LT3957A

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Rev. 0For more information www.analog.com Document Feedback TYPICAL APPLICATION FEATURES DESCRIPTION 28V, 5A Low IQ Synchronous Step-Up Silent Switcher with PassThru The LT®8337/LT8337-1 is a low I Q, synchronous step- up DC/DC converter . It features Silent Switcher architec- ture and optional spread spectrum frequency modula - tion (SSFM) to minimize EMI emissions while delivering high efficiencies at high switching frequencies. The wide input/output voltage range, low V IN pin quies- cent current in Burst Mode operation, and 100% duty- cycle capability for the synchronous MOSFET in PassThru operation (VIN > VOUT) makes the LT8337/LT8337-1 ide- ally suited for battery-powered systems and general pur- pose step-up applications. The LT8337/LT8337-1 integrates 28V, 5A power switches, operating at a fixed switching frequency programmable between 300kHz and 3MHz and synchronizable to an external clock. The LT8337/ LT8337-1 features output soft-start and output overvoltage lockout. The LT8337-1 allows external compensation via the VC pin for fast transient response. The LT8337 offers an output power good flag via the PG pin. High Efficiency 5V to 13V Input, 2MHz, 15V Output Boost Converter

APPLICATIONS

n Silent Switcher® Architecture n Ultralow EMI Emissions n Optional Spread Spectrum Frequency Modulation n Integrated 28V, 5A Power Switches n Wide Input Voltage Range: 2.7V to 28V n Output Voltage Programmable Up to 26V n Low VIN Pin Quiescent Current n 0.3µA in Shutdown n 4µA in Burst Mode® Operation (LT8337) n 15µA in PassThru™ (LT8337) n 100% Duty Cycle Capability for Synchronous MOSFET n External Compensation: Fast T ransient Response (LT8337-1) n Power Good Monitor (LT8337) n Adjustable and Synchronizable: 300kHz to 3MHz n Pulse-Skipping or Burst Mode Operation at Light Load n Small 16-Lead (3mm × 3mm) LQFN Package n Battery-Powered Systems n General Purpose Step-Up All registered trademarks and trademarks are the property of their respective owners. Protected by U.S patents, including 10686381. Efficiency OUTPUT CURRENT (mA) 0.1 100 1000 10000 100 0.1 100 1000 10000 EFFICIENCY (%) POWER LOSS (mW)

83371 TA01b

VIN = 13V VIN = 5V INTVCC SYNC/MODE PG VIN SW BST EN/UVLO FB GND VOUT L T8337

83371 TA01a

1.2A AT 5V VIN 3A AT 13V VIN 22µF 2.2µH 0.1µF 22µF 71.5k 1µF 47.5k 2MHz

Rev. 0 For more information www.analog.com PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS P Operating Junction Temperature Range (Notes 2, 3) LT8 125°C LT8 C to 150°C Maximum Reflow (Package Body) (Note 1) ORDER INFORMATION PART NUMBER PART MARKING PAD FINISH PACKAGE* TYPE MSL RATING TEMPERATURE RANGE (SEE NOTE 2)DEVICE FINISH CODE LT8337EV#PBF LHKR e4 Au (RoHS) LQFN (Laminate Package with QFN Footprint) –40°C to 125°C LT8337JV#PBF –40°C to 150°C LT8337EV-1#PBF LHNW –40°C to 125°C LT8337JV-1#PBF –40°C to 150°C

Contact the factory for parts specified with wider operating temperature ranges. Pad or ball finish code is per IPC/JEDEC J-STD-609. *The LT8337/LT8337-1 package has the same dimensions as a standard 3mm × 3mm QFN.
Recommended LGA and BGA PCB Assembly and Manufacturing Procedures
LGA and BGA Package and Tray Drawings LT8337 LT8337-1 16 15 14 13 5 6 7 8 TOP VIEW LQFN PACKAGE 16-LEAD (3mm × 3mm) LQFN θJA = 42.8°C/W, θJCtop = 45.2°C/W , θJCbottom = 8.2°C/W (NOTE 4) EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB 1SYNC/MODE RT GND FB BST SW SW SW GND VOUT VOUT GND PG INTV CC EN/UVLO VIN NC NC NC NC GND 16 15 14 13 5 6 7 8 TOP VIEW LQFN PACKAGE 16-LEAD (3mm × 3mm) LQFN θJA = 42.8°C/W, θJCtop = 45.2°C/W , θJCbottom = 8.2°C/W (NOTE 4) EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB 1SYNC/MODE RT GND FB BST SW SW SW GND VOUT VOUT GND VC INTVCC EN/UVLO VIN NC NC NC NC GND

Rev. 0For more information www.analog.com PARAMETER CONDITIONS MIN TYP MAX UNITS VIN Operation Voltage l 2.7 28 V VIN Quiescent Current in Shutdown EN/UVLO = 0.15V EN/UVLO = 0.15V l 0.3 0.3 µA µA LT8337 V IN Quiescent Current SYNC/MODE = 0V, Not Switching 4 8 µA SYNC/MODE = Open, Not Switching 0.9 1.5 mA VIN = 10.1V, VOUT = 10V, FB = 1.05V (In PassThru Mode) 15 25 µA LT8337-1 VIN Quiescent Current SYNC/MODE = 0V, Not Switching 23 35 µA SYNC/MODE = Open, Not Switching 0.9 1.5 mA VIN = 10.1V, VOUT = 10V, FB = 1.05V (In PassThru Mode) 30 60 µA FB Regulation Voltage E-Grade J-Grade l l 0.994 0.983 0.980 1.000 1.000 1.000 1.006 1.010 1.012 V V V FB Line Regulation 2.7V < V IN < 28V l 0.005 0.03 %/V FB Pin Input Current FB = 1.0V –20 20 nA Switching Frequency RT = 357kΩ RT = 102kΩ RT = 47.5kΩ RT = 30.1kΩ l 270 0.93 1.85 2.7 300 330 1.07 2.15 3.3 kHz MHz MHz MHz Spread Spectrum Modulation Frequency as Percentage of f SW 0.45 % Spread Spectrum Modulation Frequency Range as Percentage of f SW 20 % Synchronizable Frequency SYNC/MODE = External Clock l 0.3 3 MHz SYNC/MODE Pin Input Logic Level for Frequency Synchronization SYNC Logic Low SYNC Logic High l l 1.7 0.4 V V Soft-Start Time RT = 47.5kΩ 1.4 ms EN/UVLO Threshold Voltage Falling Hysteresis l 0.94 1.0 1.06 V mV EN/UVLO Input Bias Current EN/UVLO = 2V –40 40 nA LT8337 PG Upper Threshold Offset from Regulated FB FB Falling Hysteresis l 5 8 12 % LT8337 PG Lower Threshold Offset from Regulated FB FB Rising Hysteresis l –12 –8 LT8337 PG Leakage Current PG = 3.5V –40 40 nA LT8337 PG Pull-Down Resistance PG = 0.1V 700 2000 Ω LT8337-1 Error Amp T ransconductance V C = 1.25V 0.4 mS LT8337-1 Error Amp Gain 400 V/V LT8337-1 VC Source Current FB = 0.8V, VC = 1.25V –75 μA LT8337-1 VC Sink Current FB = 1.2V, VC = 1.25V 70 μA LT8337-1 VC Pin to Switch Current Gain 6.0 A/V ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 5V, EN/UVLO = 2V, unless otherwise noted.

