Project Analog - February 2009 - (Page 13)

ThE mcP3421 BaTTEry fuEl gaugE DEmo BoarD The MCP3421 Battery Fuel Gauge Demo Board demonstrates how to measure the battery voltage and discharging current using the MCP3421. The MCU algorithm calculates the battery fuel being used. This demo board is shipped with a 1.5V AAA nonrechargeable battery. The demo board displays the following parameters: (a) Measured battery voltage (b) Measured battery discharging current (c) Battery Fuel Used (calculated) The MCP3421 Battery Fuel Gauge Demo Board also can charge a single-cell 4.2V Li-Ion battery. This feature, however, is disabled by firmware since the demo kit is shipped to customers with a nonrechargeable 1.5V AAA battery. Other Microchip products that are supported include the MCP73831, MCP1702, and the PIC18F4550. Click here for more information on the MCP3421DM-BFG microchiP resources AN947: Power Management in Portable Applications: Charging Lithium-Ion/LithiumPolymer Batteries http://ww1. microchip.com/downloads/en/ AppNotes/00947a.pdf Battery Power Applications Design Guide http://ww1. microchip.com/downloads/en/ DeviceDoc/39610C.pdf TC105 Product Page http:// www.microchip.com/ wwwproducts/Devices. aspx?dDocName=en010707 AN786: Considerations for Driving Power MOSFETs in High-Current, Switch Mode Regulators http://ww1.microchip.com/downloads/en/ AppNotes/00786a.pdf Contents Viewpoint Selecting the Right dc/dc Converter Selecting the Right Battery System Understanding the Buck Switchmode Power Converter Analog news figurE 1 simPlEsT form of a sWiTchmoDE PoWEr coNvErTEr swiTchmode Power converTer The simplest form of a switchmode power converter is illustrated in Figure 1. The ideal switch opens and closes at a frequency of 1/T, where T represents the switch cycle period. The ratio of the on-time, or conduction time of the switch, to the period is referred to as the duty cycle, D. The resulting load voltage, VO, is a chopped version of the input. The load voltage looks like a series of pulses having an amplitude equal to the source voltage, VS. The average, or DC, value of the load voltage is simply the source voltage multiplied by the duty cycle. In this simple configuration, the load voltage is always less than or equal to the source voltage with the same polarity. The DC load voltage does not come without a price. Substantial ripple is present not only in the load voltage, but in the input source current as well. Most applications can not take advantage of this type of conversion without employing some type of low pass filter to smooth the ripple. To view the full application note, click here. Microchip analog page Sample center microchipDIRECT Reference designs/ app notes Technical training 13 · PRojeCt ANAlog · VolUme 3 / NUmBeR 1 http://ww1.microchip.com/downloads/en/AppNotes/00947a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00947a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00947a.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/39610C.pdf http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010707 http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010707 http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010707 http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010707 http://www.microchip.com http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=79&redirects=analog http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=79&redirects=analog http://ww1.microchip.com/downloads/en/AppNotes/00786a.pdf http://sample.microchip.com/Default.aspx?testCookies=true http://ww1.microchip.com/downloads/en/AppNotes/00786a.pdf http://ww1.microchip.com/downloads/en/AppNotes/00793a.pdf http://www.microchipdirect.com/catalogselection.aspx?returnURL=default.aspx http://ww1.microchip.com/downloads/en/AppNotes/00786a.pdf http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1469&filter1=function&redirects=appnotes http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en532698 http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1469&filter1=function&redirects=appnotes http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1423 Table of Contents for the Digital Edition of Project Analog - February 2009Project Analog - February 2009ContentsViewpointAbout Project Analog SponsorSelecting the Right dc/dc Converter for Portable ApplicationsSelecting the Right Battery System for Portable ApplicationsUnderstanding the Buck Switchmode Power ConverterComparing A/D Power Management TechniquesThermal Management of dc/dc Power ModulesAnalog NewsContact MicrochipLinkedInTreelinkMicrochip Advanced Parts Selector (MAPS)Project Analog - February 2009Project Analog - February 2009 - Project Analog - February 2009 (Page Cover1)Project Analog - February 2009 - Contents (Page 2)Project Analog - February 2009 - Viewpoint (Page 3)Project Analog - February 2009 - About Project Analog Sponsor (Page 4)Project Analog - February 2009 - Selecting the Right dc/dc Converter for Portable Applications (Page 5)Project Analog - February 2009 - Selecting the Right dc/dc Converter for Portable Applications (Page 6)Project Analog - February 2009 - Selecting the Right dc/dc Converter for Portable Applications (Page 7)Project Analog - February 2009 - Selecting the Right dc/dc Converter for Portable Applications (Page 8)Project Analog - February 2009 - Selecting the Right Battery System for Portable Applications (Page 9)Project Analog - February 2009 - Selecting the Right Battery System for Portable Applications (Page 10)Project Analog - February 2009 - Selecting the Right Battery System for Portable Applications (Page 11)Project Analog - February 2009 - Understanding the Buck Switchmode Power Converter (Page 12)Project Analog - February 2009 - Understanding the Buck Switchmode Power Converter (Page 13)Project Analog - February 2009 - Comparing A/D Power Management Techniques (Page 14)Project Analog - February 2009 - Comparing A/D Power Management Techniques (Page 15)Project Analog - February 2009 - Comparing A/D Power Management Techniques (Page 16)Project Analog - February 2009 - Comparing A/D Power Management Techniques (Page 17)Project Analog - February 2009 - Thermal Management of dc/dc Power Modules (Page 18)Project Analog - February 2009 - Thermal Management of dc/dc Power Modules (Page 19)Project Analog - February 2009 - Thermal Management of dc/dc Power Modules (Page 20)Project Analog - February 2009 - Analog News (Page 21)Project Analog - February 2009 - Contact Microchip (Page 22)Project Analog - February 2009 - LinkedIn (Page 23)Project Analog - February 2009 - Treelink (Page 24)Project Analog - February 2009 - Microchip Advanced Parts Selector (MAPS) (Page 25)Project Analog - February 2009 - Microchip Advanced Parts Selector (MAPS) (Page Cover4)http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200902http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200810http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200808http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200804http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200803http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200802http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200801http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200712http://www.nxtbook.com/nxtbooks/hearst/projectanalog_200711http://www.nxtbookMEDIA.com

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