LTC1703CG#TRPBF Linear Technology, LTC1703CG#TRPBF Datasheet

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... Microprocessor Core and I/O Supplies ■ Multiple Logic Supply Generator ■ High Efficiency Power Conversion , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. U TYPICAL APPLICATIO ...

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LTC1703 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage V CC ........................................................................................... BOOST n ............................................................... 15V BOOST n – .................................................... 7V Input Voltage SW n .......................................................... – VID n ....................................................... – ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are 25°C. V SYMBOL PARAMETER Switching Characteristics V Oscillator Amplitude OSC f Oscillator Frequency OSC Φ Controller 2 Oscillator Phase OSC2 DC Minimum Duty Cycle MIN1 DC Minimum Duty Cycle MIN2 ...

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LTC1703 W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs Load Current 100 3.3V OUT V = 2.5V OUT 1.6V OUT LOAD CURRENT (A) 1703 ...

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CTIO S PV (Pin 1): Driver Power Supply Input power to the two BG n output drivers. PV connected to a voltage high enough to fully turn on the external MOSFETs QB1 and ...

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LTC1703 CTIO S VID n pin includes an on-chip 40kΩ pull-up resistor in series with a diode (see Block Diagram). V (Pin 18): Power Supply Input. All internal circuits CC except the output drivers are ...

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W BLOCK DIAGRA V CC 90% DUTY CYCLE OSC 550kHz 4µA SOFT RUN/SS1,2 START COMP1,2 I LIM 10µ MAX1,2 800mV SHUTDOWN TO THIS CONTROLLER 500mV CONTROLLER U U APPLICATIO S I FOR ATIO OVERVIEW The LTC1703 is ...

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LTC1703 U U APPLICATIO S I FOR ATIO Table 1. VID Inputs and Corresponding Output Voltage for Channel 1 CODE VID4 VID3 VID2 VID1 00000 GND GND GND GND 00001 GND GND GND GND 00010 GND GND GND Float 00011 ...

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U U APPLICATIO S I FOR ATIO converter, even in cases where the 1-step converter has higher total efficiency than the 2-step system typical microprocessor core supply regulator, for example, the regulator is usually located right next to ...

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LTC1703 U U APPLICATIO S I FOR ATIO of the equation—with a typical value on the order of 1µH, the inductor allows very fast di/dt slew rates. The result is superior transient response compared with conventional solutions. High Efficiency The ...

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U U APPLICATIO S I FOR ATIO This constant frequency operation brings with it a couple of benefits. Inductor and capacitor values can be chosen with a precise operating frequency in mind and the feed- back loop components can be ...

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LTC1703 U U APPLICATIO S I FOR ATIO current limits or QB dies trying to save the load. This behavior provides maximum protection against overvolt- age faults at the output, while allowing the circuit to re- sume normal operation when ...

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U U APPLICATIO S I FOR ATIO is limited to 10%. The maximum duty cycle limit increases linearly between 1V and 2.5V, reaching its final value of 90% when RUN/SS is above 2.5V. Somewhere before this point, the feedback amplifier ...

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LTC1703 U U APPLICATIO S I FOR ATIO LTC1703 remains in continuous mode. See the Inductor Selection section for a detailed description of ripple current. As the output load current decreases in continuous mode, the average current in the inductor ...

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U U APPLICATIO S I FOR ATIO Burst Mode Operation Discontinuous mode removes a loss term due to resistive drop in QB, but the LTC1703 is still switching QT and QB on and off once a cycle. Each time an ...

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LTC1703 U U APPLICATIO S I FOR ATIO internal latch. This latch releases the pull-down at FAULT, allowing the 10µA pull-up to take it high. When FAULT goes high, the LTC1703 stops all switching, turns both QB (bottom synchronous) MOSFETs ...

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U U APPLICATIO S I FOR ATIO use in LTC1703 circuits running from a 5V supply. As current flows through this resistance while the MOSFET is 2 on, it generates I R watts of heat, where I is the current ...

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LTC1703 U U APPLICATIO S I FOR ATIO At the same time, the input supply needs to supply several amps of current without excessive voltage drop. The input supply must have regulation adequate to prevent sudden load changes from causing ...

