lt3579iufd-trpbf Linear Technology Corporation, lt3579iufd-trpbf Datasheet
lt3579iufd-trpbf
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lt3579iufd-trpbf Summary of contents
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DC/DC Converter with Fault Protection FEATURES n 6A, 42V Combined Power Switch n Output Short Circuit Protection n Wide Input Range: 2.5V to 16V Operating, 40V Maximum Transient n LT3579-1: Dual-Phase Capable n Master/Slave (3.4A/2.6A) Switch Design n User Confi ...
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... LT3579EUFD-1#PBF LT3579EUFD-1#TRPBF LT3579IUFD-1#PBF LT3579IUFD-1#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: 2 FAULT ......................................................... – ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T PARAMETER Minimum Input Voltage V Overvoltage Lockout IN Positive Feedback Voltage Negative Feedback Voltage Positive FB Pin Bias Current Negative FB Pin Bias Current Error Amp Transconductance Error Amp Voltage ...
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LT3579/LT3579-1 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T PARAMETER Soft-Start Charge Current Soft-Start Discharge Current Soft-Start High Detection Voltage Soft-Start Low Detection Voltage SHDN Minimum Input Voltage High SHDN Input Voltage Low SHDN Pin Bias Current CLKOUT ...
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TYPICAL PERFORMANCE CHARACTERISTICS Switch Current Limit DUTY CYCLE (%) 35791 G01 Switch Current Limit vs Temperature ...
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LT3579/LT3579-1 TYPICAL PERFORMANCE CHARACTERISTICS CLKOUT Rise Time at 1MHz CLKOUT RISE TIME CLKOUT FALL TIME 100 150 200 CLKOUT CAPACITIVE LOAD (pF) 35791 G10 Active/Lockout Threshold 1.4 ...
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PIN FUNCTIONS (QFN/TSSOP) GATE (Pin 1/Pin 3): PMOS Gate Drive Pin. The GATE pin is a pull-down current source, and can be used to drive the gate of an external PMOS transistor for output short circuit protection or output disconnect. ...
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LT3579/LT3579-1 BLOCK DIAGRAM GATE 933μA SOFT- START V C 2.1V + 50mV – 1.8V 250k SHDN – 1.33V UVLO V IN 1.215V REFERENCE + 14.6k A1 – 14.6k A2 – ...
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STATE DIAGRAM SHDN > 1.33V DROPS CAUSING: OUT FB < 1.17V (BOOST > 45mV (INVERTING) FAULT1 = OVER VOLTAGE PROTECTION ON V OVER TEMPERATURE (T JUNCTION OVER CURRENT ON SW1 (I SW1 OVER VOLTAGE PROTECTION ...
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LT3579/LT3579-1 OPERATION OPERATION – OVERVIEW The LT3579 uses a constant-frequency, current mode control scheme to provide excellent line and load regulation. The part’s undervoltage lockout (UVLO) function, together with soft-start and frequency foldback, offers a controlled means of starting up. ...
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OPERATION Sample Mode Sample Mode is the mechanism used by the LT3579 to aid in the detection of output shorts. It refers to a state of the LT3579 where the master and slave power switches (Q1 and Q2) are turned ...
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LT3579/LT3579-1 OPERATION When a fault is detected, in addition to the FAULT pin being pulled low internally, the LT3579 also disables its CLKOUT pin, turns off its power switches, and the GATE pin becomes high impedance (refer to the State ...
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APPLICATIONS INFORMATION BOOST CONVERTER COMPONENT SELECTION D1 L1 30V, 4A 2.2μ OUT1 10μ 130k SW1 SW2 100k FAULT GATE LT3579 200k SHDN CLKOUT 22μF SYNC GND ...
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LT3579/LT3579-1 APPLICATIONS INFORMATION SEPIC CONVERTER COMPONENT SELECTION – COUPLED OR UN-COUPLED INDUCTORS 4.7μF 60V, 3A 6.8μH V PWR 9V TO 16V C PWR L2 4.7μF 6.8μH V SW1 SW2 SHDN ...
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APPLICATIONS INFORMATION DUAL INDUCTOR INVERTING CONVERTER COMPONENT SELECTION – COUPLED OR UN-COUPLED INDUCTORS C1 L1 4.7μF 3.3μ SW1 SW2 SHDN C GATE IN 22μF LT3579 100k FAULT CLKOUT SYNC GND SS ...
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LT3579/LT3579-1 APPLICATIONS INFORMATION LAYOUT GUIDELINES FOR BOOST, SEPIC, AND DUAL INDUCTOR INVERTING TOPOLOGIES General Layout Guidelines • To optimize thermal performance, solder the exposed ground pad of the LT3579 to the ground plane with multiple vias around the pad connecting ...
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APPLICATIONS INFORMATION Inverting Topology Specifi c Layout Guidelines • Keep ground return path from the cathode of D1 (to chip) separated from output capacitor C return path (to chip) in order to minimize switching noise coupling into the output. Notice ...
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LT3579/LT3579-1 APPLICATIONS INFORMATION C – A– RETURN C GROUND DIRECTLY TO LT3579 EXPOSED PAD PIN 21 ADVISED TO NOT COMBINE C IN B– RETURN C GROUND DIRECTLY TO LT3579 EXPOSED PAD PIN 21 ...
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APPLICATIONS INFORMATION The following example calculates the power dissipation in the LT3579 for a particular boost application 5V 12V 1.5A OUT OUT V = 0.5V 0.185V). D CESAT To calculate ...
