VOUTPUT CURRENT (A)100 1m 10m 100m 1 10102030405060708090100 EFFICIENCY (%)3120 G26LT31208 Rev. 0 For more information PERFORMANCE CHARACTERISTICSE fficiency, VOUT = 15V, fSW = 500kHzEfficiency, VOUT = 15V, fSW = 1 MHzEfficiency, VOUT = 15V, fSW = 2 MHzEfficiency, VOUT = 20V, fSW