Rev. 0 For more information www.analog.com ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 5V, EN/UVLO = 2V, unless otherwise noted. Note 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 lifetime. Note 2: The LT8337EV/LT8337EV-1 are guaranteed to meet performance specifications from the 0°C to 125°C junction temperature. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LT8337JV/LT8337JV-1 are 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 de-rated for junction temperatures greater than 125°C. Note 3: These ICs include overtemperature protection that is intended to protect the device during momentary overload conditions. The maximum rated junction temperature will be exceeded when this protection is active. Continuous operation above the specified absolute maximum operating junction temperature may impair device reliability or permanently damage the device. Note 4: θ values are determined by simulation per JESD51 conditions. PARAMETER CONDITIONS MIN TYP MAX UNITS Bottom Switch On-Resistance ISW = 1A 32 mΩ Bottom Switch Current Limit l 5 6 6.6 A Bottom Switch Minimum Off-time 20 50 ns Bottom Switch Minimum On-time V IN = 9.5V, VOUT = 10V 20 80 ns Top Switch On-Resistance ISW = 1A 35 mΩ SW Leakage Current VOUT = 28V, SW = 0V, 28V –1.5 1.5 μA VOUT Pin Current SYNC/MODE = 0V, VOUT = 10V, Not Switching 1 μA VIN = 10.1V, VOUT = 10V , FB = 1.05V (In PassThru Mode) 30 μA PassThru Mode VIN to VOUT Threshold (VIN – VOUT) VIN Rising VIN Falling –0.6 V V PassThru Mode Top Switch Reverse Current Limit VIN = 9.9V, VOUT = 10V, FB = 1.05V (Top Switch Turns Off) 1.5 A Efficiency and Power Loss vs Output Current Efficiency and Power Loss vs Output Current Burst Mode Efficiency vs Inductor Value INDUCTOR VALUE (/uni03BCH) 100 EFFICIENCY (%)

83371 G03

ILOAD = 10mA 1.0/uni03BCH: COILCRAFT XGL4020-102ME 1.5/uni03BCH: COILCRAFT XGL4020-152ME 2.2/uni03BCH: COILCRAFT XEL5030-222ME 4.7/uni03BCH: COILCRAFT XAL5030-472ME VIN = 13V VIN = 5V OUTPUT CURRENT (mA) 0.1 100 1000 10000 100 0.1 100 1000 10000 EFFICIENCY (%) POWER LOSS (mW)

83371 G01

VIN = 13V VIN = 5V FRONT PAGE CIRCUIT FRONT PAGE CIRCUIT VIN = 7.2V OUTPUT CURRENT (mA) 100 1000 100 0.1 100 1000 10000 EFFICIENCY (%) POWER LOSS (mW)

83371 G02

TYPICAL PERFORMANCE CHARACTERISTICSTA ≈ TJ = 25°C, unless otherwise noted.

Rev. 0For more information www.analog.com TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Output Current at Different Switching Frequencies EN/UVLO Thresholds vs Temperature FB Regulation Voltage vs Temperature Oscillator Frequency vs Temperature Oscillator Frequency with Spread Spectrum Modulation Switching Waveforms, Soft-Start T A ≈ TJ = 25°C, unless otherwise noted. EN/UVLO RISING EN/UVLO FALLING TEMPERATURE (C°) –50 –25 100 125 150 0.98 1.00 1.02 1.04 1.06 1.08 1.10 1.12 EN/UVLO THRESHOLD (V) Temperature

83371 G05

TEMPERATURE (°C) –50 –25 100 125 150 0.99 0.992 0.994 0.996 0.998 1.002 1.004 1.006 1.008 1.01 FB REGULATION VOL TAGE (V)

83371 G06

VIN = 7.2V FRONT PAGE CIRCUIT 15V LOAD CURRENT (mA) 0.1 100 1000 100 EFFICIENCY (%)

83371 G04

1MHz, L = 4.7/uni03BCH 2MHz, L = 2.2/uni03BCH 3MHz, L = 1.5/uni03BCH FRONT PAGE CIRCUIT VIN = 7.2V TEMPERATURE (°C) –50 –25 100 125 150 1.9 1.92 1.94 1.96 1.98 2.02 2.04 2.06 2.08 2.1 OSCILLATOR FREQUENCY (MHz)

83371 G07

RT = 47.5kΩ SYNC/MODE = OPEN TIME (/uni03BCs) OSCILLATOR FREQUENCY (MHz)

83371 G08

1.9 2.1 2.0 2.2 2.3 2.4 2.5 RT = 47.5kΩ SYNC/MODE = INTVCC Switching Waveforms, Soft-Start at Different V IN Voltages Bottom Switch Current Limit vs Temperature Bottom Switch Current Limit vs Duty Cycle TEMPERATURE (°C) –50 –25 100 125 150 5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 CURRENT LIMIT (A)

8337 G11

DUTY CYCLE (%) 100 5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 CURRENT LIMIT (A)

83371 G12

83371 G10

VIN = 13V FRONT PAGE CIRCUIT VOUT AT VIN = 13V VOUT AT VIN = 9V VOUT AT VIN = 5V

Rev. 0 For more information www.analog.com TYPICAL PERFORMANCE CHARACTERISTICS TA ≈ TJ = 25°C, unless otherwise noted. Switching Waveforms, Current Limit at 15% Duty Cycle Switching Waveforms, Current Limit at 82% Duty Cycle Power Switch Voltage Drop vs Switch Current Power Switch Voltage Drop vs Temperature LT8337-1 T ransient Response, Pulse-Skipping Mode Operation LT8337-1 T ransient Response, Burst Mode Operation TOP SWITCH BOTTOM SWITCH SWITCH CURRENT (A) 120 150 180 210 240 SWITCH DROP (mV) Switch Current

