LT3758EMSE#PBF Linear Technology, LT3758EMSE#PBF Datasheet
LT3758EMSE#PBF
Specifications of LT3758EMSE#PBF
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LT3758EMSE#PBF Summary of contents
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... The LT3758 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and No R SENSE trademarks are the property of their respective owners. Patents pending. ...
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... EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LT3758EDD#PBF LT3758EDD#TRPBF LT3758IDD#PBF LT3758IDD#TRPBF LT3758EMSE#PBF LT3758EMSE#TRPBF LT3758IMSE #PBF LT3758IMSE#TRPBF LT3758HMSE#PBF LT3758HMSE#TRPBF LT3758MPMSE #PBF LT3758MPMSE#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. ...
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ELECTRICAL CHARACTERISTICS erature range, otherwise specifi cations are at T PARAMETER V Operating Range IN V Shutdown Operating Operating I with Internal LDO Disabled IN Q SENSE Current Limit Threshold SENSE Input ...
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LT3758 ELECTRICAL CHARACTERISTICS erature range, otherwise specifi cations are at T PARAMETER INTV Current in Shutdown CC INTV Voltage to Bypass Internal LDO CC Logic Inputs SHDN/UVLO Threshold Voltage Falling SHDN/UVLO Input Low Voltage SHDN/UVLO Pin Bias Current Low SHDN/UVLO ...
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TYPICAL PERFORMANCE CHARACTERISTICS Positive Feedback Voltage vs Temperature 1605 V IN 1600 V = 24V IN 1595 1590 V IN SHDN/UVLO = 1.33V 1585 1580 –75 –50 – TEMPERATURE (°C) Quiescent ...
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LT3758 TYPICAL PERFORMANCE CHARACTERISTICS Switching Frequency vs Temperature 330 R = 41.2K T 320 310 300 290 280 270 –75 –50 – TEMPERATURE (°C) SENSE Current Limit Threshold vs Duty Cycle 115 110 105 100 ...
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TYPICAL PERFORMANCE CHARACTERISTICS INTV vs Temperature CC 7.4 7.3 7.2 7.1 7.0 –75 –50 – 100 125 150 TEMPERATURE (°C) 3758 G13 INTV Line Regulation CC 7.30 7.25 7.20 7.15 7. ...
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LT3758 PIN FUNCTIONS VC (Pin 1): Error Amplifi er Compensation Pin. Used to stabilize the voltage loop with an external RC network. FBX (Pin 2): Positive and Negative Feedback Pin. Receives the feedback voltage from the external resistor divider across ...
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BLOCK DIAGRAM 2.5V 2μA 2. A11 – 1.72V + G6 A12 – + –0.88V + 1.6V A1 – FBX FBX – –0.8V FREQUENCY FOLDBACK 3 Figure 1. ...
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LT3758 APPLICATIONS INFORMATION Main Control Loop The LT3758 uses a fi xed frequency, current mode control scheme to provide excellent line and load regulation. Op- eration can be best understood by referring to the Block Diagram in Figure 1. The ...
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APPLICATIONS INFORMATION INTV Regulator Bypassing and Operation CC An internal, low dropout (LDO) voltage regulator produces the 7.2V INTV supply which powers the gate driver shown in Figure 1. The LT3758 contains an undervoltage lockout comparator A8 and ...
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LT3758 APPLICATIONS INFORMATION As illustrated in Figure 2, a trade-off between the operating frequency and the size of the power MOSFET may be needed in order to maintain a reliable IC junction temperature. Prior to lowering the operating frequency, however, ...
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APPLICATIONS INFORMATION The operating frequency of the LT3758 can be synchronized to an external clock source. By providing a digital clock signal into the SYNC pin, the LT3758 will operate at the SYNC clock frequency. If this feature is used, ...
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LT3758 APPLICATIONS INFORMATION FBX Frequency Foldback When V is very low during start- GND fault on OUT the output, the switching regulator must operate at low duty cycles to maintain the power switch current within the current limit ...
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APPLICATIONS INFORMATION switch ripple current percentage can be calculated using the following equation: Δ V SENSE χ = − Δ • V SENSE χ is used in subsequent design examples to calculate inductor value. ΔV ...
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LT3758 APPLICATIONS INFORMATION The constant χ in the preceding equation represents the percentage peak-to-peak ripple current in the inductor, relative L(MAX) The inductor ripple current has a direct effect on the choice of the inductor value. Choosing ...
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APPLICATIONS INFORMATION The used in this equation normally includes the θJA R for the device plus the thermal resistance from the board θJC to the ambient temperature in the enclosure. T exceed the diode maximum junction temperature ...
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LT3758 APPLICATIONS INFORMATION The fl yback converter can be designed to operate either in continuous or discontinuous mode. Compared to continuous mode, discontinuous mode has the advantage of smaller transformer inductances and easy loop compensation, and the disadvantage of higher ...
