LTC3731HGTR Linear Technology, LTC3731HGTR Datasheet
LTC3731HGTR
Specifications of LTC3731HGTR
Related parts for LTC3731HGTR
LTC3731HGTR Summary of contents
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... Please refer to the LTC3731 data sheet for 0°C to 70°C and –40°C to 85°C rated versions. , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Burst Mode, OPTI-LOOP and PolyPhase are registered trademarks of Linear Technology Corporation ...
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LTC3731H ABSOLUTE AXI U RATI GS (Note 1) Topside Driver Voltages (BOOST ) ............ 38V to –0.3V N Switch Voltage (SW )................................... 32V to –5V N Boosted Driver Voltage (BOOST – Peak Output Current <1ms ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER I FCB Bias Current FCB V Burst Inhibit Threshold BINHIBIT UVR Undervoltage RUN/SS Reset UVADJ Undervoltage Lockout Threshold I Undervoltage Bias Current UVADJ I Input DC Supply Current Q ...
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LTC3731H ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER V PLLIN Input Threshold PLLTH R PLLIN Input Resistance PLLIN I Phase Detector Output Current PLLFLTR Sinking Capability Sourcing Capability R Controller 2-Controller 1 Phase RELPHS Controller 3-Controller ...
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W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs I (Figure 14) OUT 100 V = OPEN 90 FCB FCB FCB ...
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LTC3731H W U TYPICAL PERFOR A CE CHARACTERISTICS Short-Circuit Arming and Latchoff vs Temperature 5 ARMING 4 LATCHOFF –50 – 100 125 150 TEMPERATURE (°C) 3731H G10 Maximum SENSE ...
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W U TYPICAL PERFOR A CE CHARACTERISTICS Shed Mode at 1 Amp, Light Load Current (Circuit of Figure 14) V OUT AC, 20mV/DIV V SW1 10V/DIV V SW2 10V/DIV V SW3 10V/DIV V = 12V 4µs/DIV 1.5V ...
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LTC3731H CTIO S BG1 to BG3: High Current Gate Drives for Bottom N-Channel MOSFETs. Voltage swing at these pins is from ground to V BOOST1 to BOOST3: Positive Supply Pins to the Topside Floating Drivers. ...
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CTIO AL DIAGRA PLLIN PHASE DET F IN 50k PLLFLTR CLKOUT CLK1 CLK2 OSCILLATOR PHASMD CLK3 PGOOD – 0.66V + 100µs EAIN DELAY – PROTECTION + 0.54V FCB + FCB – 0.6V R1 ...
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LTC3731H U OPERATIO (Refer to Functional Diagram) Main Control Loop The IC uses a constant frequency, current mode step- down architecture. During normal operation, each top MOSFET is turned on each cycle when the oscillator sets the RS latch, and ...
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U OPERATIO (Refer to Functional Diagram) C) Continuous Current Operation Tying the FCB pin to ground will force continuous current operation. This is the least efficient operating mode, but may be desirable in certain applications. The output can source or ...
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LTC3731H U OPERATIO (Refer to Functional Diagram) Input Undervoltage Reset The RUN/SS capacitor will be reset if the input voltage ( allowed to fall below approximately 4V. The CC capacitor on the RUN/SS pin will be discharged until ...
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U U APPLICATIO S I FOR ATIO In a PolyPhase converter, the net ripple current seen by the output capacitor is much smaller than the individual inductor ripple currents due to the ripple cancellation. The details on how to calculate ...
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LTC3731H U U APPLICATIO S I FOR ATIO in applications that have an output voltage that is less than 1/3 of the input voltage. In applications where V the top MOSFETs’ “on” resistance is normally less impor- tant for overall ...
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U U APPLICATIO S I FOR ATIO 2 Both MOSFETs have I R losses while the topside N-channel equation includes an additional term for transition losses, which peak at the highest input voltage. For V high current efficiency generally improves ...
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LTC3731H U U APPLICATIO S I FOR ATIO power loss when compared to a single phase design. Battery/input protection fuse resistance (if used), PC board trace and connector resistance losses are also reduced by the reduction of the input ripple ...