83371 G15

SWITCH CURRENT = 1A TEMPERATURE (C°) –50 –25 100 125 150 SWITCH DROP (mV) Switch Current

83371 G16

83371 G13

VIN = 13V FRONT PAGE CIRCUIT 500ns/DIV

83371 G14

VIN = 2.8V FRONT PAGE CIRCUIT V IN = 7.2V FRONT PAGE CIRCUIT 200µs/DIV V OUT 0.2V/DIV I OUT 1A/DIV

83371 G17

V IN = 7.2V FRONT PAGE CIRCUIT 200µs/DIV V OUT 0.2V/DIV I OUT 1A/DIV

83371 G18

V IN (V) 2.70 2.75 2.80 2.85 2.90 2.95 3.00 0.5 1.0 1.5 2.0 2.5 3.0 3.5 MAX SWITCHING FREQUENCY (MHz) Frequency vs Input Voltage

83371 G19

V IN = 7.2V FRONT PAGE CIRCUIT WITH L T8337-1 C C = 220pF , R C = 100k 200µs/DIV V OUT 0.2V/DIV I OUT 1A/DIV

83371 G20

V IN = 7.2V FRONT PAGE CIRCUIT WITH L T8337-1 C C = 220pF , R C = 100k 200µs/DIV V OUT 0.2V/DIV I OUT 1A/DIV

83371 G21

LT8337 T ransient Response, Pulse-Skipping Mode Operation LT8337 T ransient Response, Burst Mode Operation Max Programmable Switching Frequency vs Input Voltage

Rev. 0For more information www.analog.com TYPICAL PERFORMANCE CHARACTERISTICS Minimum On/Off Times vs Temperature Switching Waveforms, Full Frequency PWM Operation Switching Waveforms, Continuous Burst Mode Operation Switching Waveforms, Discontinuous Burst Mode Operation Switching Waveforms, Light Load Low I Q Burst Mode Operation Switching Waveforms, Discontinuous Pulse-Skipping Mode T A ≈ TJ = 25°C, unless otherwise noted. TEMPERATURE (°C) –50 –25 100 125 150 MIN ON/OFF TIMES (ns)

83371 G22

VOUT = 30V 2/uni03BCs/DIV

83371 G23

VIN = 5V ILOAD = 1.2A FRONT PAGE CIRCUIT 2/uni03BCs/DIV

83371 G24

VIN = 5V ILOAD = 250mA FRONT PAGE CIRCUIT 5/uni03BCs/DIV

83371 G25

VIN = 5V ILOAD = 50mA FRONT PAGE CIRCUIT 10ms/DIV

83371 G26

VIN = 5V ILOAD = 0mA FRONT PAGE CIRCUIT 500ns/DIV

83371 G27

0.5A/DIV VSW 10V/DIV VIN = 7.2V ILOAD = 10mA FRONT PAGE CIRCUIT Waveforms, PassThru Mode Operation Waveforms, Reverse Current Protection in PassThru Mode Switching Waveforms, Frequency Foldback when V IN is close to VOUT 5/uni03BCs/DIV VOUT , VIN 1V/DIV IL 1A/DIV VSW 20V/DIV ILOAD = 1A VIN = 15.5V FRONT PAGE CIRCUIT VIN VOUT

83371 G28

VOUT , VIN 1V/DIV IL 2A/DIV VSW 20V/DIV FRONT PAGE CIRCUIT VOUT VIN –1.6A 15.6V 200mA

83371 G29

VOUT , VIN 1V/DIV IL 1A/DIV VSW 20V/DIV ILOAD = 1A FRONT PAGE CIRCUIT VOUT VIN 15V

83371 G30

Rev. 0 For more information www.analog.com Conducted EMI Performance (CISPR25 Class 5 Peak) TYPICAL PERFORMANCE CHARACTERISTICSTA ≈ TJ = 25°C, unless otherwise noted. Radiated EMI Performance (CISPR25 Class 5 Peak) CLASS 5 PEAK LIMIT L T8337 AMBIENT FREQUENCY (MHz) 0.1 108 –20 –10 PEAK CE (dBµV)

83371 G31

PAGE 20 CIRCUIT , 5V INPUT TO 12V OUTPUT AT 1.5A, SSFM = ON, f SW = 2MHz TO 2.4MHz CLASS 5 AVERAGE LIMIT L T8337 AMBIENT FREQUENCY (MHz) 0.1 108 –20 –10 AVERAGE CE (dBµV) CISPR25 Conducted Emission Performance Voltage Method

83371 G32

PAGE 20 CIRCUIT , 5V INPUT TO 12V OUTPUT AT 1.5A, SSFM = ON, f SW = 2MHz TO 2.4MHz CLASS 5 PEAK LIMIT L T8337 AMBIENT FREQUENCY (MHz) 0.1 100 1000 –20 –10 PEAK RE (dBµV/m) CISPR25 Radiated EMI Performance

83371 G33

PAGE 20 CIRCUIT , 5V INPUT TO 12V OUTPUT AT 1.5A, SSFM = ON, f SW = 2MHz TO 2.4MHz CLASS 5 AVERAGE LIMIT L T8337 AMBIENT FREQUENCY (MHz) 0.1 100 1000 –20 –10 AVERAGE RE (dBµV/m)

83371 G34

PAGE 20 CIRCUIT , 5V INPUT TO 12V OUTPUT AT 1.5A, SSFM = ON, f SW = 2MHz TO 2.4MHz Conducted EMI Performance (CISPR25 Class 5 Average) Radiated EMI Performance (CISPR25 Class 5 Average)

