LTC3788IGN-1#PBF Linear Technology, LTC3788IGN-1#PBF Datasheet
LTC3788IGN-1#PBF
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LTC3788IGN-1#PBF Summary of contents
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... PGOOD outputs, see the LTC3788 data sheet. L, LT, LTC, LTM, Linear Technology, OPTI-LOOP , Burst Mode and the Linear logo are registered trademarks and No R All other trademarks are the property of their respective owners. Protected Patents, including 5408150, 5481178, 5705919, 5929620, 6144194, 6177787, 6580258 ...
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... LEAD FREE FINISH TAPE AND REEL LTC3788EGN-1#PBF LTC3788EGN-1#TRPBF LTC3788IGN-1#PBF LTC3788IGN-1#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: ELECTRICAL CHARACTERISTICS junction temperature range, otherwise specifi ...
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ELECTRICAL CHARACTERISTICS junction temperature range, otherwise specifi cations are at T SYMBOL PARAMETER V Output Voltage Load Regulation LOADREG g Error Amplifi er Transconductance m1,2 I Input DC Supply Current Q Pulse-Skipping or Forced Continuous Mode (One Channel On) Pulse-Skipping ...
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LTC3788-1 ELECTRICAL CHARACTERISTICS junction temperature range, otherwise specifi cations are at T SYMBOL PARAMETER INTV Linear Regulator CC V Internal V Voltage INTVCCVIN CC V INTV Load Regulation LDOVIN CC V Internal V Voltage INTVCCEXT CC V INTV Load Regulation ...
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TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency and Power Loss vs Output Current 100 0.01 0.1 OUTPUT CURRENT (A) BURST EFFICIENCY PULSE-SKIPPING EFFICIENCY CCM EFFICIENCY Effi ciency vs Input Voltage 100 I ...
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LTC3788-1 TYPICAL PERFORMANCE CHARACTERISTICS Inductor Current at Light Load FORCED CONTINUOUS MODE Burst Mode OPERATION 5A/DIV PULSE-SKIPPING MODE V = 12V 5μs/DIV 24V OUT I = 200μA LOAD FIGURE 9 CIRCUIT Regulated Feedback Voltage vs Temperature 1.212 ...
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TYPICAL PERFORMANCE CHARACTERISTICS Quiescent Current vs Temperature 170 V = 12V 1.25V FB 160 RUN2 = GND 150 140 130 120 110 100 –45 – 105 TEMPERATURE (°C) 37881 G13 INTV Line Regulation ...
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LTC3788-1 TYPICAL PERFORMANCE CHARACTERISTICS SENSE Pin Input Current vs Temperature 260 V = 12V SENSE 240 220 + SENSE PIN 200 180 160 140 120 100 – SENSE PIN 0 – 105 ...
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PIN FUNCTIONS – – SENSE1 , SENSE2 (Pin 4, Pin 10): Negative Current Sense Comparator Input. The (–) input to the current comparator is normally connected to the negative terminal of a current sense resistor connected in series with the ...
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LTC3788-1 BLOCK DIAGRAM PGOOD1 + 1.32V – VFB1 + – 1.08V 20μA FREQ CLK2 VCO CLK1 PFD PLLIN/ MODE SYNC DET 100k VBIAS SHDN EXTV CC 5.4V 5.4V LDO LDO + – 3.8V + INTV SGND CC 4.8V ...
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OPERATION (Refer to Block Diagram) Main Control Loop The LTC3788-1 uses a constant-frequency, current mode step-up architecture with the two controller channels oper- ating 180 degrees out-of-phase. During normal operation, each external bottom MOSFET is turned on when the clock ...
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LTC3788-1 OPERATION In sleep mode, much of the internal circuitry is turned off, reducing the quiescent current that the LTC3788-1 draws. If one channel is shut down and the other channel is in sleep mode, the LTC3788-1 draws only 125μA ...
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OPERATION The typical capture range of the LTC3788-1’s PLL is from approximately 55kHz to 1MHz, and is guaranteed to lock to an external clock source whose frequency is be- tween 75kHz and 850kHz. The typical input clock thresholds on the ...
