LTC3868IUH#TRPBF Linear Technology, LTC3868IUH#TRPBF Datasheet
LTC3868IUH#TRPBF
Specifications of LTC3868IUH#TRPBF
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LTC3868IUH#TRPBF Summary of contents
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... PGOOD output, without phase modulation or a clock output, see the LTC3868-1 data sheet. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP , PolyPhase, μModule, Linear Technology and the Linear logo are registered trademarks and No R Corporation. All other trademarks are the property of their respective owners. Protected by U.S. ...
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... LTC3868EUH#PBF LTC3868EUH#TRPBF LTC3868IUH#PBF LTC3868IUH#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container.Consult LTC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: For more information on tape and reel specifi ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER V Output Voltage Load Regulation LOADREG g Transconductance Amplifi m1,2 I Input DC Supply Current Q Pulse-Skipping or Forced Continuous Mode (One Channel On) Pulse-Skipping or ...
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LTC3868 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER TG/BG t Top Gate Off to Bottom Gate On Delay 1D Synchronous Switch-On Delay Time BG/TG t Bottom Gate Off to Top Gate On Delay 1D Top ...
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TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency and Power Loss vs Output Current 100 FIGURE 12 CIRCUIT 12V 3.3V OUT 0.0001 0.001 0.01 OUTPUT CURRENT (A) Effi ...
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LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS Total Input Supply Current vs Input Voltage 400 FIGURE 12 CIRCUIT V = 3.3V 350 OUT ONE CHANNEL ON 300 300μA LOAD 250 200 NO LOAD 150 100 INPUT ...
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TYPICAL PERFORMANCE CHARACTERISTICS Soft-Start Pull-Up Current vs Temperature 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 – 105 –45 30 TEMPERATURE (°C) 3868 G19 – SENSE Pin Input Current vs Temperature 3.3V ...
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LTC3868 TYPICAL PERFORMANCE CHARACTERISTICS INTV and EXTV CC 5. 12V IN 5.15 5.10 5.05 EXTV 5.00 4. 100 120 140 LOAD CURRENT (mA) PIN FUNCTIONS – – SENSE1 , SENSE2 ...
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PIN FUNCTIONS RUN1, RUN2 (Pin 7, Pin 8): Digital Run Control Inputs for Each Controller. Forcing either of these pins below 1.26V shuts down that controller. Forcing both of these pins below 0.7V shuts down the entire LTC3868, reducing quiescent ...
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LTC3868 FUNCTIONAL DIAGRAM PHASMD PGOOD1 + 0.88V 27 3 – V FB1 + – 0.72V PGOOD2 + 0.88V 14 – V FB2 + – 0.72V 20μA FREQ 2 VCO C LP SYNC DET PLLIN/MODE 5 100k I LIM CURRENT 28 ...
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OPERATION (Refer to the Functional Diagram) The LTC3868 uses a constant frequency, current mode step-down architecture with the two controller channels operating 180 degrees out of phase. During normal op- eration, each external top MOSFET is turned on when the ...
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LTC3868 OPERATION (Refer to the Functional Diagram) INTV CC SS VOLTAGE 2V 0.8V LATCHOFF COMMAND 0V SS PIN 1μA CURRENT –9μA OUTPUT VOLTAGE LATCHOFF ARMING ENABLE SOFT-START INTERVAL Figure 1. Latchoff Timing Diagram The delay time from when a short-circuit ...
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OPERATION (Refer to the Functional Diagram) When a controller is enabled for Burst Mode operation, the inductor current is not allowed to reverse. The reverse current comparator, IR, turns off the bottom external MOSFET just before the inductor current reaches ...
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LTC3868 OPERATION (Refer to the Functional Diagram) between the two internal controllers, as summarized in Table 1. The phases are calculated relative to the zero degrees phase being defi ned as the rising edge of the top gate driver output ...
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OPERATION (Refer to the Functional Diagram) meaning that the actual power wasted is reduced by a fac- tor of 2.66. The reduced input ripple voltage also means less power is lost in the input power path, which could include batteries, ...
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LTC3868 APPLICATIONS INFORMATION The Typical Application on the fi rst page is a basic LTC3868 application circuit. LTC3868 can be confi gured to use either DCR (inductor resistance) sensing or low value resistor sensing. The choice between the two current ...
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APPLICATIONS INFORMATION duty factor. A curve is provided in the Typical Performance Characteristics section to estimate this reduction in peak output current depending upon the operating duty factor. Inductor DCR Sensing For applications requiring the highest possible effi ciency at ...
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LTC3868 APPLICATIONS INFORMATION The equivalent resistance R1||R2 is scaled to the room temperature inductance and maximum DCR DCR at 20°C • C1 The sense resistor values are: R1|| R2 R1• ...
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APPLICATIONS INFORMATION Pin Connection). Consequently, logic-level threshold MOSFETs must be used in most applications. The only exception is if low input voltage is expected (V then, sub-logic level threshold MOSFETs (V should be used. Pay close attention to the BV ...