Rev. 0For more information www.analog.com PIN FUNCTIONS SYNC/MODE (Pin 1): External Synchronization Input and Mode Selection Pin. This pin allows five selectable modes for optimization of performance: SYNC/MODE PIN INPUT CAPABLE MODE(S) OF OPERATION (1) GND or <0.1V Burst (2) 50k Resistor to GND Burst/SSFM (3) Float (Pin Open) Pulse-Skipping (4) INTVCC or > (INTVCC–0.2V) Pulse-Skipping/SSFM (5) External Clock Pulse-Skipping/Sync where the selectable modes of operation are: Burst = low IQ, (low output ripple operation at light loads) Pulse-Skipping = skipped pulse(s) at light load (aligned clock) SSFM = spread spectrum frequency modulation for low EMI Sync = switching frequency synchronized to external clock. The LT8337/LT8337-1 automatically selects pulse-skip- ping mode with no spread spectrum frequency modu- lation during start-up, and The SYNC/MODE pin input configurations (1) through (4) are ignored. The LT8337/LT8337-1 automatically select low IQ opera- tion in the PassThru mode operation, and all the SYNC/ MODE pin input configurations are ignored. RT (Pin 2): Switching Frequency Adjustment Pin. The LT8337/LT8337-1 switching frequency is programmed by connecting a resistor of the appropriate value from the RT pin to GND at Pin 3. See the Applications Information section for more detail. Do not leave the RT pin open. GND (Pins 3, 5, 8, Exposed Pad Pin 17): Ground. The exposed pad should be soldered to the PCB ground plane for good thermal and electrical performance. See the Applications Information section for sample layout. FB (Pin 4): Feedback Input Pin. This pin receives the feed- back voltage from the external resistor divider between VOUT and Pin 3 GND. FB pin is one input to the error amplifier of the output voltage control loop. See the Applications Information section for sample layout. V OUT (Pins 6, 7): Output Pins. Connect one 1µF capaci - tor between VOUT at Pin 6 and GND at Pin 5 only, and a matching 1µF capacitor between VOUT at Pin 7 and GND at Pin 8 only. These two capacitors complete the Silent Switcher configuration and must be placed as close to the IC as possible to achieve lowest EMI. Additional bulk capacitors of 2.2µF or more should be placed close to the IC with the positive terminals connected to VOUT, and negative terminals connected to ground plane. See the Applications Information section for a sample layout. SW (Pins 9, 10, 11): The SW pins are the outputs of the internal power switches. Tie these pins together and connect them to the inductor and one side of the boost capacitor C BST . BST (Pin 12): Top Switch Gate Driver Supply Pin. Place a 0.1µF capacitor (C BST) between the BST and SW pins and close to the IC. VIN (Pin 13): Input Supply Pin. This pin must be con - nected to the input of the power stage (the inductor’s input terminal). EN/UVLO (Pin 14): Enable and Input Undervoltage Lockout Pin. The IC is shut down when this pin is below 1V (typical). The IC draws a low V IN current of 0.3μA (typical) when this pin is below 0.15V. The IC is enabled when this pin is above 1.0V (typical). A resistor divider from V IN to GND can be used to program a VIN threshold below which the IC is shut down. See the Applications Information section for further details. Tie EN/UVLO to VIN if the shutdown feature is not used. INTVCC (Pin 15): Internal 3.5V Regulator Bypass Pin. This pin provides supply for internal drivers and control circuits. The bypass capacitor for INTV CC should be con- nected to the ground plane. Do not load the INTV CC pin with external circuitry. This pin must be bypassed with a 1µF or larger low ESR ceramic capacitor placed close to the pin. PG (Pin 16, LT8337 Only): Power Good Indicator . Open- drain logic output that is pulled to ground when the output voltage is greater than ± 8% outside the regulated volt - age. PG is also pulled to ground when EN/UVLO is below 1V, INTVCC has fallen too low, or the IC enters thermal shutdown. V C (Pin 16, LT8337-1 Only): Error Amplifier Output and Switch Regulator Compensation Pin. Connect this pin to appropriate external RC network to compensate the regu- lator loop frequency response.

Rev. 0 For more information www.analog.com BLOCK DIAGRAM RT RTVC RC CC OSC SYNC/MODE1216 SS – + VC FB SYNC/MODE OSC VC SHDN SS EA INTVCC FB SHDN VOUT (6, 7) COUT1,2 COUT3 VOUT INTVCC CVCC 1215 CIN VIN VIN R4 R3 – + GND (3, 5, 8, 17) 83371 BD FB BST CBST SW (9, 10, 11) ILL EN/UVLO UVLO OSCILLATOR RAMP GENERATOR VIN_HIGH I_ZERO VOUT_OVLO BURST MODE DETECT SWITCHING LOGIC AND CHARGE PUMP 3.5V REG AND UVLO 1V REF TJ > 170°C ±8% PG16 FB INTVCC SHDN A6 VIN 28V VIN_HIGH I_ZERO VOUT_OVLO L T8337 ONL Y L T8337 ONL Y L T8337-1 ONL Y

Rev. 0For more information www.analog.com OPERATION The LT8337/ LT8337-1 uses a fixed frequency, current mode control scheme to provide excellent line and load regulation. Referring to the Block Diagram, the Switching Logic and Charge Pump block turns on the power switch M1 through driver G1 at the start of each oscillator cycle. During the M1 switch on-phase, the inductor current I L flows through M1. A current proportional to the M1 switch current is added to a stabilizing slope compensation ramp and the resulting sum is fed into the positive terminal of the PWM comparator A1. The voltage at the negative input of A1, labeled “V C”, is set by the error amplifier EA and is an amplified version of the difference between the feedback voltage FB and the reference voltage. During the M1 on-phase, I L increases. When the signal at the positive input of A1 exceeds VC, A1 sends out a signal to the Switching Logic and Charge Pump block to turn off M1. When M1 turns off, the synchronous power switch M2 turns on until the next clock cycle begins or induc - tor current I L falls to zero. During the M1 off-phase, I L decreases. Through this repetitive action, the EA sets the correct I L peak current level to keep the output in regula- tion. VIN and V OUT are constantly monitored by the IC. When VIN rises above V OUT (causing A3’s output high) and at the same time V OUT is higher than its regulation voltage programmed by the FB resistor network, the IC enters PassThru operation, where M2 is kept on continu- ously and M1 is kept off continuously, and the V OUT is essentially shorted to V IN by the inductor and M2. See Applications Information section for further details. The IC features Silent Switcher architecture to minimize EMI emissions while delivering high efficiency. The Silent Switcher EMI cancellation loops are completed by placing one 1µF capacitor between VOUT at pin 6 and GND at pin 5 and a matching 1µF capacitor between VOUT at pin 7 and GND at pin 8 (see Applications Information section for further details). The EN/UVLO pin controls whether the IC is enabled or is in shutdown state. A 1.0V reference and a comparator A2 with 90mV hysteresis (Block Diagram) allow the user to accurately program the supply voltage at which the IC turns on and off. See the Applications Information section for further details. The LT8337/ LT8337-1 features a variety of operation modes which can be selected by SYNC/MODE pin to opti- mize the converter performance based on the application requirements. The low ripple Burst Mode operation can be selected to optimize the efficiency at light loads. The spread spectrum frequency modulation function can be selected to minimize the EMI emissions. Pulling SYNC/MODE pin to ground selects Burst Mode operation. Connecting this SYNC/MODE to ground through a 50k resistor selects Burst Mode operation with spread spectrum frequency modulation. Floating SYNC/ MODE pin selects pulse-skipping operation. Connecting SYNC/MODE pin to INTV CC selects pulse-skipping oper- ation with spread spectrum frequency modulation. If a clock is applied to the SYNC/MODE pin, the IC synchro - nizes to an external clock frequency and operates in pulse- skipping mode. See the Applications Information section for further details.