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LTC3788-1 APPLICATIONS INFORMATION The Typical Application on the fi rst page is a basic LTC3788-1 application circuit. LTC3788-1 can be confi gured to use either inductor DCR (DC resistance) sensing or a discrete sense resistor (R ) for current sensing. ...
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APPLICATIONS INFORMATION Sense Resistor Current Sensing A typical sensing circuit using a discrete resistor is shown in Figure 2a chosen based on the required SENSE output current. The current comparator has a maximum threshold V . The current ...
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LTC3788-1 APPLICATIONS INFORMATION Ensure that R1 has a power rating higher than this value. If high effi ciency is necessary at light loads, consider this power loss when deciding whether to use DCR sensing or sense resistors. Light load power ...
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APPLICATIONS INFORMATION to the gate charge curve specifi operating in continuous mode, the duty cycles for the top and bottom MOSFETs are given by: V OUT = Main Switch Duty Cycle Synchronous S S witch Duty Cycle The ...
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LTC3788-1 APPLICATIONS INFORMATION output capacitor depend on the duty cycle, the number of phases and the maximum output current. Figure 3 il- lustrates the normalized output capacitor ripple current as a function of duty cycle in a 2-phase confi guration. ...
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APPLICATIONS INFORMATION bypassing is needed to supply the high transient currents required by the MOSFET gate drivers and to prevent in- teraction between the channels. High input voltage applications in which large MOSFETs are being driven at high frequencies may ...
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LTC3788-1 APPLICATIONS INFORMATION Phase-Locked Loop and Frequency Synchronization The LTC3788-1 has an internal phase-locked loop (PLL) comprised of a phase frequency detector, a low pass fi lter and a voltage-controlled oscillator (VCO). This allows the turn-on of the top MOSFET ...
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APPLICATIONS INFORMATION Effi ciency Considerations The percent effi ciency of a switching regulator is equal to the output power divided by the input power times 100 often useful to analyze individual losses to determine what is limiting the ...
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LTC3788-1 APPLICATIONS INFORMATION a realistic load step condition. The initial output voltage step resulting from the step change in output current may not be within the bandwidth of the feedback loop, so this signal cannot be used to determine phase ...
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APPLICATIONS INFORMATION 2. Are the signal and power grounds kept separate? The combined IC signal ground pin and the ground return of C must return to the combined C INTVCC The path formed by the bottom N-channel MOSFET and the ...
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LTC3788-1 APPLICATIONS INFORMATION f IN Figure 7. Recommended Printed Circuit Layout Diagram 24 – SENSE1 + V SENSE1 PGOOD1 PULL-UP SS1 SW1 TG1 LTC3788 BOOST1 ITH1 BG1 VFB1 VBIAS PGND FREQ EXTV CC PLLIN/MODE INTV CC SGND RUN1 ...
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APPLICATIONS INFORMATION BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH SENSE1 C SW1 OUT1 L2 R SENSE2 C SW2 OUT2 Figure 8. Branch Current Waveforms LTC3788-1 V OUT1 ...
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LTC3788-1 APPLICATIONS INFORMATION high current output loading at lower input voltages, look for inductive coupling between C IN MOSFET components to the sensitive current and voltage sensing traces. In addition, investigate common ground path voltage pickup between these components and ...
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TYPICAL APPLICATIONS 26.1k 232k 0.1μ 0.1μF A1 12.1k 220pF ITH1 15nF ITH1 ITH1 8.87k 0.01μF SS1 INTV CC R FREQ ...
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LTC3788-1 PACKAGE DESCRIPTION .254 MIN .0165 ± .0015 RECOMMENDED SOLDER PAD LAYOUT .0075 – .0098 (0.19 – 0.25) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *DIMENSION ...
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... Updated Note on Typical Application Updated Related Parts Table Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC3788-1 ...
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... SENSE2 1.25μH 3mΩ MTOP2 V OUT2 12V, 10A + C C OUTA2 OUTB2 22μF 220μF 4 37881 TA02 ≤ 36V, IN Operation at Light Load. MSOP-10 ≤ 30V, SSOP-24, 5mm × 5mm QFN-32 OUT LT 0410 REV A • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2009 * * 37881fa ...