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LTC3868 APPLICATIONS INFORMATION large voltage transients, a low ESR capacitor sized for the maximum RMS current of one channel must be used. The maximum RMS capacitor current is given by ⎡ ≈ MAX C Required I V ⎣ ...
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APPLICATIONS INFORMATION Soft-start is enabled by simply connecting a capacitor from the SS pin to ground, as shown in Figure 7. An internal 1μA current source charges the capacitor, providing a linear ramping voltage at the SS pin. The LTC3868 ...
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LTC3868 APPLICATIONS INFORMATION The following list summarizes the four possible connec- tions for EXTV : CC 1. EXTV Left Open (or Grounded). This will cause INTV powered from the internal 5.1V regulator result- ing in an effi ...
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APPLICATIONS INFORMATION A comparator monitors the output for overvoltage condi- tions. The comparator detects faults greater than 10% above the nominal output voltage. When this condition is sensed, the top MOSFET is turned off and the bottom MOSFET is turned ...
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LTC3868 APPLICATIONS INFORMATION Minimum On-Time Considerations Minimum on-time the smallest time duration ON(MIN) that the LTC3868 is capable of turning on the top MOSFET determined by internal timing delays and the gate charge required to ...
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APPLICATIONS INFORMATION 4. Transition losses apply only to the topside MOSFET(s), and become signifi cant only when operating at high input voltages (typically 15V or greater). Transition losses can be estimated from: Transition Loss = (1.7) • V • 2 ...
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LTC3868 APPLICATIONS INFORMATION greater than 1:50, the switch rise time LOAD OUT should be controlled so that the load rise time is limited to approximately 25 • Thus a 10μF capacitor would LOAD require ...
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APPLICATIONS INFORMATION PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the IC. These items are also illustrated graphically in the layout diagram of Figure 10. Figure ...
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LTC3868 APPLICATIONS INFORMATION I TH1 V FB1 SENSE1 SENSE1 FREQ PHASMD CLKOUT f IN PLLIN/MODE RUN1 RUN2 SGND SENSE2 SENSE2 V FB2 I TH2 SS2 Figure 10. Recommended Printed Circuit Layout Diagram 28 R SS1 PU2 V PULL-UP LTC3868 (<6V) ...
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APPLICATIONS INFORMATION BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH. SW1 L1 R SENSE1 D1 C OUT1 SW2 L2 R SENSE2 D2 C OUT2 Figure 11. Branch Current Waveforms LTC3868 ...
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LTC3868 APPLICATIONS INFORMATION Reduce V from its nominal level to verify operation IN of the regulator in dropout. Check the operation of the undervoltage lockout circuit by further lowering V monitoring the outputs to verify operation. Investigate whether any problems ...
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TYPICAL APPLICATIONS R B1 215k C F1 15pF C1 1nF R A1 68.1k C 150pF ITH1A R 15k ITH1 C 820pF ITH1 C 0.1μF SS1 C 0.1μF SS2 C 680pF ITH2 R 27k ITH2 C 100pF ITH2A R A2 44.2k ...
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LTC3868 TYPICAL APPLICATIONS R B1 143k 22pF 1nF R A1 68.1k C 100pF ITH1A R 22k ITH1 C 820pF ITH1 C 0.01μF SS1 C 0.01μF SS2 C 820pF ITH2 R 15k ITH2 C 150pF ITH2A R A2 ...
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TYPICAL APPLICATIONS R B1 475k C F1 33pF C1 1nF R A1 34k C 100pF ITH1A R 10k ITH1 C 0.01μF C 680pF SS1 ITH1 R FREQ 60k C 0.01μF SS2 C 680pF ITH2 R 17k ITH2 C 100pF ITH2A ...
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LTC3868 TYPICAL APPLICATIONS R B1 28. 56pF 1nF R A1 115k C 200pF ITH1A R 3.93k ITH1 C 1000pF ITH1 C 0.01μF SS1 R FREQ 60k C 0.01μF SS2 C 1000pF ITH2 R 3.93k ITH2 C 200pF ...
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TYPICAL APPLICATIONS High Effi ciency Dual 1V/1.2V Step-Down Converter with Inductor DCR Current Sensing R B1 28. 56pF C1 0.1μ 115k C 200pF ITH1A R 3.93k ITH1 C 1000pF ITH1 C 0.01μF SS1 R FREQ 65k ...
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LTC3868 PACKAGE DESCRIPTION 5.50 0.05 4.10 0.05 3.45 0.05 3.50 REF (4 SIDES) 3.45 0.05 RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 0.10 (4 SIDES) PIN 1 TOP MARK (NOTE 6) NOTE: 1. ...
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... Changes to Functional Diagram Changes to Typical Applications 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. LTC3868 ...
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... I = 170μA OUT Q ≤ 24V 50μA OUT Q ≤ 10V 30μA OUT Q ≤ 10V 80μA OUT Q = 120μA, TSSOP- 40μA, MSOP-10E Q LT 1210 REV D • PRINTED IN USA © LINEAR TECHNOLOGY CORPORA TION 2009 ≤ 38V, IN ≤ 60V, IN ≤ 60V, IN 3868fd ...