Rev. 0 For more information www.analog.com APPLICATIONS INFORMATION Light Load Current Operation—Burst Mode Operation or Pulse-Skipping To enhance the efficiency at light loads, the LT8337/ LT8337-1 features operate in low ripple Burst Mode operation. When the IC is enabled for Burst Mode opera- tion, the minimum peak inductor current is set to approxi- mately 1.2A even though the V C node Block Diagram) indicates a lower value. In this condition, the IC maintains the output regulation voltage by reducing the switching frequency instead of reducing the inductor peak current. In light load Burst Mode operation the IC delivers single pulses of current to the output capacitor followed by sleep periods during which the output power is supplied by the output capacitor . This low ripple Burst Mode opera- tion minimizes the input quiescent current and minimizes output voltage ripple. As the output load decreases, the frequency of single cur- rent pulses decreases and the percentage of time the IC is in sleep mode increases, resulting in much higher light load efficiency than for typical converters. By maximizing the time between pulses, the converter V IN pin quiescent current approaches 4µA (LT8337) or 23µA ( LT8337-1) for a typical application when there is no output load. To optimize the quiescent current performance at light loads, the current in the feedback resistor divider should be minimized as it appears to the output as load current. In order to achieve higher light load efficiency, more energy should be delivered to the output during the single small pulses in Burst Mode operation such that the IC can stay in sleep mode longer between each pulse. This can be achieved by using a larger value inductor . For example, while a smaller inductor value would typically be used for a high switching frequency application, if high light load efficiency is desired, a larger inductor value should be chosen. See the Burst Mode Efficiency vs Inductor Value curve in the Typical Performance Characteristics section for more information. Programming V IN Turn-On and Turn-Off Thresholds with the EN/UVLO Pin The falling threshold voltage and rising hysteresis voltage of the EN/UVLO pin can be calculated by Equation 1. VVIN,FALLING = 1.0V • (R3 + R4) VVIN,RISING = 90mV • (R3 + R4) R4 + VVIN,FALLING (1) When in Burst Mode operation with light load currents, the current through the resistor network R3 and R4 can easily be greater than the supply current consumed by the IC. Therefore, large resistors can be used for R3 and R4 to minimize their effect on efficiency at light loads. EN/UVLO pin can be tied to V IN if the shutdown feature is not used, or alternatively, the pin may be tied to a logic level if shutdown control is required. The IC draws a low V IN quiescent current of 0.3µA (typical) When EN/UVLO is below 0.15V. INTVCC Regulator An internal low dropout (LDO) regulator produces the 3.5V supply from V IN that powers the drivers and the internal bias circuitry. The INTVCC pin must be bypassed to ground with a minimum of 1μF ceramic capacitor . Good bypassing is necessary to supply the high tran - sient currents required by the power MOSFET gate driv- ers. Applications with high VIN voltage and high switching frequency increase die temperature because of the higher power dissipation across the LDO. When VIN is lower than 2.95V for LT8337 or 2.90V for LT8337-1, the maximum programmable switching frequency is lower due to the voltage drop across the LDO. See the Max Programmable Switching Frequency vs Input Voltage curve in the Typical Performance Characteristics section for more informa - tion. Do not connect an external load to the INTVCC pin.

as lower audio noise and RF interference. frequency operation requires a physically larger inductor . Table 1. SW Frequency (fSW) vs RT Value as close as possible to the SYNC pulse frequency. Figure 1. RT Value vs Switching Frequency

83371 F01

Rev. 0 For more information www.analog.com Spread Spectrum Frequency Modulation The LT8337/ LT8337-1 features spread spectrum fre - quency modulation to further reduce EMI emissions. The user can select spread spectrum frequency modulation with Burst Mode operation by connecting the SYNC/MODE pin to ground through a 50k resistor , or spread spectrum frequency modulation with pulse-skipping operation by connecting the SYNC/MODE pin to INTV CC. When spec- trum frequency modulation is selected, a stepped trian - gular frequency modulation is used to vary the internal oscillator frequency between the value programmed by the RT resistor to approximately 20% higher than that value. The modulation frequency is approximately 0.45% of the switching frequency. For example, when the IC is programmed to 2MHz, and spread spectrum frequency modulation is selected, the oscillator frequency var - ies from 2MHz to 2.4MHz at a 9kHz rate (see Oscillator Frequency with Spread Spectrum Modulation curve in the Typical Performance Characteristics section). When oper- ating at light load, the spread spectrum frequency modu- lation is more effective in pulse-skipping mode than in Burst Mode operation, due to the fact that pulse-skipping operation maintains the programmed switching frequency down to a much lower load current as compared to Burst Mode operation. V IN to VOUT PassThru Mode Operation In the boost pre-regulator applications for automotive stop-start and cold crank, VIN is normally above the regu- lated VOUT voltage. In this condition, LT8337/LT8337-1 enters PassThru operation. LT8337/LT8337-1 is designed to have an accurate, well controlled PassThru operation with low quiescent current consumption. If VIN transiently falls below the V OUT regulation setpoint, the boost con - verter commences switching to maintain the output volt- age in regulation. As shown in Block Diagram, VIN is compared with V OUT using the comparator A3 with 0.6V hysteresis. When VIN rises above VOUT (causing A3’s output high), and at the same time VOUT is higher than its regulation voltage programmed by the FB resistor network, the IC boost converter enters PassThru operation, where the synchro- nous power switch M2 is kept on continuously and the power switch M1 is kept off continuously. The voltage across the boost capacitor (CBST), VBST_SW, is constantly monitored. When V BST_SW drops below 3.2V, an inter - nal charge pump is turned on to charge V BST_SW up to 3.6V, and then turned off. In PassThru mode the VOUT is essentially shorted to V IN by the inductor and M2, and VIN pin quiescent current is limited to 15µA ( LT8337) or 30µA (LT8337-1) regardless of the SYNC/MODE pin’s configuration. V OUT pin draws 30µA (typ). A typical waveforms drawing is shown in the Typical Performance Characteristics section. Several conditions cause the IC to exit from the PassThru mode operation. First, when VOUT drops below its regula- tion voltage programmed by the FB resistor network, the IC exits from PassThru mode operation and normal boost switching operation resumes to maintain the regulated VOUT voltage. Second, when V OUT is still higher than its regulation voltage but VIN drops below VOUT by the com- parator A3’s hysteresis of 0.6V (typ) or more to cause A3’s output low, M2 is turned off to prevent the reverse current from V OUT to VIN from ramping up. IC is back to the PassThru mode when A3’s output is high again. Third, when VOUT is still higher than its regulation voltage but M2’s reverse current (flowing from its drain to source) rises above 1.5A (typ), M2 is turned off to prevent the reverse current from V OUT to VIN from ramping up. The IC re-enters the PassThru mode when A3’s output is high again. Waveforms for typical reverse current protection are shown in the Typical Performance Characteristics section. To ensure the PassThru mode operation works properly, the IC’s VIN pin must be connect to the input of the power stage (the input terminal of inductor as shown in Block Diagram). APPLICATIONS INFORMATION

