LTC1871EMS-1 Linear Technology Corporation, LTC1871EMS-1 Datasheet
LTC1871EMS-1
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LTC1871EMS-1 Summary of contents
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... For applications requiring primary- to-secondary side isolation, please refer to the LTC1871 datasheet. The LTC1871-1 is available in the 10-lead MSOP package. L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation trademark of Linear Technology Corporation. All other trademarks are the SENSE property of their respective owners ...
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... LTC1871IMS-1#PBF LTC1871IMS-1#TRPBF LEAD BASED FINISH TAPE AND REEL LTC1871EMS-1 LTC1871EMS-1#TR LTC1871IMS-1 LTC1871IMS-1#TR Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER + V Rising RUN Input Threshold Voltage RUN – V Falling RUN Input Threshold Voltage RUN V RUN Pin Input Threshold Hysteresis RUN(HYST) I RUN Input Current RUN ...
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LTC1871-1 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER Low Dropout Regulator V INTV Regulator Output Voltage INTVCC CC ΔV INTV Regulator Line Regulation INTVCC CC ΔV IN1 ΔV INTV Regulator Line Regulation INTVCC CC ΔV ...
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TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Mode (V) IN 18711 G04 Burst Mode I vs Temperature Q 500 400 300 200 100 0 –50 – ...
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LTC1871-1 TYPICAL PERFORMANCE CHARACTERISTICS Frequency vs Temperature 325 320 315 310 305 300 295 290 285 280 275 –50 100 125 150 – TEMPERATURE (°C) 18711 G13 INTV Load Regulation 7.5V IN 5.2 ...
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PIN FUNCTIONS MODE/SYNC (Pin 5): This input controls the operating mode of the converter and allows for synchronizing the operating frequency to an external clock. If the MODE/ SYNC pin is connected to ground, Burst Mode operation is enabled. If ...
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LTC1871-1 OPERATION Main Control Loop The LTC1871 constant frequency, current mode controller for DC/DC boost, SEPIC and fl yback converter applications. The LTC1871-1 is distinguished from con- ventional current mode controllers because the current control loop can be ...
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OPERATION Programming the Operating Mode For applications where maximizing the effi ciency at very light loads (e.g., <100μ high priority, the current in the output divider could be decreased to a few micro- amps and Burst Mode operation ...
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LTC1871-1 APPLICATIONS INFORMATION When the oscillator’s internal logic circuitry detects a synchronizing signal on the MODE/SYNC pin, the in- ternal oscillator ramp is terminated early and the slope compensation is increased by approximately 30 result, in applications requiring ...
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APPLICATIONS INFORMATION – 1.230V + R2 Figure 7. Bypassing the LDO Regulator and Gate Driver Supply As a result, high input voltage applications in which a large power MOSFET is being driven at high frequencies can cause the LTC1871-1 to ...
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LTC1871-1 APPLICATIONS INFORMATION error caused by the current fl owing into the FB pin dur- ing normal operation is less than 1% (this translates to a maximum value about 250k). Programming Turn-On and Turn-Off Thresholds with the ...
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APPLICATIONS INFORMATION Application Circuits A basic LTC1871-1 application circuit is shown in Figure 1. External component selection is driven by the characteristics of the load and the input supply. The fi rst topology to be analyzed will be the boost ...
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LTC1871-1 APPLICATIONS INFORMATION Remember that boost converters are not short-circuit protected. Under a shorted output condition, the inductor current is limited only by the input supply capability. For applications requiring a step-up converter that is short- circuit protected, please refer ...
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APPLICATIONS INFORMATION from a lithium-ion battery or a 3.3V logic supply), then sublogic-level threshold MOSFETs should be used. Pay close attention to the BV DSS MOSFETs relative to the maximum actual switch voltage in the application. Many logic-level devices are ...
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LTC1871-1 APPLICATIONS INFORMATION for V and the R of the MOSFET listed in SENSE(MAX) DS(ON) the manufacturer’s data sheet. The power dissipated by the MOSFET in a boost converter is O(MAX • R • D FET ...
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APPLICATIONS INFORMATION For many designs it is possible to choose a single capacitor type that satisfi es both the ESR and bulk C requirements for the design. In certain demanding applications, however, the ripple voltage can be improved signifi cantly ...
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LTC1871-1 APPLICATIONS INFORMATION Table 1. Recommended Component Manufacturers VENDOR AVX BH Electronics Coilcraft Coiltronics Diodes, Inc Fairchild General Semiconductor International Rectifi er IRC Kemet Magnetics Inc Microsemi Murata-Erie Nichicon On Semiconductor Panasonic Sanyo Sumida Taiyo Yuden TDK Thermalloy Tokin Toko ...
