LTC3728EUH#PBF Linear Technology, LTC3728EUH#PBF Datasheet
LTC3728EUH#PBF
Specifications of LTC3728EUH#PBF
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LTC3728EUH#PBF Summary of contents
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... L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5929620, 6177787, 6144194, 6100678, 5408150, 6580258, 5705919 ...
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... T = 90°C/W - SINGLE LAYER BOARD JMAX JA 68º C LAYER ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC3728EG#PBF LTC3728EG#TRPBF LTC3728IG#PBF LTC3728IG#TRPBF LTC3728EUH#PBF LTC3728EUH#TRPBF LTC3728IUH#PBF LTC3728IUH#TRPBF LEAD BASED FINISH TAPE AND REEL LTC3728EG LTC3728EG#TR LTC3728IG LTC3728IG#TR LTC3728EUH LTC3728EUH#TR LTC3728IUH LTC3728IUH#TR Consult LTC Marketing for parts specifi ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER Main Control Loops V Regulated Feedback Voltage OSENSE1 Feedback Current OSENSE1 Reference Voltage Line Regulation REFLNREG V Output Voltage Load Regulation LOADREG g Transconductance ...
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LTC3728 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER V EXTV Switchover Voltage EXTVCC CC V EXTV Hysteresis LDOHYS CC Oscillator and Phase-Locked Loop f Nominal Frequency NOM f Lowest Frequency LOW f Highest Frequency HIGH ...
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TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Output Current and Mode (Figure 13) 100 Burst Mode 90 OPERATION 80 70 FORCED 60 CONTINUOUS MODE (PWM CONSTANT FREQUENCY 30 (BURST DISABLE 15V ...
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LTC3728 TYPICAL PERFORMANCE CHARACTERISTICS Maximum Current Sense Threshold vs V (Soft-Start) RUN/ 1.6V SENSE(CM (V) RUN/SS 3728 G10 Load Regulation 0.0 FCB = ...
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TYPICAL PERFORMANCE CHARACTERISTICS Soft-Start Up (Figure 13) V OUT 5V/DIV V RUN/SS 5V/DIV I L 2A/DIV 3728 G19 5ms/DIV V = 15V OUT Input Source/Capacitor Instantaneous Current (Figure 13 2A/DIV V IN 200mV/DIV V ...
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LTC3728 TYPICAL PERFORMANCE CHARACTERISTICS Undervoltage Lockout vs Temperature 3.50 3.45 3.40 3.35 3.30 3.25 3.20 50 –50 – TEMPERATURE (°C) PIN FUNCTIONS G Package/UH Package RUN/SS1, RUN/SS2 (Pins 1, 15/Pins 28, 13): Combination of soft-start, run control inputs ...
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PIN FUNCTIONS INTV (Pin 21/Pin 20): Output of the Internal 5V Linear CC Low Dropout Regulator and the EXTV and control circuits are powered from this voltage source. Must be decoupled to power ground with a minimum of 4.7μF tantalum ...
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LTC3728 FUNCTIONAL DIAGRAM PLLIN F PHASE DET IN 50k PLLFLTR CLK1 R LP OSCILLATOR CLK2 C LP – 0.86V + V OSENSE1 PGOOD – + 0.74V 0.86V – OSENSE2 – + 0.74V V SEC 1.5V – 4.5V 0.18μA ...
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OPERATION (Refer to Functional Diagram) Main Control Loop The LTC3728 uses a constant-frequency, current mode step-down architecture with the two controller channels operating 180 degrees out of phase. During normal opera- tion, each top MOSFET is turned on when the ...
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LTC3728 OPERATION (Refer to Functional Diagram) Continuous Current (PWM) Operation Tying the FCB pin to ground will force continuous current operation. This is the least effi cient operating mode, but may be desirable in certain applications. The output can source ...
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OPERATION (Refer to Functional Diagram 2.53A IN(MEAS) (a) Figure 3. Input Waveforms Comparing Single-Phase (a) and 2-Phase (b) Operation for Dual Switching Regulators Converting 12V to 5V and 3. Each. The Reduced Input Ripple with the ...
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LTC3728 OPERATION (Refer to Functional Diagram) A fi nal question: If 2-phase operation offers such an ad- vantage over single-phase operation for dual switching regulators, why hasn’t it been done before? The answer is that, while simple in concept, it ...
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APPLICATIONS INFORMATION Figure 1 on the fi rst page is a basic LTC3728 application circuit. External component selection is driven by the load requirement, and begins with the selection of R and the inductor value. Next, the power MOSFETs and ...