Rev. 0For more information www.analog.com FB Resistor Network and the Quiescent Current at No Load The output voltage is programmed with a resistor divider between the output and the FB pin. Choose the resistor values according to Equation 2. R1 = R2 • VOUT 1V – 1⎛ ⎝⎜ ⎞ (2) Reference designators refer to Block Diagram. The 1% resistors are recommended to maintain output voltage accuracy. If low input quiescent current and good light-load effi - ciency are desired, use large resistor values for the FB resistor divider . The current flowing in the divider acts as a load current, and will increase the no load input current to the converter . When VIN < VOUT, the LT8337 converter Burst Mode quies- cent current at no load can be estimated using Equation 3, and the LT8337-1 converter Burst Mode quiescent current at no load can be estimated using Equation 4. I ≈ VOUT R1 + R2 4µA 1µA+ + VOUT VIN 1.2 • •Q (3) I ≈ VOUT R1 + R2 23µA 1µA+ + VOUT VIN 1.4 • •Q (4) where 4µA and 23µA are the VIN pin quiescent current of the LT8337 and LT8337-1 respectively, and the second term is the current drawn by the feedback divider and VOUT pin (1μA) reflected to the input of the boost operating. For a 12V input, 24V output boost converter with R1 = 1M and R2 = 43.2k, it can be calculated that the LT8337 con- verter draws approximately 60µA from the supply at no load, and the LT8337-1 converter draws approximately 90µA from the supply at no load. Note that Equation 3 and Equation 4 imply that the no load current is a func - tion of VIN. When VIN is higher than the regulated VOUT voltage, the IC enters PassThru operation and VOUT is essentially shorted to VIN by the inductor and M2. The converter quiescent current at no load can be estimated using Equation 5 for LT8337 and Equation 6 for LT8337-1. I ≈ VIN R1 + R2 45µA +Q (5) I ≈ VIN R1 + R2 60µA +Q (6) where 45µA and 60µA are is the sum of the V IN pin and VOUT pin quiescent current of the LT8337 and LT8337-1 respectively, and the second term is the current drawn by the feedback divider . When using large FB resistors, a 4.7pF to 22pF phase-lead capacitor should be connected from V OUT to FB, and a careful evaluation of system stability should be made to ensure adequate design margin. Overvoltage Lockout The V OUT pin voltage is constantly monitored by the LT8337/LT8337-1. An overvoltage condition occurs when VOUT pin voltage exceeds approximately 28V. Switching is stopped at such condition. Normal switching is resumed when the VOUT pin voltage drops back to 28V or lower . Switching Frequency Foldback when V IN Approaches V OUT In some applications, VIN may rise to a voltage very close to VOUT . In this condition the switching regulator must operate at a very low duty cycles to keep VOUT in regula- tion. However , the minimum on-time limitation may pre- vent the switcher from attaining a sufficiently low duty cycle at the programmed switching frequency. As a result a typical boost converter may experience a large output ripple under these conditions. The LT8337 /LT8337-1 addresses this issue by adopting a switching frequency foldback function to smoothly decrease the switching frequency when its minimum on-time starts to limit the APPLICATIONS INFORMATION

Figure 3. A Simplified LT8337/LT8337-1 Power limiting the start-up peak switch currents. approximately given by Equation 7. circuit and limit the VOUT over-shoot as shown in Figure 3.

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Figure 2. Typical Start-Up Waveforms

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input voltage (Equation 10).

Rev. 0For more information www.analog.com Discontinuous conduction mode (DCM) provides higher conversion ratios at a given frequency at the cost of reduced efficiencies and higher switching currents. The inductor ripple current ∆ISW has a direct effect on the choice of the inductor value, the converter’ s maximum output current capability, and the light load efficiency in Burst Mode operation. Choosing smaller values of ∆I SW increases output current capability and light load effi - ciency in Burst Mode operation, but require large induc- tance values and reduce the current loop gain. Accepting larger values of ∆ISW provides fast transient response and allows the use of low inductance values, but results in higher input current ripple, greater core losses, lower light load efficiency in Burst Mode operation, and lower output current capability. Large values of ∆ISW at high duty cycle operation may result in sub-harmonic oscillation. ∆ISW = 1.2A to 2.4A generally provides a good starting value for many applications, and careful evaluation of system sta- bility should be made to ensure adequate design margin. Given an operating input voltage range, and having cho- sen the operating frequency and ripple current in the inductor , the inductor value of the boost converter can be determined using Equation 11. L = VIN(MIN) ∆ISW • fSW

