LTC3729EG Linear Technology, LTC3729EG Datasheet

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... Desktop Computers/Servers n Large Memory Arrays n DC Power Distribution Systems n L, LT, LTC, LTM, PolyPhase, OPTI‑LOOP , Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 0.1µF LTC3729 ...

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... JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC3729EG#PBF LTC3729EG#TRPBF LTC3729EUH#PBF LTC3729EUH#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non‑standard lead based finish parts. For more information on lead free part marking, go to: ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER Main Control Loop V Regulated Feedback Voltage EAIN V Maximum Current Sense Threshold SENSEMAX I Feedback Current INEAIN V Output Voltage Load Regulation LOADREG V Reference Voltage Line Regulation ...

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... CMRR Common Mode Rejection Ratio DA R Input Resistance IN Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note calculated from the ambient temperature T J dissipation P according to the following formulas: D LTC3729EG • 95°C/ LTC3729EUH • 34°C/ ...

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TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Output Current (Figure 12) 100 12V 20V 3.3V OUT EXTVCC I = ...

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LTC3729 TYPICAL PERFORMANCE CHARACTERISTICS Maximum Current Sense Threshold vs V (Soft-Start) RUN/ 1.6V SENSE(CM (V) RUN/SS 3729 Load Regulation 0.0 FCB = 15V ...

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TYPICAL PERFORMANCE CHARACTERISTICS Soft-Start Up (Figure 12) V ITH 1V/DIV V OUT 2V/DIV V RUNSS 2V/DIV 100ms/DIV Current Sense Pin Input Current vs Temperature OUT –50 – ...

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LTC3729 PIN FUNCTIONS G Package/UH Package RUN/SS (Pin 1/Pin 28): Combination of Soft‑Start, Run Control Input and Short‑Circuit Detection Timer. A capaci‑ tor to ground at this pin sets the ramp time to full current output. Forcing this pin below ...

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PIN FUNCTIONS G Package/UH Package EXTV (Pin 22/Pin 21): External Power Input Internal Switch . This switch closes and supplies INTV bypassing the internal low dropout regulator whenever EXTV is higher than 4.7V. See EXTV CC the ...

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LTC3729 OPERATION (Refer to Functional Diagram) Main Control Loop The LTC3729 uses a constant frequency, current mode step‑down architecture. During normal operation, the top MOSFET is turned on each cycle when the oscillator sets the RS latch, and turned off ...

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OPERATION (Refer to Functional Diagram) INTV /EXTV Power CC CC Power for the top and bottom MOSFET drivers and most of the IC circuitry is derived from INTV pin is left open, an internal 5V low dropout regulator supplies INTV ...

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LTC3729 APPLICATIONS INFORMATION When using the controller in very low dropout conditions, the maximum output current level will be reduced due to internal slope compensation required to meet stability criterion for buck regulators operating at greater than 50% duty factor. ...

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APPLICATIONS INFORMATION 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0.1 0.2 0.3 0.4 0.5 DUTY FACTOR (V Figure 3. Normalized Peak Output Current vs Duty Factor [I ≈ 0.3 (∆I )] RMS O(P–P) Accepting larger values ...

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LTC3729 APPLICATIONS INFORMATION 2 V  I  OUT MAX     MAIN   MAX  ...

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APPLICATIONS INFORMATION This makes it advisable to further derate the capacitor choose a capacitor rated at a higher temperature than required. Several capacitors may also be paralleled to meet size or height requirements in the design. Always consult ...

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LTC3729 APPLICATIONS INFORMATION maximum junction temperature rating for the LTC3729 to be exceeded. The supply current is dominated by the gate charge supply current, in addition to the current drawn from the differential amplifier output. The gate charge is dependent ...

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APPLICATIONS INFORMATION OPTIONAL EXTV CONNECTION < V < SEC LTC3729 V IN 1N4148 TG1 6.8V EXTV CC N-CH SW1 T1 BG1 N-CH PGND Figure 5a. Secondary Output Loop and EXTV gate‑source of ...

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LTC3729 APPLICATIONS INFORMATION pulled all the way to ground there is a delay before starting of approximately: 1. 1.25s / µF DELAY SS 1.2µA The time for the output current to ramp up is then: ...

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APPLICATIONS INFORMATION 400kHz. The nominal operating frequency range of the LTC3729 is 250kHz to 550kHz. The phase detector used is an edge sensitive digital type which provides zero degrees phase shift between the ex‑ ternal and internal oscillators. This type ...

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LTC3729 APPLICATIONS INFORMATION Voltage Positioning Voltage positioning can be used to minimize peak‑to‑peak output voltage excursions under worst‑case transient loading conditions. The open‑loop DC gain of the control loop is reduced depending upon the maximum load step specifications. Voltage positioning ...

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APPLICATIONS INFORMATION of increasingly lower output voltages and higher currents required by high performance digital systems is not doubling but quadrupling the importance of loss terms in the switching regulator system! 4) Transition losses apply only to the topside MOSFET(s), ...

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LTC3729 APPLICATIONS INFORMATION Design Example (Using Two Phases design example, assume (nominal (max 1.8V 20A 70°C and f = 300kHz. OUT MAX A The inductance value is ...

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APPLICATIONS INFORMATION which is much less than normal, full‑load conditions. Incidentally, since the load no longer dissipates power in the shorted condition, total system power dissipation is decreased by over 99%. The duty cycles when the peak RMS input current ...

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LTC3729 APPLICATIONS INFORMATION The diagram in Figure 9 illustrates all branch currents in a 2‑phase switching regulator. It becomes very clear after studying the current waveforms why it is critical to keep the high‑switching‑current paths to a small physical size. ...

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APPLICATIONS INFORMATION Simplified Visual Explanation of How a 2-Phase Controller Reduces Both Input and Output RMS Ripple Current A multiphase power supply significantly reduces the amount of ripple current in both the input and output capacitors. The RMS input ripple ...

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LTC3729 TYPICAL APPLICATIONS OPTIONAL SYNC CLOCK IN 1 1000pF 2 0.33µF 3 8.06k 0.3µF 7 6800pF 8 47k 100pF 9 25.5k 470pF 13 14 1000pF 24k 75k 1 1000pF ...

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PACKAGE DESCRIPTION 7.8 – 8.2 0.42 ±0.03 RECOMMENDED SOLDER PAD LAYOUT 5.00 – 5.60** (.197 – .221) 0.09 – 0.25 0.55 – 0.95 (.0035 – .010) (.022 – .037) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) ...

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LTC3729 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 ...

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... Updated Figure 11, Figure 12 Updated Related Parts 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. LTC3729 ...

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... IN ≤ 5.25V OUT ≤ 38V, IN ≤ 12V OUT ≤ 24V, IN ≤ 24V 20ns IN ON(MIN) ≤ 38V, 0.8V ≤ V ≤ 24V 50µA OUT Q 0311 REV B • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 2001 16V V OUT 3.3V/30A 3729TA02 Up to 24V, 3729fb ...