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U U APPLICATIO S I FOR ATIO At some random time after they are turned on, they can blow up for no apparent reason. The capacitor manufac- turers are aware of this and sell special “surge tested” tantalum capacitors specifically ...

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LTC1703 U U APPLICATIO S I FOR ATIO from C (time point A). 50% of the way through, TG2 IN turns on and the total current is 13A (time point B). Shortly thereafter, TG1 turns off and the current drops ...

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U U APPLICATIO S I FOR ATIO FEEDBACK LOOP/COMPENSATION Feedback Loop Types In a typical LTC1703 circuit, the feedback loop consists of the modulator, the external inductor and output capacitor, and the feedback amplifier and its compensation network. All of ...

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LTC1703 U U APPLICATIO S I FOR ATIO – REF Figure 10a. Type 2 Amplifier Schematic Diagram GAIN (dB) –6dB/OCT GAIN 0 –6dB/OCT PHASE Figure 10b. Type 2 Amplifier Transfer Function ...

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... W U V(OUT) in degrees. Refer to your SPICE manual for details of how to generate this plot. *1703 modulator gain/phase © * 1999 Linear Technology *this file written to run with PSpice 8.0 *may require modifications for other SPICE simulators *MOSFETs rfet mod sw 0.02 *inductor lext sw out1 1u rl out1 out 0 ...

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LTC1703 U U APPLICATIO S I FOR ATIO Now calculate the remaining values constant used in the calculations) ƒ = chosen crossover frequency (GAIN/20 (this converts GAIN absolute gain) ...

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U U APPLICATIO S I FOR ATIO Accuracy Trade-Offs The V sensing scheme used in the LTC1703 is not DS particularly accurate, primarily due to uncertainty in the R from MOSFET to MOSFET. A second error term DS(ON) arises from ...

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LTC1703 U U APPLICATIO S I FOR ATIO OPTIMIZING PERFORMANCE 2-Step Conversion The LTC1703 is ideally suited for use in 2-step conversion systems. 2-step systems use a primary regulator to con- vert the input power source (batteries or AC line ...

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U U APPLICATIO S I FOR ATIO efficiency, since a significant fraction of the total power is drawn from the 3.3V and 5V rails in a typical system. The correct way to calculate system efficiency is to calculate the power ...

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LTC1703 U U APPLICATIO S I FOR ATIO discontinuous mode happens when Burst Mode operation is invoked. At typical power levels, when Burst Mode operation is activated, gate drive is the dominant loss term. Burst Mode operation turns off all ...

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U U APPLICATIO S I FOR ATIO Very quickly, the feedback loop will realize that something has changed and will move at the bandwidth allowed by the external compensation network towards a new duty cycle. If the bandwidth is set ...

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LTC1703 U U APPLICATIO S I FOR ATIO capacitors and/or paralleling multiple capacitors at the output. The capacitance value accounts for the rest of the voltage drop until the inductor current rises. With most output capacitors, several devices paralleled to ...

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U U APPLICATIO S I FOR ATIO specified tolerance, the output voltage will ride high when I is low and will ride low when I LOAD LOAD to a traditional regulator, a voltage positioning regulator can theoretically stand as much ...

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LTC1703 U TYPICAL APPLICATIO S 32 1703fa ...

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U TYPICAL APPLICATIO S LTC1703 1703fa 33 ...

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LTC1703 U TYPICAL APPLICATIO S 0.1µF 0.1µF 10k – ® LT 1006 10k + 0.1µ SENSE 330pF 11k FB1 120pF 220pF COMP1 47k RUN/SS1 330pF 11k 0.1µF RUN/SS2 FB2 20k 220pF 120pF COMP2 10k 10k 47k I MAX1 ...

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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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... SOT-23 Step-Down Controller LTC1873 Dual 550kHz Synchronous 2-Phase Switching Regulator Controller with VRM 8.4 5-Bit VID LTC1929 2-Phase, Synchronous High Efficiency Converter trademark of Linear Technology Corporation. SENSE Linear Technology Corporation 36 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...