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LT3579/LT3579-1 APPLICATIONS INFORMATION The published (http://www.linear.com/designtools/ packaging/Linear_Technology_Thermal_Resistance_ Table.pdf) θ value is 38°C/W for the TSSOP Exposed Pad JA package and 34°C/W for the 4mm × 5mm QFN package. In practice, lower θ values are realizable if board layout is JA ...
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APPLICATIONS INFORMATION Clock Synchronization An external source can set the operating frequency of the LT3579 by providing a digital clock signal into the SYNC pin (R resistor still required). The LT3579 will operate at T the SYNC clock frequency. The ...
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LT3579/LT3579-1 APPLICATIONS INFORMATION Use the following equations to calculate the FB resistor for 2-phase converters: ⎛ ⎞ V – 215 V OUT R = ⎜ ⎟ ; Boost or SEPIC μA • ⎝ ...
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APPLICATIONS INFORMATION HOT PLUG The high inrush current associated with hot-plugging V can be largely rejected with the use of an external PMOS. A simple hot-plug controller can be designed by connecting an external PMOS in series with V IN ...
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LT3579/LT3579-1 APPENDIX SETTING THE OUTPUT VOLTAGE The output voltage is set by connecting a resistor (R from V to the FB pin determined from the OUT FB following equation – OUT ...
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APPENDIX Table 5. Inductor Manufacturers Vishay IHLP-2020BZ-01 and IHLP-2525CZ-01 Series Coilcraft XLP , MLC and MSS Series Cooper Bussmann DRQ125 and DRQ127 Series Sumida CDRH series TDK RLF and SLF series Würth WE-PD, WE-PDF , WE-HC and WE-DD Series Minimum ...
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LT3579/LT3579-1 APPENDIX Maximum Inductance Excessive inductance can reduce ripple current to levels that are diffi cult for the current comparator (A4 in the Block Diagram) to cleanly discriminate, thus causing duty cycle jitter and/or poor regulation. The maximum inductance can ...
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APPENDIX Table 6 shows a list of several ceramic capacitor man- ufacturers. Consult the manufacturers for detailed infor- mation on their entire selection of ceramic parts. Table 6. Ceramic Capacitor Manufacturers TDK www.tdk.com Murata www.murata.com Taiyo Yuden www.t-yuden.com PMOS SELECTION ...
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LT3579/LT3579-1 APPENDIX Table 7 shows a list of several discrete PMOS manufa- cturers. Consult the manufacturers for detailed information on their entire selection of PMOS devices. Table 7. Discrete PMOS Manufacturers Vishay www.vishay.com Fairchild Semiconductor www.fairchildsemi.com Central Semiconductor www.centralsemi.com COMPENSATION ...
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APPENDIX feedback loop. As with any feedback loop, identifying the gain and phase contribution of the various elements in the loop is critical. Figure 18 shows the key equivalent elements of a boost converter. Because of the fast current control ...
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LT3579/LT3579-1 APPENDIX The current mode zero (Z3 right half plane zero which can be an issue in feedback control design, but is manageable with proper external component selection. Using the circuit in Figure example, Table ...
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TYPICAL APPLICATION 1MHz 12V Boost Converter can Survive Output Shorts Output Short V OUT 10V/DIV CLKOUT 2V/DIV I L 2A/DIV FAULT 5V/DIV 10μs/DIV L1 D1 2.2μH C OUT1 10μF 130k SW1 SW2 ...
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LT3579/LT3579-1 TYPICAL APPLICATION 500kHz SEPIC Converter Generates 3.3V from 33V Input V BAT 3V TO 33V (OPERATING 16V (START-UP) 200k D1 15V C1: 10nF , 16V, X7R, 0603 D1: CENTRAL SEMI CMHZ5245B-LTZ ...
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TYPICAL APPLICATION Effi ciency and Power Loss 100 0.25 0.5 0.75 LOAD CURRENT (A) 1.2MHz -12V Inverting Converter 4.7μF 3.3μH 3.3μH D1 SW1 ...
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LT3579/LT3579-1 TYPICAL APPLICATION VFD (Vacuum Flourescent Display) Power Supply Switches at 1MHz Danger High Voltage! Operation by High Voltage Trained Personnel Only 16V C IN 10μ 10μF , 25V, X7R, 1210 IN C1-C6: 2.2μF ...
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TYPICAL APPLICATION Effi ciency and Power Loss 100 200 300 LOAD CURRENT (mA) 1MHz ±12V Converter C2 4.7μ R1** C1 1.2k ...
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LT3579/LT3579-1 TYPICAL APPLICATION 1MHz, 2-Phase Converter Generates a 24V Output from 16V Input and Uses Small Components V PWR 8V TO 16V PWR V OUT1 500k C 4.7μ 10μF ...
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TYPICAL APPLICATION 2MHz, Boost Converter with Output Disconnect Generates a 5V Output from 2.8V to 4.2V Input V 2.8V TO 4.2V Effi ciency and Power Loss 100 3. ...
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LT3579/LT3579-1 PACKAGE DESCRIPTION 6.60 ±0.10 4.50 ±0.10 SEE NOTE 4 RECOMMENDED SOLDER PAD LAYOUT 4.30 – 4.50* (.169 – .177) 0.09 – 0.20 0.50 – 0.75 (.0035 – .0079) (.020 – .030) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE ...
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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. UFD Package 20-Lead Plastic QFN (4mm × ...
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... LOAD CURRENT (A) 3579 TA08 = 42V 1.9mA < 1μA, 4mm × 3mm DFN-14 42V 1mA < 1μA, 3mm × 3mm DFN- 40V 5mA < 1μA, 4mm × 3mm DFN-14 0410 • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2010 35791f ...