LTC1538CG-AUX Linear Technology, LTC1538CG-AUX Datasheet

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... The operating current levels are user-programmable via external current sense resistors. Wide input supply range allows operation from 3.5V to 30V (36V maximum). , LTC and LT are registered trademarks of Linear Technology Corporation. Adaptive Power is a trademark of Linear Technology Corporation CMDSH-3 ...

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... Junction Temperature (Note 1) ............................ 125 C + 0.3V to – 0.3V CC Storage Temperature Range ................ – 150 C to – 0.3V CC Lead Temperature (Soldering, 10 sec)................. 300 ORDER PART NUMBER 1 RUN/SS1 + 2 SENSE 1 – SENSE 1 3 LTC1538CG-AUX 4 V LTC1538IG-AUX PROG1 5 I TH1 6 POR1 7 C OSC SGND 8 9 LBI 10 LBO 11 SFB1 ...

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ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER Main Control Loops I V Feedback Current IN OSENSE2 V Regulated Output Voltage OUT1,2 1.19V (Adjustable) Selected 3.3V Selected 5V Selected V Reference Voltage Line Regulation LINEREG1,2 V Output Voltage Load Regulation LOADREG1,2 V Secondary Feedback ...

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... AUXFB Voltage AUXFB V AUXFB Divider Disconnect Voltage THAUXDR The denotes specifications which apply over the full operating temperature range. Note calculated from the ambient temperature T J dissipation P according to the following formulas: D LTC1538CG-AUX )(95 C/ LTC1539CGW )(85 C/ Note 2: The LTC1538-AUX and LTC1539 are tested in a feedback loop ...

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... Input Supply Current vs Input Voltage 2.5 2.0 5V, 3.3V OFF 5V STANDBY 1.5 5V, 3.3V ON 1.0 5V OFF, 3.3V ON 0.5 5V ON, 3.3V OFF INPUT VOLTAGE (V) LTC1538/39 • TPC07 Adaptive Power and Burst Mode are trademarks of Linear Technology Corporation. Efficiency vs Input Voltage OUT 100 V OUT LOAD 100mA LOAD ...

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LTC1538-AUX/LTC1539 W U TYPICAL PERFORMANCE CHARACTERISTICS Normalized Oscillator Frequency vs Temperature –5 –10 – 40 – 110 135 TEMPERATURE ( C) 1538/39 • G10 Maximum Current Comparator Threshold Voltage vs Temp 154 ...

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W U TYPICAL PERFORMANCE CHARACTERISTICS Auxiliary Regulator Sink Current Available AUX DR VOLTAGE ( PIN FUNCTIONS V : Main Supply Pin. Must be closely decoupled to ...

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LTC1538-AUX/LTC1539 PIN FUNCTIONS + + SENSE 1, SENSE 2: The (+) Input to Each Current Comparator. Built-in offsets between SENSE + SENSE 1 pins in conjunction with R trip threshold (same for second controller Receives ...

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PIN FUNCTIONS noninverting input of a comparator whose inverting input is tied to the internal 1.19V reference. See Auxiliary Regu- lator Application section. AUXON: Pulling this pin high turns on the auxiliary regu- lator/comparator. The threshold is ...

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LTC1538-AUX/LTC1539 U OPERATION (Refer to Functional Diagram) Main Control Loop The LTC1538-AUX/LTC1539 use a constant frequency, current mode step-down architecture. During normal op- eration, the top MOSFET is turned on each cycle when the oscillator sets the RS latch and ...

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U OPERATION (Refer to Functional Diagram) Frequency Synchronization A Phase-Locked Loop (PLL) is available on the LTC1539 to allow the oscillator to be synchronized to an external source connected to the PLLIN pin. The output of the phase detector at ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION Allowing some margin for variations in the LTC1538-AUX/ LTC1539 and external component values yield: 100 mV R SENSE I MAX The LTC1538-AUX/LTC1539 work well with values of R from 0.005 to 0.2 . SENSE C ...