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APPLICATIONS INFORMATION Burst Mode operations begins, since it is the peak current that is being clamped. The output voltage ripple can increase during Burst Mode operation if ΔI is substantially less than I L occur if the input voltage is ...
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LTC1871-1 APPLICATIONS INFORMATION dissipated in this resistor would be 514mW at maxi- mum output current. Assuming an effi ciency of 90%, this sense resistor power dissipation represents 1.3% of the overall input power. In other words, for this ap- plication, ...
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APPLICATIONS INFORMATION The inductor ripple current is O(MAX) = • = 0.4 • 1– D 1– 0.39 MAX And so the inductor value is: V 3.3V IN(MIN • D MAX I • f ...
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LTC1871-1 APPLICATIONS INFORMATION PC Board Layout Checklist 1. In order to minimize switching noise and improve output load regulation, the GND pin of the LTC1871-1 should be connected directly to 1) the negative terminal of the INTV decoupling capacitor, 2) ...
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APPLICATIONS INFORMATION 2. Beware of ground loops in multiple layer PC boards. Try to maintain one central ground node on the board and use the input capacitor to avoid excess input ripple for high output current power supplies. If the ...
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LTC1871-1 APPLICATIONS INFORMATION SEPIC Converter Applications The LTC1871-1 is also well suited to SEPIC (single-ended primary inductance converter) converter applications. The SEPIC converter shown in Figure 16 uses two inductors. The advantage of the SEPIC converter is the input voltage ...
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APPLICATIONS INFORMATION The constant ‘χ’ represents the fraction of ripple current in the inductor relative to its maximum value. For example, if 30% ripple current is chosen, then χ = 0.30 and the peak current is 15% greater than the ...
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LTC1871-1 APPLICATIONS INFORMATION devices are limited to 30V or less. Check the switching waveforms directly across the drain and source terminals of the power MOSFET to ensure the V the maximum rating for the device. During the MOSFET’s on-time, the ...
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APPLICATIONS INFORMATION and the diode junction temperature is • TH(JA) The used in this equation normally includes TH(JA) the R for the device plus the thermal resistance from ...
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LTC1871-1 APPLICATIONS INFORMATION choice is AVX TPS series of surface mount tantalum. Also, ceramic capacitors are now available with extremely low ESR, ESL and high ripple current ratings. SEPIC Converter: Input Capacitor Selection The input capacitor of a SEPIC converter ...
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APPLICATIONS INFORMATION And so the inductor value is IN(MIN • D MAX 2 • I • • 1.5 • 300k L The component chosen Electronics BH510- 1007, which has a ...
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LTC1871-1 APPLICATIONS INFORMATION 12V OUT V (AC) OUT 200mV/DIV I OUT 0.5A/DIV 50μs/DIV Figure 19. LTC1871-1 SEPIC Converter Load Step Response 6. The diode for this design must handle a maximum DC output current ...
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TYPICAL APPLICATIONS R C 22k 6.8nF 12. 37.4k 80.6k 47pF SANYO POSCAP 6TPA47M SANYO POSCAP 6TPB150M OUT1 C : TAIYO YUDEN JMK316BJ106ML OUT2 C ...
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LTC1871-1 TYPICAL APPLICATIONS 18V to 27V Input, 28V Output, 400W 2-Phase, Low Ripple, Synchronized RF Base Station Power Supply (Boost 93.1k 8.45k RUN 47pF FREQ 5 R ...
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TYPICAL APPLICATIONS 4.5V to 28V Input, 5V/2A Output SEPIC Converter with Undervoltage Lockout and Soft-Start R1 115k 54.9k 4.7nF 1% 1 RUN 12k FREQ 49.9k 8.2nF ...
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LTC1871-1 TYPICAL APPLICATIONS 5V to 15V Input, – 5V/5A Output Positive-to-Negative Converter with Undervoltage Lockout and Level-Shifted Feedback R1 R2 154k C1 68.1k 1% 1nF 10k C C2 330pF C C1 10nF C : TDK C5750X5R1C476M IN ...
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... LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 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. ...
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... TA06 , 5V Gate Drive, Current Mode Control , 7V Gate Drive, Current Mode Control ≤ 16V, Miniature Design IN ≤ Current Mode Control, 50kHz to 1MHz ≤ 40V; 4A Gate Drive, 150kHz to 500kHz LT 0108 REV B • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2007 18711fb ...