ltc3521fe Linear Technology Corporation, ltc3521fe Datasheet
ltc3521fe
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ltc3521fe Summary of contents
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... GPS Receivers n L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected Patents, including 6404251, 6166527. Typical applicaTion ...
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... CONNECTION OPTIONAL) EXPOSED PAD (PIN 25) IS GND AND MUST BE SOLDERED TO PCB GROUND PART MARKING PACKAGE DESCRIPTION 3521 24-Lead (4mm × 4mm) Plastic QFN LTC3521FE 20-Lead Plastic TSSOP http://www.linear.com/leadfree/ http://www.linear.com/tapeandreel/ The denotes the specifications which apply over the full operating l = 25° ...
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T PARAMETER Oscillator Frequency SHDN1, SHDN2, SHDN3, PWM Input High Voltage SHDN1, SHDN2, SHDN3, PWM Input Low Voltage Power Good Outputs Low Voltage Power Good Outputs Leakage Current Buck Converters PMOS ...
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LTC3521 Typical perForMance characTerisTics Buck-Boost Efficiency, Li-Ion to 3.3V 100 V = 2.7V PWM MODE 4. Burst Mode 40 OPERATION 0 LOAD CURRENT (mA) Buck ...
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Typical perForMance characTerisTics Switching Frequency 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 1.8 2.3 2.8 3.3 3.8 4.3 4.8 5.3 V (V) IN 3521 G08 Burst Mode Quiescent Current ALL THREE ...
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LTC3521 Typical perForMance characTerisTics Buck-Boost Burst to PWM Transition INDUCTOR CURRENT 200mA/DIV V OUT 20mV/DIV 3521 G16 50µs/DIV 4.7µ 3. 22µF OUT OUT Buck-Boost Current Limit vs Temperature 2150 2100 ...
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FuncTions in overtemperature shutdown, the part is in undervoltage lockout the SHDN3 pin is pulled low. PGOOD2 (Pin 5/Pin 3): This pin is an open-drain output which pulls low under any of the following conditions: V buck ...
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LTC3521 pin FuncTions NC (Pin 19, UF Package Only): No Internal Connection. PV (Pin 20/Pin 22): High Current Power Supply Connec- IN2 tion Used to Supply the Buck Converter Power Switches. This pin should be bypassed by a 10µF or ...
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The LTC3521 combines dual synchronous buck DC/DC converters and a 4-switch buck-boost DC/DC converter in a 4mm × 4mm QFN package and a 20-pin thermally enhanced TSSOP package. The buck-boost converter utilizes a proprietary switching algorithm which allows its ...
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LTC3521 operaTion Soft-Start The buck converters have an internal voltage mode soft-start circuit with a nominal duration of 500μs. The converters remain in regulation during soft-start and will therefore respond to output load transients which occur during this time. In ...
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These advantages result in increased efficiency and stability in comparison to the traditional 4-switch buck-boost converter. Error Amplifier and Compensation The buck-boost converter utilizes a voltage mode error amplifier with an internal compensation network as shown in Figure ...
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LTC3521 operaTion Burst Mode Operation With the PWM pin held low, the buck-boost converter operates utilizing a variable frequency switching algorithm designed to improve efficiency at light load and reduce the standby current at zero load. In Burst Mode operation, ...
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The basic LTC3521 application circuit is shown as the Typical Application on the front page of this data sheet. The external component selection is determined by the desired output voltages, output currents and ripple volt- age requirements of ...
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LTC3521 applicaTions inForMaTion Buck Input Capacitor Selection The PV pin provides current to the buck converter power IN2 switch and is the supply pin for the IC’s internal circuitry recommended that a low ESR ceramic capacitor with a ...
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MHz and L is the inductance in μ – 1 OUT IN Δ • -P,BUCK ...
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LTC3521 applicaTions inForMaTion Capacitor Vendor Information Both the input and output capacitors used with the LTC3521 must be low ESR and designed to handle the large AC cur- rents generated by switching converters. The vendors in Table 5 provide capacitors ...
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MINIMIZE TRACE LENGTH MINIMIZE TRACE LENGTH SHDN2 (1) PGOOD3 (2) PGOOD2 (3) PGOOD1 ( (5) GND (6) DIRECT TIE BACK TO GND PIN MINIMIZE TRACE LENGTH UNINTERRUPTED GROUND PLANE MUST EXIST UNDER ALL COMPONENTS SHOWN IN ...
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LTC3521 Typical applicaTion Dual Supercapacitor to 3.3V at 200mA, 1.8V at 50mA and 1. 1. OUT1 3.3V 200mA Converter Output Voltages V IN 2V/DIV V OUT1 2V/DIV V OUT2 2V/DIV ...
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... ON THE TOP AND BOTTOM OF PACKAGE 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. FE Package 20-Lead Plastic TSSOP (4 ...
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... IN OUT(MAX 2.4V to 5.5V 5.25V 25µA, IN OUT(MAX 1.8V to 5.5V 5V 16µA, IN OUT(MIN 2.4V to 5.5V 2.4V to 5.25V, IN OUT(MIN) < 1µA, MS10 and DFN Packages SD : 2.5V to 5.5V 0.6V 40µA, IN OUT(MIN 0310 • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2010 3521 TA03b 3521f ...