DMAX (11) The peak inductor current is equal to the LT8337/ LT8337-1 bottom switch current limit as given in the Electrical Characteristics table. The user should choose an inductor with sufficient saturation and RMS current ratings to handle the inductor’s peak current. Input Capacitor Selection The input ripple current in a boost converter is relatively low (compared with the output ripple current), because this current is continuous. The voltage rating of the input capacitor , C IN, should comfortably exceed the maximum input voltage. Although ceramic capacitors can be rela- tively tolerant of overvoltage conditions, aluminum elec- trolytic capacitors are not. Be sure to characterize the APPLICATIONS INFORMATION input voltage for any possible overvoltage transients that could apply excess stress to the input capacitors. The value of C IN is a function of the source impedance, and in general, the higher the source impedance, the higher the required input capacitance. The RMS C IN ripple current can be estimated by Equation 12. IRMS(CIN) = 0.3 • ∆IL (12) Output Capacitor Selection The output capacitor has two essential functions. First, it filters the LT8337/LT8337-1’s discontinuous top switch current to produce the DC output. In this role, it deter - mines the output ripple, thus low impedance at the switch- ing frequency is important. The second function is to store energy in order to satisfy transient loads and stabilize the IC’s control loop. The X5R or X7R type ceramic capacitors have very low equivalent series resistance (ESR), which provides low output ripple and good transient response. T ransient performance can be improved with higher out- put capacitance and the addition of a feedforward capaci- tor placed between V OUT and FB. When a feedforward capacitor is used or output capacitance is adjusted, a careful evaluation of system stability should be made to ensure adequate design margin. Increasing the output capacitance will also decrease the output voltage ripple. Lower value of output capacitance can be used to save space and cost, but transient performance will suffer and loop instability may result. Besides the bulk output capacitors, two small output ceramic capacitors, 1µF each, should be placed as close as possible to the IC to complete the Silent Switcher can- cellation loops. See the Board Layout section for more detail. XR7 or X5R capacitors are recommended for best performance across temperature and output voltage variations. Note that larger output capacitance is required when a lower switching frequency is used. If there is significant induc- tance to the load due to long wires or cables, additional

to the Typical Applications section. and is typically pulled high with an external resistor . low, VIN under voltage, or thermal shutdown. output current proportional to the voltage at the V C pin. amplifier output current, resulting in two poles in the loop. frequency is much lower than the switching frequency. application with LT8337 which uses internal compensation. Figure 4. Mode for Loop Response

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pin or RT Pin (refer to Figure 6). Figure 5. T ransient Response Figure 6. A Recommended PCB Layout for the LT8337

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83317 F05b

Rev. 0 For more information www.analog.com Low IQ, Low EMI, 15V Output Boost Converter with SSFM L1: WURTH ELEKTRONIK 74438357015 L2: WURTH ELEKTRONIK 74479290125 FB1: WURTH ELEKTRONIK 742792040 * THE EMI PERFORMANCE IS SHOWN IN THE TYPICAL PERFORMANCE CHARACTERISTICS SECTION. VOUT 12V 1.5A 0.1µF 50V X7R 0.1µF 50V X7R OUTPUT EMI FIL TER FB1 22µF 25V X7R 1µF 50V X7R INTVCC SYNC/MODE PG VIN SW BST EN/UVLO FB GND VOUT L T8337

83371 TA02a

1.5µH 0.1µF 90.9k 1µF 47.5k 2MHz 4.7pF 49.9k 332k UVLOFALLING = 4V VIN 4.5V TO 10V 22µF 25V X7R 47µF 35V 10µF 25V X7R INPUT EMI FIL TER 0.25µH The exposed pad on the bottom of the package should be soldered to the ground plane to reduce the package thermal resistance. To keep the thermal resistance low, extend the ground plane as much as possible, and add many thermal vias to additional power ground planes within the circuit board. Thermal Considerations Care should be taken in the layout of the PCB to ensure good heat sinking of the LT8337/LT8337-1. The power ground plane should consist of large copper layers with thermal vias; these layers spread heat dissipated by the IC. Placing additional vias can reduce thermal resistance further . The maximum load current should be derated as the junction temperature approaches its maximum temperature rating. Power dissipation within the IC can APPLICATIONS INFORMATION be estimated by calculating the total power loss from an efficiency measurement and subtracting the inductor loss. The junction temperature can be calculated by multiply- ing the total IC power dissipation by the thermal resis- tance from junction to ambient and adding the ambient temperature. The IC includes internal overtemperature protection that is intended to protect the device during momentary overload conditions. The overtemperature protection shuts down the IC when the junction tem - perature exceeds 170°C (typ). The internal soft-start is triggered when the junction temperature drops below 165°C (typ). The maximum rated junction temperature is exceeded when this protection is active. Continuous operation above the specified absolute maximum operat- ing junction temperature (see Absolute Maximum Ratings section) may impair device reliability or permanently dam- age the device. TYPICAL APPLICATIONS

Rev. 0For more information www.analog.com TYPICAL APPLICATIONS 2.85V to 4.2V Input, 2MHz, 5V Output Boost Converter Efficiency vs Output Current LOAD CURRENT (mA) 0.01 0.1 100 1000 100 EFFICIENCY (%)

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VIN = 4.2V VIN = 3.6V VIN = 2.85V Burst Mode OPERATION L: COILCRAFT XGL4030-471ME VOUT 3A AT 3.6VIN 2A AT 2.85VIN 47µF 6.3V X7R 1µF 6.3V X7R INTVCC SYNC/MODE PG VIN SW BST EN/UVLO FB GND VOUT L T8337 RT L 0.47µH 0.1µF 249k 1µF 47.5k 2MHz 4.7pF 549k UVLOFALLING = 2.85V VIN 2.85V TO 4.2V 47µF 6.3V X7R

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5V to 15V Input, 2MHz, 12V Output Boost Converter Efficiency vs Output Current Efficiency vs Input Voltage VIN = 7.2V VIN = 5V OUTPUT CURRENT (mA) 0.1 100 1000 100 EFFICIENCY (%)

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I LOAD = 1.5A INPUT VOL TAGE (V) 100 EFFICIENCY (%)

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22µF 25V X7R 1µF 25V X7R INTVCC SYNC/MODE PG VIN SW BST EN/UVLO FB GND VOUT L T8337 RT L 1.5µH 0.1µF 90.9k 1µF 47.5k 2MHz 4.7pF 287k UVLOFALLING = 4.5V 22µF 25V X7R

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VOUT* 12V 1.2A AT 5V IN 2.2A AT 7.2VIN L: COILCRAFT XGL4020-152ME *WHEN V IN > 12V , VOUT FOLLOWS VIN. VIN 5V TO 15V

Rev. 0 For more information www.analog.com 2.8V to 24V Input, 18V Output Boost Converter Efficiency vs Output Current Efficiency vs Input Voltage TYPICAL APPLICATIONS LOAD CURRENT (mA) 0.1 100 1000 100 EFFICIENCY (%)