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U U APPLICATIO S I FOR ATIO available in case heights ranging from 2mm to 4mm. Other capacitor types include Sanyo POS-CAP, Sanyo OS-CON, Nichicon PL series and Sprague 595D series. Consult the manufacturer for other specific recommendations. R Selection ...
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LTC3731H U U APPLICATIO S I FOR ATIO An internal 1.5µA current source charges up the C capacitor. When the voltage on RUN/SS reaches 1.5V, the controller is permitted to start operating. As the voltage on RUN/SS increases from 1.5V ...
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U U APPLICATIO S I FOR ATIO Current Foldback In certain applications, it may be desirable to defeat the internal current foldback function. A negative impedance is experienced when powering a switching regulator. That is, the input current is higher ...
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LTC3731H U U APPLICATIO S I FOR ATIO down the PLLFLTR pin. If the external and internal fre- quencies are the same, but exhibit a phase difference, the current sources turn on for an amount of time correspond- ing to ...
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U U APPLICATIO S I FOR ATIO Efficiency Considerations The percent efficiency 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 ...
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LTC3731H U U APPLICATIO S I FOR ATIO Automotive Considerations: Plugging into the Cigarette Lighter As battery-powered devices go mobile, there is a natural interest in plugging into the cigarette lighter in order to conserve or even recharge battery packs ...
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U U APPLICATIO S I FOR ATIO The power dissipation on the topside MOSFET can be estimated. Using a Fairchild FDS6688 for example 7mΩ 15nC/15V = 1000pF. At maximum input MILLER voltage with T(estimated) = 50°C: ...
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LTC3731H U U APPLICATIO S I FOR ATIO BOLD LINES INDICATE HIGH, SWITCHING CURRENTS. KEEP LINES TO A MINIMUM LENGTH. INDUCTOR LTC3731H + SENSE 1000pF – SENSE OUTPUT CAPACITOR Figure 12. Kelvin Sensing ...
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U U APPLICATIO S I FOR ATIO ground should return to the negative terminal of the input capacitor and not share a common ground path with any switched current paths. The left half of the circuit gives rise to the ...
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LTC3731H U U APPLICATIO S I FOR ATIO The worst-case input RMS ripple current for a single stage design peaks at twice the value of the output voltage. The worst-case input RMS ripple current for a two stage design results ...
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U U APPLICATIO S I FOR ATIO Total of all three main MOSFETs’ DC loss: 2 ⎛ ⎞ ⎛ ⎞ OUT 1 δ + MAX ⎝ ⎜ ⎠ ⎟ ⎝ ⎜ ⎠ ...
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LTC3731H U TYPICAL APPLICATIO S 1µF OPTIONAL FILTER FOR SYNCHRONIZATION 1000pF SYNC IN 0.01µF PLLIN 300kHz 10k 3 PLLFLTR 4 FCB 5 100pF NC 6 6.04k 9.09k 300pF 8 EAIN 9 ...
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U TYPICAL APPLICATIO S SYNC IN 1k 68pF 8.2k 3.3k 4.7k 15k 220pF 330pF EAIN 10Ω× 1000pF – 1000pF – S2 – S3 1000pF + 0.1µF S3 RUN/SS 357k V IN 121k ...
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LTC3731H U TYPICAL APPLICATIO S 3-Phase Boost Converter OUT IN C18 C19 R2 LT3010 1µF 1µ 50V 10V SHDN ADJ R5 GND 249k OPT 0Ω ...
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... FLASH SHALL NOT EXCEED .254mm (.010") PER SIDE 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. ...
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... Intel Pentium M (Centrino™) CPU, DC/DC Synchronous Step-Down Controller LTC3778 Optional R Current Mode Synchronous Step-Down SENSE Controller LTC3832 Low V High Power Synchronous Controller trademark of Linear Technology Corporation. SENSE Linear Technology Corporation 32 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● COMMENTS Reduces C IN 3.5V ≤ V ≤ ...