SC4525ASETRT Semtech, SC4525ASETRT Datasheet

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POWER MANAGEMENT Features Wide input range 28V  3A Output Current  200kHz to 2MHz Programmable Frequency  Precision V Feedback Voltage  Peak Current-Mode Control  Cycle-by-Cycle Current Limiting  Hiccup Overload Protection with Frequency Foldback  ...

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... GND Pin SOIC - EDP) Marking Information yyww=Date code (Example: 0752) xxxxx=Semtech Lot No. (Example: E900) Ordering Information Device SC4525ASETRT BST SC4525AEVB FB Notes: COMP () Available in tape and reel only. A reel contains 2,500 devices. (2) Available in lead-free package only. Device is fully WEEE and RoHS SS/EN compliant ...

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Absolute Maximum Ratings V Supply Voltage ……………………………… -0.3 to 32V IN BST Voltage ……………………………………………… 42V BST Voltage above SW …………………………………… 34V SS Voltage ……………………………………………-0 Voltage …………………………………………… -0 Voltage ………………………………………… -0 Transient ...

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Electrical Characteristics (Cont.) Unless otherwise noted 2V 5V BST Parameter Minimum Switch On-time Minimum Switch Off-time Switch Leakage Current Minimum Bootstrap Voltage BST Pin Current Oscillator Switching Frequency Foldback Frequency Soft Start and Overload ...

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Pin Descriptions SO-8 Pin Name Pin Function Emitter of the internal NPN power transistor. Connect this pin to the inductor, the freewheeling diode and the  SW bootstrap capacitor. Power supply to the regulator also the collector of ...

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Block Diagram COMP COMP FREQUENCY FREQUENCY FOLDBACK FOLDBACK ROSC ROSC SS/EN SS/ REFERENCE REFERENCE ...

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Eff Typical Characteristics Efficiency =3. =2. =1. (5) V =12V IN 50 1MHz 0.5 1 1.5 2 Load ...

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Typical Characteristics (Cont.) SS270 REV 6-7 V Thresholds vs Temperature IN 3.0 2.9 Start 2.8 2.7 2.6 (14) UVLO 2.5 2.4 -50 - Temperature ( SS270 REV 6-7 V Quiescent Current 2.5 ...

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Applications Information Operation The SC4525A is a constant-frequency, peak current- mode, step-down switching regulator with an integrated 28V, 3.6A power NPN transistor. Programmable switching frequency makes the regulator design more flexible. With the peak current-mode control, the double reactive poles ...

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Applications Information (Cont.) As the load draws more current from the regulator, the current-limit comparator ILIM (Figure 2) will eventually limit the switch current on a cycle-by-cycle basis. The over-current signal OC goes high, setting the latch B soft-start capacitor ...

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Applications Information (Cont.) Minimum Off Time Limitation The PWM latch in Figure 2 is reset every cycle by the clock. The clock also turns off the power transistor to refresh the bootstrap capacitor. This minimum off time limits the attainable ...

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Applications Information (Cont.) diodes should have an average forward current rating at least 3A and a reverse blocking voltage of at least a few volts higher than the input voltage. For switching regulators operating at low duty cycles (i.e. low ...

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Applications Information (Cont.) CONTROLLER AND SCHOTTKY DIODE CONTROLLER AND SCHOTTKY DIODE REF REF + + Vc Vc PWM PWM EA EA MODULATOR MODULATOR Vramp Vramp COMP COMP ...

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⋅ π ⋅ π ...

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Applications Information (Cont.) PCB Layout Considerations In a step-down switching regulator, the input bypass capacitor, the main power switch and the freewheeling diode carry pulse current (Figure 9). For jitter-free operation, the size of the loop formed by these components ...

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Recommended Component Parameters in Typical Applications Table 5 lists the recommended inductance (L voltages. The inductance is determined by assuming that the ripple current is 35% of load current I parameters are calculated by assuming a 47mF low ESR ceramic ...

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Typical Application Schematics V IN Figure 10. 300kHz 24V to 1.5V/3A Step-down Converter V IN Figure 11. 1MHz 10V-26V to 3.3V/3A Step-down Converter D1 D3 24V 18V Zener 1N4148 C4 4.7mF IN BST SW SC4525A SS/EN FB COMP ROSC GND ...

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Typical Performance Characteristics (For A 12V to 5V/3A Step-down Converter with 1MHz Switching Frequency) SS270 REV 6-7 Load Characteristic 0.5 1 1.5 2 2.5 Load Current (A) Figure 12(a). Load Characteristic 5V ...

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... THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Semtech Corporation Power Mangement Products Division 200 Flynn Road, Camarillo, CA 9302 Phone: (805) 498-2 Fax: (805) 498-3804 ...