Project Analog - April 2008 - (Page 13) Driving power MOSFETs in Switch Mode power Supplies Contributed by Microchip Technology www.microchip.com why use dedicated MosFet drivers? Traditional Switch Mode Power Supply (SMPS) controllers have on-board drivers suitable for some applications. Typically, these drivers have peak output currents of 1A or less, limiting their scope of applications. In addition, the heat generated in these drivers causes the on-chip reference voltage to change. The need for “smarter” power supplies are forcing SMPS controllers to grow in sophistication. Many newer SMPS controllers are fabricated in smaller geometry CMOS process technologies, precluding the use of high voltage (i.e. voltages 13 · prOjECT ANAlOg · Apr 08 Contents Viewpoint Calculating Power Dissipation Accelerating Amplifier Design Driving Power MOSFETs Analog news greater than 12V). In such cases, the external MOSFET driver also acts as a level shifter, translating TTLcompatible levels to MOSFET drive voltages. A device like the TC4427A for example, furnishes a rail-to-rail output swing (from the maximum VDD of 18V) from an input swing of VL = 0.8V and VIH = 2.4V. Latch-up immunity is another consideration. Latch-up immunity is particularly important in that the driven MOSFETs typically drive inductive circuits that generate significant “kickback” currents. MOSFET drivers like the TC4427A can withstand as much as 0.5A of reverse output current without damage or upset. Microchip analog page MOSFET driver overview Sample center microchipDIRECT Reference designs/ app notes Technical training http://www.microchip.com http://www.microchip.com http://www.microchip.com/analog http://www.microchip.com/analog http://www.microchip.com/mosfetdriver http://www.microchip.com/mosfetdriver http://sample.microchip.com/Default.aspx?testCookies=true http://www.microchipdirect.com/catalogselection.aspx?returnURL=default.aspx 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=1469&filter1=function&redirects=appnotes http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1423
Table of Contents Feed for the Digital Edition of Project Analog - April 2008 Project Analog - April 2008 Contents Viewpoint About Project Analog Sponsor Calculating Power Dissipation in a MOSFET Driver Accelerating Design of >50-W Class D Amplifiers Driving Power MOSFETs in Switch Mode Power Supplies Synergistic MOSFET Solutions Trends in MOSFET Gate Drivers Analog News—Analog news from multiple sources Enter to win an iPhone Contact Project Analog Sponsor Treelink Microchip Advanced Parts Selector (MAPS) Project Analog - April 2008 Project Analog - April 2008 - Project Analog - April 2008 (Page 1) Project Analog - April 2008 - Contents (Page 2) Project Analog - April 2008 - Viewpoint (Page 3) Project Analog - April 2008 - About Project Analog Sponsor (Page 4) Project Analog - April 2008 - Calculating Power Dissipation in a MOSFET Driver (Page 5) Project Analog - April 2008 - Calculating Power Dissipation in a MOSFET Driver (Page 6) Project Analog - April 2008 - Calculating Power Dissipation in a MOSFET Driver (Page 7) Project Analog - April 2008 - Calculating Power Dissipation in a MOSFET Driver (Page 8) Project Analog - April 2008 - Calculating Power Dissipation in a MOSFET Driver (Page 9) Project Analog - April 2008 - Accelerating Design of >50-W Class D Amplifiers (Page 10) Project Analog - April 2008 - Accelerating Design of >50-W Class D Amplifiers (Page 11) Project Analog - April 2008 - Accelerating Design of >50-W Class D Amplifiers (Page 12) Project Analog - April 2008 - Driving Power MOSFETs in Switch Mode Power Supplies (Page 13) Project Analog - April 2008 - Driving Power MOSFETs in Switch Mode Power Supplies (Page 14) Project Analog - April 2008 - Driving Power MOSFETs in Switch Mode Power Supplies (Page 15) Project Analog - April 2008 - Synergistic MOSFET Solutions (Page 16) Project Analog - April 2008 - Synergistic MOSFET Solutions (Page 17) Project Analog - April 2008 - Synergistic MOSFET Solutions (Page 18) Project Analog - April 2008 - Trends in MOSFET Gate Drivers (Page 19) Project Analog - April 2008 - Trends in MOSFET Gate Drivers (Page 20) Project Analog - April 2008 - Trends in MOSFET Gate Drivers (Page 21) Project Analog - April 2008 - Analog News—Analog news from multiple sources (Page 22) Project Analog - April 2008 - Contact Project Analog Sponsor (Page 23) Project Analog - April 2008 - Treelink (Page 24) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 25) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 26) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 27) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 28) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 29) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 30) Project Analog - April 2008 - Microchip Advanced Parts Selector (MAPS) (Page 31)
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.