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U U APPLICATIONS INFORMATION when the inductor current reaches zero while the bottom MOSFET is on. Lower inductor values (higher I this to occur at higher load currents, which can cause a dip in efficiency in the upper range of ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION The MOSFET power dissipations at maximum output current are given by OUT MAIN MAX 1. MAX RSS V – V ...

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U U APPLICATIONS INFORMATION higher price. Once the ESR requirement for C met, the RMS current rating generally far exceeds the I requirement. RIPPLE(P-P) In surface mount applications multiple capacitors may have to be paralleled to meet the ESR or ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION LTC1538-AUX + V IN LTC1539 TGL1 N-CH • EXTV CC TGS1* N-CH R6 SW1 SFB1 BG1 N-CH R5 SGND PGND OPTIONAL EXTV *TGS1 ONLY AVAILABLE ON THE LTC1539 CC CONNECTION 5V ...

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U U APPLICATIONS INFORMATION (DC) and the V pin is connected to the feedback OSENSE2 resistors as shown in Figure 5b. Controller 2 will force the externally attenuated output voltage to 1.19V. Power-On Reset Function (POR) The power-on reset function ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION 1 0.7 0 0.5 1.0 1.5 V (V) PLLLPF Figure 7. Operating Frequency vs V Phase-Locked Loop and Frequency Synchronization The LTC1539 has an internal voltage-controlled oscillator and phase detector comprising a phase-locked ...

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U U APPLICATIONS INFORMATION stable input to the voltage-controlled oscillator. The filter components C and R determine how fast the loop LP LP acquires lock. Typically 10k and C LP The low side of the filter needs to ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION With the addition of an external PNP pass device, a linear regulator capable of supplying up to 0.5A is created. As shown in Figure 11a, the base of the external PNP con- nects to the ...

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U U APPLICATIONS INFORMATION where L1, L2, etc. are the individual losses as a percentage of input power. Although all dissipative elements in the circuit produce losses, four main sources usually account for most of the losses in LTC1538-AUX/LTC1539 circuits. ...

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LTC1538-AUX/LTC1539 APPLICATIONS INFORMATION 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 during operation. ...

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U U APPLICATIONS INFORMATION With the 0.033 sense resistor I SC(AVG) increasing the Si4412DY dissipation to 950mW at a die temperature of 105 C. C will require an RMS current rating of at least 1. temperature and C ...

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LTC1538-AUX/LTC1539 U U APPLICATIONS INFORMATION turns ratio for the secondary flyback winding. Keep these switch-node-related PC traces small and away from the “quiet” side of the IC (not just above and below each other on the opposite side of the ...

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U U APPLICATIONS INFORMATION 0. 10k C SS 0.1 F 1000pF 1000pF C C1B 220pF C C1A INTV 1000pF 100k 10k IN OSC C C2B 470pF C C2A R INT V ...

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LTC1538-AUX/LTC1539 U TYPICAL APPLICATIONS 26 + ...

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U TYPICAL APPLICATIONS LTC1538-AUX/LTC1539 27 ...

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LTC1538-AUX/LTC1539 U TYPICAL APPLICATIONS 28 ...

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U TYPICAL APPLICATIONS LTC1538-AUX/LTC1539 29 ...

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LTC1538-AUX/LTC1539 U PCB LAYOUT A D FIL Silkscreen Top Copper Layer 1 Copper Layer (Gerber files for this circuit board are available. Call the LTC factory.) Silkscreen Bottom Copper Layer 2 Ground Plane Copper Layer 4 ...

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... SHALL NOT EXCEED 0.006" (0.152mm) 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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... High Frequency, Small Inductor, High Efficiency Switchers, 1.5A Switch High Efficiency 5V to 3.3V Conversion 15A 16-Pin Narrow SO and SSOP Packages Full-Featured Single Controllers Shutdown Current < Shutdown Current < Power-On Reset Eliminated 1.3A, Li-Ion, NiCd, NiMH, Pb-Acid Charger LT/GP 0896 7K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1996 ...