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VIN = 15V VIN = 9V VIN = 5V VIN = 2.8V Burst Mode OPERATION Burst Mode OPERATION I LOAD = 0.3A INPUT VOL TAGE (V) 100 EFFICIENCY (%) L: COILCRAFT XEL5030-472ME *WHEN VIN > 18V , VOUT FOLLOWS VIN 22µF 25V X7R 1µF 25V X7R INTVCC SYNC/MODE PG VIN SW BST EN/UVLO FB GND VOUT L T8337 RT L 4.7µH 0.1µF 59k 1µF 102k 1MHz 4.7pF 556k UVLOFALLING = 2.8V 22µF 25V X7R

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VOUT* 18V VIN 2.8V TO 24V

Rev. 0For more information www.analog.com Information furnished by Analog Devices is believed to be accurate and reliable. However , no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. PACKAGE DESCRIPTION 16-Lead (3mm × 3mm × 0.95mm) (Reference L TC DWG # 05-08-1798 Rev Ø) DETAIL B A PACKAGE TOP VIEW PIN 1 CORNER Y X aaa Z2× 16b PACKAGE BOTTOM VIEW

6 SEE NOTES

E D b 0.375 e e b DETAIL B SUBSTRATE MOLD CAP // bbb Z Z DETAIL C SUGGESTED PCB LAYOUT TOP VIEW 0.0000 0.0000 0.7500 0.2500 0.2500 0.7500 0.7500 0.2500 0.2500 0.7500 DETAIL A SEE NOTES PIN 1 NOTCH 0.23 × 45° 13 16 8 5 aaa Z 2× M X Y Z ccc MXY Z ccc M X Y Z eee M Zfff PACKAGE OUTLINE

0.25 REF

0.70 REF

3.50 ±0.05 3.50 ±0.05 LGA 16 0321 REV Ø TRAY PIN 1 BEVEL PACKAGE IN TRAY LOADING ORIENTATION COMPONENT PIN 1 L TXXXXX 0.385 0.385 0.385 0.385 DETAIL A ddd Z 16× SYMBOL A L b D E e aaa bbb ccc ddd eee fff MIN 0.85 0.30 0.22 NOM 0.95 0.40 0.25 3.00 3.00 1.43 1.43 0.50 1.05 0.03 0.50 0.28 0.10 0.10 0.10 0.10 0.15 0.08 NOTES SUBSTRATE THK MOLD CAP HT DIMENSIONS Z DETAIL C NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS 3. PRIMARY DATUM -Z- IS SEATING PLANE METAL FEATURES UNDER THE SOLDER MASK OPENING NOT SHOWN SO AS NOT TO OBSCURE THESE TERMINALS AND HEAT FEATURES DETAILS OF PIN 1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PIN 1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE

6 THE EXPOSED HEAT FEATURE MAY HAVE OPTIONAL CORNER RADII

7 CORNER SUPPORT PAD CHAMFER IS OPTIONAL

e L e/2 1.43 0.335 1.43 0.375 0.375 0.335

Rev. 0 For more information www.analog.com  ANALOG DEVICES, INC. 2021 www.analog.com RELATED PARTS TYPICAL APPLICATION PART NUMBER DESCRIPTION COMMENTS LT8330 1A (ISW), 60V, 2MHz High Efficiency Boost/SEPIC/ Inverting DC/DC Converter VIN = 3V to 40V, VOUT(MAX) = 60V, IQ = 6µA (Burst Mode Operation), ISD = <1µA, ThinSOT , 2mm × 3mm DFN Packages LT8331 0.5A (ISW), 140V, 500kHz High Efficiency Boost/ Flyback/SEPIC/Inverting DC/DC Converter VIN = 4.5V to 100V, VOUT(MAX) = 135V, IQ = 6µA (Burst Mode Operation), ISD = <1µA, MSOP-16(12)E LT3957A/ LT3957 Boost, Flyback, SEPIC and Inverting Converter with 5A/40V Switch 3V ≤ V IN ≤ 40V, Current Mode Control, 100kHz to 1MHz Programmable Operation Frequency, 5mm × 6mm QFN-36 Package LT3958 High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter with 3.5A/80V Switch 5V ≤ V IN < 80V, Current Mode Control, 100kHz to 1MHz Programmable Operation Frequency, 5mm × 6mm QFN-36 Package LT8335 28V, 2A, Low IQ Boost/SEPIC/Inverting 2MHz Converter VIN = 3V to 25V, VOUT(MAX) = 25V, IQ = 6µA (Burst Mode Operation), 3mm × 2mm LT8336 40V, 2.5A, Low IQ Synchronous Step-Up Silent Switcher VIN = 2.7V to 40V, VOUT(MAX) = 40V, IQ = 4μA (Burst Mode Operation), 3mm × 3mm LT8362 60V, 2A, Low IQ Boost/SEPIC/Inverting 2MHz Converter VIN = 2.8V to 60V, VOUT(MAX) = 60V, IQ = 9µA (Burst Mode Operation), MSOP-16(12)E, 3mm × 3mm DFN-10 Packages LT8364 60V, 4A, Low IQ Boost/SEPIC/Inverting 2MHz Converter VIN = 2.8V to 60V, VOUT(MAX) = 60V, IQ = 9µA (Burst Mode Operation), MSOP-16(12)E, 4mm × 3mm DFN-12 Packages LT8494 70V, 2A Boost/SEPIC 1.5MHz High Efficiency Step-Up DC/DC Converter VIN = 1V to 60V (2.5V to 32V Start-Up), VOUT(MAX) = 70V, IQ = 3µA (Burst Mode Operation), ISD = <1µA, 20-Lead TSSOP LT8580 1A (ISW), 65V 1.5MHz, High Efficiency Step-Up DC/DC Converter VIN: 2.55V to 40V, VOUT(MAX) = 65V, IQ = 1.2mA, ISD = <1µA, 3mm × 3mm DFN-8, MSOP-8E 8V to 16V Input, 24V Output Boost Converter Efficiency and Power Loss vs Output Current V IN = 16V V IN = 8V OUTPUT CURRENT (mA) 0.1 100 100 0.1 100 10k EFFICIENCY (%) POWER LOSS (mW) vs Output Current

83371 TA06b

L: COILCRAFT XEL5030-472ME 10µF 50V X7R 1µF 50V X7R INTVCC SYNC/MODE VC VIN SW BST EN/UVLO FB GND VOUT L T8337-1 RT L 4.7µH 0.1µF 43.2k 1µF 102k 1MHz 4.7pF 162k UVLOFALLING = 7.2V 10µF 50V X7R

83371 TA06a

1.2A AT 8V IN 2.4A AT 16VIN VIN 8V TO 16V 100k 220pF10pF

Summary

28V, 5A Low IQ Synchronous Step-Up Silent Switcher with PassThru

Description