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APPLICATIONS INFORMATION Flyback Converter: Transformer Design for Discontinuous Mode Operation The transformer design for discontinuous mode of opera- tion is chosen as presented here. According to Figure 8, the minimum D3 (D3 ) occurs when the the converter MIN has ...
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LT3758 APPLICATIONS INFORMATION L is the leakage inductance of the primary winding, LK which is usually specifi the transformer character- istics. L can be obtained by measuring the primary LK inductance with the secondary windings shorted. The snubber ...
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APPLICATIONS INFORMATION Flyback Converter: Input Capacitor Selection The input capacitor in a fl yback converter is subject to a large RMS current due to the discontinuous primary current. To prevent large voltage transients, use a low ESR input capacitor sized ...
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LT3758 APPLICATIONS INFORMATION ΔI requires large inductances and reduces the current L loop gain (the converter will approach voltage mode). Accepting larger values of ΔI allows the use of low L inductances, but results in higher input current ripple and ...
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APPLICATIONS INFORMATION MOSFET, its junction temperature can be obtained using the following equation: • θ • (θ FET JA A FET T must not exceed the MOSFET maximum junction ...
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LT3758 APPLICATIONS INFORMATION Inverting Converter: Inductor, Sense Resistor, Power MOSFET, Output Diode and Input Capacitor Selections The selections of the inductor, sense resistor, power MOSFET, output diode and input capacitor of an inverting converter are similar to those of the ...
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APPLICATIONS INFORMATION Check the stress on the power MOSFET by measuring its drain-to-source voltage directly across the device terminals (reference the ground of a single scope probe directly to the source pad on the PC board). Beware of inductive ringing, ...
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LT3758 APPLICATIONS INFORMATION Recommended Component Manufacturers Some of the recommended component manufacturers are listed in Table 2. Table 2. Recommended Component Manufacturers VENDOR AVX BH Electronics Coilcraft Cooper Bussmann Diodes, Inc Fairchild General Semiconductor International Rectifi er IRC Kemet Magnetics ...
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TYPICAL APPLICATIONS V IN 10V TO 40V C 4.7μF 50V X7R R T 41.2k 300kHz OUT1 Effi ciency vs Output Current 100 40V 24V ...
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LT3758 TYPICAL APPLICATIONS V IN 36V TO 72V C IN 2.2μF 100V X7R 63.4k 200kHz C : MURATA GRM32ER72A225KA35L IN T1: COILTRONICS VP2-0066 M1: VISHAY SILICONIX SI4848DY Effi ciency vs Output Current 100 V = 48V ...
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TYPICAL APPLICATIONS VFD (Vacuum Fluorescent Display) Flyback Power Supply 16V C IN 22μF 178k 25V 32.4k 0.47μF 63.4k 200kHz C : MURATA GRM32ER61E226KE15L MURATA GRM31CR72A105K01L OUT1 C : MURATA GRM32ER72A225KA35L OUT2 D1: VISHAY ...
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LT3758 TYPICAL APPLICATIONS 36V to 72V Input, 3.3V Output Isolated Telecom Power Supply V IN 36V TO 72V C IN 2.2μF 100V X7R SHDN/UVLO SENSE 44.2k LT3758 SYNC INTV FBX RT SS GND 63.4k 200kHz 0.47μF 30 ...
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TYPICAL APPLICATIONS V IN 18V TO 72V C 2.2μF 100V X7R 41.2k 300kHz TAIYO YUDEN HMK325B7225KN MURATA GRM31CR61E106KA12L OUT Effi ciency vs Output Current 100 18V ...
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LT3758 TYPICAL APPLICATIONS V IN 10V TO 40V C IN 4.7μF 50V X7R 2 41.2k 300kHz MURATA GRM32ER71H475KA88L MURATA GRM32ER61C226KE20 OUT D1: VISHAY SILICONIX 30BQ060 Effi ciency vs Output Current 100 V ...
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PACKAGE DESCRIPTION 3.55 0.05 1.65 0.05 2.15 0.05 (2 SIDES) 0.25 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PIN 1 TOP MARK (SEE NOTE 6) 0.200 REF DD Package 10-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1699 ...
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LT3758 PACKAGE DESCRIPTION 2.794 0.102 (.110 .004) 5.23 (.206) MIN 0.305 0.038 (.0120 .0015) TYP RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 0.254 (.010) GAUGE PLANE 0.18 (.007) NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES ...
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... Revised penultimate sentence of Operating Frequency and Synchronization section 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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... DFN, 10-Lead MSOP-E Packages www.linear.com ● Effi ciency vs Output Current 100 42V OUT V = 72V 12V 0.001 0.01 0.1 1 OUT2 10μF OUTPUT CURRENT (A) 16V X5R 4 ≤ 36V, Burst Mode ® Operation 0510 REV B • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2009 10 3757 TA08b 3758fb ...