LTC3735EUHF Linear Technology, LTC3735EUHF Datasheet

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... OPTI-LOOP response to be optimized for a wide range of output capaci- tance and ESR values. , LTC and LT are registered trademarks of Linear Technology Corporation. OPTI-LOOP is a registered trademark of Linear Technology Corporation. MCH_PG TG1 M1 1μ ...

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... SENSE1 9 + SENSE2 10 – SENSE2 11 RDPRSLP 38-LEAD (7mm × 5mm) PLASTIC QFN = 125°C, θ T JMAX EXPOSED PAD (PIN 39) IS SIGNAL GROUND MUST BE CONNECTED TO PCB AND SGND ORDER PART TOP VIEW NUMBER LTC3735EUHF BOOST2 29 TG2 28 SW2 BG1 39 25 PGND 24 BG2 23 VID5 ...

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

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... Note calculated from the ambient temperature T J dissipation P according to the following formula: D LTC3735EG • 85°C/ LTC3735EUHF • 34°C/ The ● denotes the specifications which apply over the full operating = 25° 5V unless otherwise noted. A ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS Active Mode Efficiency (Figure 14) 100 V = 1.468V ID PSI = 7. 20V LOAD ...

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LTC3735 W U TYPICAL PERFOR A CE CHARACTERISTICS Load Regulation (Without AVP) 0.0 –0.1 –0.2 –0.3 –0 LOAD CURRENT (A) Maximum Current Sense Threshold vs Temperature –50 – ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS V Shutdown Latch RUN/SS Thresholds vs Temperature 4.5 LATCH ARMING 4.0 3.5 3.0 LATCHOFF THRESHOLD 2.5 2.0 1.5 1.0 0.5 0 –50 – 100 125 TEMPERATURE (°C) 3735 G21 ...

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LTC3735 CTIO S G Package/UHF Package RUN/SS (Pin 16/Pin 15): 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 ...

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CTIO AL DIAGRA R3 MCH_PG FREQSET CLK1 OSCILLATOR CLK2 TO SECOND CHANNEL DPRSLPVR STP_CPUB VID CHANGE PGOOD – 110μs BLANKING + RUN – – – OAOUT 3V ...

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LTC3735 U OPERATIO (Refer to Functional Diagram) Main Control Loop The LTC3735 uses a constant frequency, current mode step-down architecture with the two output stages oper- ating 180 degrees out of phase. During normal operation, each top MOSFET is turned ...

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U OPERATIO (Refer to Functional Diagram) Output Voltage at Start-Up and at Deeper Sleep State Under normal conditions, the output voltage of the regu- lator is commanded by six VID bits, except at start-up and at deeper sleep state. At ...

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... The PolyPhase approach reduces both input and output ripple currents while optimizing individual output stages to run at a lower fundamental frequency, enhancing efficiency. PolyPhase is a registered trademark of Linear Technology Corporation. 600 550 500 450 ...

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... The details on how to calculate the net output ripple current can be found in Linear Technology Application Note 77. Figure 3 shows the net ripple current seen by the output capacitors for 1- and 2-phase configurations. The output ripple current is plotted for a fixed output voltage as the duty factor is varied between 10% and 90% on the x-axis ...

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LTC3735 U U APPLICATIO S I FOR ATIO Selection criteria for the power MOSFETs include the “ON” resistance R , gate charge Q DS(ON) G pacitance C , breakdown voltage BV RSS continuous drain current I . D(MAX) When the ...

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... W U RMS current must be used. The details of a closed form equation can be found in Linear Technology Application Note 77. Figure 4 shows the input capacitor ripple current for a 2-phase configuration with the output voltage fixed and input voltage varied. The input ripple current is nor- malized against the DC output current ...

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... RIPPLE of each stage. A closed form equation can be found in Linear Technology Application Note 77. Assuming induc- tors are selected to have same ripple percentage for both 1-phase and 2-phase configurations, Figure 5 shows the reduction of output ripple current by 2-phase operation. ...

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U U APPLICATIO S I FOR ATIO In surface mount applications, multiple capacitors may have to be paralleled to meet the ESR or RMS current handling requirements of the application. Aluminum elec- trolytic and dry tantalum capacitors are both available ...

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LTC3735 U U APPLICATIO S I FOR ATIO Table 2. VID Output Voltage Programming VID5 VID4 VID3 VID2 VID1 ...

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U U APPLICATIO S I FOR ATIO An internal 1.5μA current source charges up the soft-start capacitor When the voltage on RUN/SS reaches SS 1.5V, the controller is permitted to start operating. As the voltage on RUN/SS increases ...

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LTC3735 U U APPLICATIO S I FOR ATIO Output Voltage Set in Deep Sleep and Deeper Sleep States (Refer to the Functional Diagram) The output voltage can be offset by the STP_CPUB signal. When STP_CPUB becomes low, the output voltage ...

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U U APPLICATIO S I FOR ATIO current. After the controller has been started and been given adequate time to charge up the output capacitors and provide full load current, the RUN/SS capacitor is used for a short-circuit timer. If ...

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LTC3735 U U APPLICATIO S I FOR ATIO Active Voltage Positioning Active voltage positioning can be used to minimize peak- to-peak output voltage excursion under worst-case tran- sient loading conditions. The open-loop DC gain of the control loop is reduced ...

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U U APPLICATIO S I FOR ATIO topside MOSFET and the synchronous MOSFET. If the two MOSFETs have approximately the same R resistance of one MOSFET can simply be summed with the resistances and ESR to obtain ...

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LTC3735 U U APPLICATIO S I FOR ATIO the loop gain and phase. An output current pulse of 20% to 80% of full-load current having a rise time of <1μs will produce output voltage and I pin waveforms that will ...

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U U APPLICATIO S I FOR ATIO Tie the FREQSET pin to 1.2V, resistively divided down from PV to have 350kHz operation for each phase. CC The minimum on-time also occurs at maximum input voltage ...

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LTC3735 U U APPLICATIO S I FOR ATIO PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the LTC3735. Check the following in your layout: 1) Are ...

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U U APPLICATIO S I FOR ATIO BOLD LINES INDICATE HIGH, SWITCHING CURRENT LINES. KEEP LINES TO A MINIMUM LENGTH. Figure 12. Instantaneous Current Path Flow in a Multiple Phase Switching Regulator Simplified ...

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... When the RMS current is calculated, higher effective duty factor results and the peak current levels are divided as long as the currents in each stage are balanced. Refer to Linear Technology Application Note 19 for a detailed description of how to calculate RMS current for the single stage switching regulator. Figures 3 and 4 illustrate how the input and output currents are reduced by using an additional phase ...

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U TYPICAL APPLICATIO Figure 14 shows a typical application using the LTC3735 to power the mobile CPU core. The input can vary from 5V to 24V; the output voltage can be programmed from 0.7V to 1.708V with a maximum current ...

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LTC3735 PACKAGE DESCRIPTIO 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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... DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U UHF Package 38-Lead Plastic QFN (5mm × ...

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... Power Good Indication LTC3732 3-Phase High Efficiency High Current Controller LTC3734 Single Phase DC/DC Controller for Intel IMVP-4 Compatible Processors Adaptive Power and No R are a trademarks of Linear Technology Corporation. SENSE Linear Technology Corporation 32 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...