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LTC3728 APPLICATIONS INFORMATION load transient response and suffi cient ripple current sig- nal in the current loop. The maximum ΔI maximum input voltage. The inductor value also has secondary effects. The tran- sition to Burst Mode operation begins when the ...
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APPLICATIONS INFORMATION which are highest at high input voltages. For V the high current effi ciency generally improves with larger MOSFETs, while for V > 20V the transition losses rapidly IN increase to the point that the use of a ...
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LTC3728 APPLICATIONS INFORMATION the maximum RMS current of one channel must be used. The maximum RMS capacitor current is given by: V OUT C Required RMS MAX This formula has a maximum ...
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APPLICATIONS INFORMATION have lower storage capacity per unit volume than other capacitor types. These capacitors offer a very cost-effec- tive output capacitor solution and are an ideal choice when combined with a controller having high loop bandwidth. Tantalum capacitors offer ...
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LTC3728 APPLICATIONS INFORMATION factor of (Duty Cycle)/(Effi ciency). For 5V regulators this supply means connecting the EXTV However, for 3.3V and other lower voltage regulators, additional circuitry is required to derive INTV from the output. The following list summarizes the ...
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APPLICATIONS INFORMATION reference by the error amplifi er. The output voltage is given by the equation 0. OUT R1 where R1 and R2 are defi ned in Figure 2. + – SENSE /SENSE PINS The common ...
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LTC3728 APPLICATIONS INFORMATION Fault Conditions: Overcurrent Latchoff The RUN/SS pins also provide the ability to latch off the controller(s) when an overcurrent condition is detected. The RUN/SS capacitor used initially to turn on and limit SS the ...
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APPLICATIONS INFORMATION Fault Conditions: Overvoltage Protection (Crowbar) The overvoltage crowbar is designed to blow a system input fuse when the output voltage of the regulator rises much higher than nominal levels. The crowbar causes huge currents to fl ow that ...
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LTC3728 APPLICATIONS INFORMATION Minimum On-Time Considerations Minimum on-time the smallest time duration ON(MIN) that the LTC3728 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 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 specifi cations. Voltage positioning ...
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LTC3728 APPLICATIONS INFORMATION R = 10mΩ and R = 40mΩ (sum of both input SENSE ESR and output capacitance losses), then the total resistance is 130mΩ. This results in losses ranging from 3% to 13% as the output current increases ...
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APPLICATIONS INFORMATION loop. The output voltage settling behavior is related to the stability of the closed-loop system and will demonstrate the actual overall supply performance. A second, more severe transient is caused by switching in loads with large (>1μF) supply ...
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LTC3728 APPLICATIONS INFORMATION Design Example As a design example for one channel, assume V (nominal 22V(max 1.8V OUT f = 300kHz. The inductance value is chosen fi rst based on a 30% ripple current ...
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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 LTC3728. These items are also illustrated graphically in the layout diagram of Figure 10. Figure ...
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LTC3728 APPLICATIONS INFORMATION BOLD LINES INDICATE HIGH, SWITCHING CURRENT LINES. KEEP LINES TO A MINIMUM LENGTH. signal ground. The R2 and R4 connections should not be along the high current input feeds from ...
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APPLICATIONS INFORMATION PC Board Layout Debugging Start with one controller time helpful to use a DC-50MHz current probe to monitor the current in the inductor while testing the circuit. Monitor the output switching node (SW ...
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LTC3728 TYPICAL APPLICATIONS 59k 1 RUN/SS1 0 SENSE1 180pF 1000pF 3 – SENSE1 105k, 1% 20k OSENSE1 5 PLLFLTR 6 PLLIN 33pF 7 FCB LTC3728 8 I TH1 15k 1000pF 9 SGND 33pF 10 ...
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TYPICAL APPLICATIONS 1 RUN/SS1 0 SENSE1 27pF 1000pF 105k 3 SENSE1 1% 20k OSENSE1 5 0.01 F PLLFLTR 10k 1000pF 6 f PLLIN SYNC 33pF 7 FCB 8 I TH1 15k 220pF 9 SGND 33pF ...
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LTC3728 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 ...
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... ON THE TOP AND BOTTOM OF PACKAGE 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. UH32 Package 32-Lead Plastic QFN (5mm × ...
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... LTC1929/LTC1929-PG 2-Phase Synchronous Controllers LTC3711 No R Current Mode Synchronous Step-Down SENSE Controller with Digital 5-Bit Interface LTC3729 20A to 200A, 550kHz PolyPhase Synchronous Controller PolyPhase is a registered trademark of Linear Technology Corporation Linear Technology Corporation 36 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...