IR3721MTRPBF International Rectifier, IR3721MTRPBF Datasheet
IR3721MTRPBF
Specifications of IR3721MTRPBF
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IR3721MTRPBF Summary of contents
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... Single buck or multiphase converters • Inductor DCR or resistive shunt sensing Simple add-on to existing converters 10 pin 3x3 DFN lead free package RoHS compliant TYPICAL APPLICATION CIRCUIT ORDERING INFORMATION Device IR3721MTRPBF * IR3721MPBF * Samples only Page Power Monitor IC with DESCRIPTION The IR3721 is a versatile power or current monitor IC for low-voltage DC-DC converters ...
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ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings (Referenced to GND) VDD:.................................................................3.9V All other Analog and Digital pins ......................3.9V Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only and functional operation ...
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BLOCK DIAGRAM VO VCS I REF PIN DESCRIPTION NAME NUMBER I/O LEVEL VCS 1 Analog VO 2 Analog VRT 3 Analog GND 4 VDD 5 3.3V GND 6 GND Analog VK 9 1.8V VDD ...
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IC PIN FUNCTIONS VDD PINS These pins provide operational bias current to circuits internal to the IR3721. Bypass them with a high quality ceramic capacitor to the GND pins. GND PINS These pins return operational bias current to system ground. ...
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FUNCTIONAL DESCRIPTION Please refer to the Functional Description Diagram below. Power flow from the buck converter inductor is the product of output voltage times the current I flowing through the inductor. Power is measured with the aid of International Rectifier’s ...
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THERMAL COMPENSATION FOR INDUCTOR DCR CURRENT SENSING The positive temperature coefficient of the inductor DCR can be compensated if R varies inversely T proportional to the DCR. DCR of a copper coil function of temperature, is approximated by ...
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TYPICAL 2-PHASE DCR SENSING APPLICATION The IR3721 is capable of monitoring power in a multiphase converter. A Two Phase DCR Sensing Circuit is shown below. The voltage output of any phase is equal to that of any and every other ...
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RESISTOR SENSING APPLICATION The Resistor Sensing Circuit shown below is an example of resistive current sensing. Because the voltage on the shunt resistor is directly proportional to the current I through the inductor not need to match the ...
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COMPONENT SELECTION GUIDELINES Use a 0.1 μF, 6.3V, X7R ceramic bypass capacitor from VDD to GND and from VK to GND. Filter the DI output with an RC filter to give a stable analog representation of the current or power. ...
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L > ⋅ ) DCR 25 R Choose a standard capacitor value larger than indicated by the right hand side of the inequality above. Calculate the equivalent resistance (DCR(25) ...
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LAYOUT GUIDELINES Refer to figures 7 through 11 for guidance laying out the IR3721. These guidelines also apply to resistive current sensing. The following guidelines will minimize sources of noise and error, which is required because millivolt level signals correspond ...
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Figure 8 Layer 1 Figure 9 Layer 2 Page Figure 10 Layer 3 Figure 11 Layer 4 www.irf.com IR3721 DATA SHEET 09/15/08 ...
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PCB PAD AND COMPONENT PLACEMENT Figure 12 below shows suggested pad and component placement. Figure 12 Pad placement Page www.irf.com IR3721 DATA SHEET 09/15/08 ...
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SOLDER RESIST Figure 13 below shows suggested solder resist placement. Figure 13 Solder resist Page www.irf.com IR3721 DATA SHEET 09/15/08 ...
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STENCIL DESIGN Figure 14 below shows a suggested stencil design. Figure 14 Stencil design Page www.irf.com IR3721 DATA SHEET 09/15/08 ...
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PACKAGE INFORMATION 10L DFN LEAD FREE IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 Page Data and specifications subject to change without notice. This product has been ...