Alan Elbanhawy: New Applications
http://www.maplesoft.com/applications/author.aspx?mid=62264
en-us2014 Maplesoft, A Division of Waterloo Maple Inc.Maplesoft Document SystemSat, 22 Nov 2014 10:30:04 GMTSat, 22 Nov 2014 10:30:04 GMTNew applications published by Alan Elbanhawyhttp://www.mapleprimes.com/images/mapleapps.gifAlan Elbanhawy: New Applications
http://www.maplesoft.com/applications/author.aspx?mid=62264
Control Loop Compensation for Buck Converter
http://www.maplesoft.com/applications/view.aspx?SID=139253&ref=Feed
<p>Switch mode power supplies have been supplying most of the DC voltages that modern electronics need for operation. It is not unusual that a single piece of electronic equipment to have more than 10 or even 15 to 20 different voltages all at different currents. Power supply design engineers must have a good understanding of the stability requirements and be able to design the best fitting compensation circuit for the application.</p><img src="/view.aspx?si=139253/afb6e746c0d6b75320beb456bfa4d086.gif" alt="Control Loop Compensation for Buck Converter" align="left"/><p>Switch mode power supplies have been supplying most of the DC voltages that modern electronics need for operation. It is not unusual that a single piece of electronic equipment to have more than 10 or even 15 to 20 different voltages all at different currents. Power supply design engineers must have a good understanding of the stability requirements and be able to design the best fitting compensation circuit for the application.</p>139253Tue, 06 Nov 2012 05:00:00 ZAlan ElbanhawyAlan ElbanhawyEffect of Source Inductance on MOSFET Rise and Fall Times
http://www.maplesoft.com/applications/view.aspx?SID=5730&ref=Feed
The need for advanced MOSFETs for DC-DC converters applications is growing as the push for applications miniaturization going hand in hand with increased power consumption. These advanced new designs should theoretically translate into doubling the average switching frequency of the commercially available MOSFETs while maintaining the same high or even higher efficiency.<img src="/view.aspx?si=5730/Source_inductance_effects_2.gif" alt="Effect of Source Inductance on MOSFET Rise and Fall Times" align="left"/>The need for advanced MOSFETs for DC-DC converters applications is growing as the push for applications miniaturization going hand in hand with increased power consumption. These advanced new designs should theoretically translate into doubling the average switching frequency of the commercially available MOSFETs while maintaining the same high or even higher efficiency.5730Wed, 26 Mar 2008 00:00:00 ZAlan ElbanhawyAlan ElbanhawyCross Conduction in Modern Power MOSFETs
http://www.maplesoft.com/applications/view.aspx?SID=5698&ref=Feed
The synchronous buck converter is the DC-DC converter of choice in PC and notebook computers and has been so for many years. This topology provides ease of control and high power conversion efficiencies at a relatively low cost and within a small footprint. One of the keys to success in designing a synchronous buck converter is limiting the shoot-through or cross-conduction current. This phenomenon can cause excessive losses which leads to poor performance and results in low power conversion efficiency. Mathematical formulae will be derived that allow MOSFET and power supply designers to test the suitability of a specific device for its use as a synchronous rectifier in this converter.<img src="/view.aspx?si=5698/CrossConductionModernPowerM.gif" alt="Cross Conduction in Modern Power MOSFETs" align="left"/>The synchronous buck converter is the DC-DC converter of choice in PC and notebook computers and has been so for many years. This topology provides ease of control and high power conversion efficiencies at a relatively low cost and within a small footprint. One of the keys to success in designing a synchronous buck converter is limiting the shoot-through or cross-conduction current. This phenomenon can cause excessive losses which leads to poor performance and results in low power conversion efficiency. Mathematical formulae will be derived that allow MOSFET and power supply designers to test the suitability of a specific device for its use as a synchronous rectifier in this converter.5698Mon, 10 Mar 2008 00:00:00 ZAlan ElbanhawyAlan ElbanhawyConduction Loss
http://www.maplesoft.com/applications/view.aspx?SID=5697&ref=Feed
As the PC makers push for DC-DC converters delivering >150 Amps at output voltages =1V within the next few years, the semiconductor manufacturers are pushing to optimize their MOSFET by improving both the silicon and the packages to provide switching devices suitable for these challenges. In this paper we will address the parasitic resistance attributed to the package alone and in isolation from the silicon on-resistance. We will show that in most of the traditional packages this resistance has a very strong frequency dependent component.
This means that at a switching frequency of about a few Megahertz, this parasitic resistance will constitute a large percentage of the total device on-resistance and hence influences the losses greatly. Based on this observation, we will concentrate on the topology of choice, the synchronous buck converter, and we will derive conduction loss equations that are frequency dependent and calculate actual losses and examine several effects that follow.<img src="/view.aspx?si=5697/thumb.jpg" alt="Conduction Loss" align="left"/>As the PC makers push for DC-DC converters delivering >150 Amps at output voltages =1V within the next few years, the semiconductor manufacturers are pushing to optimize their MOSFET by improving both the silicon and the packages to provide switching devices suitable for these challenges. In this paper we will address the parasitic resistance attributed to the package alone and in isolation from the silicon on-resistance. We will show that in most of the traditional packages this resistance has a very strong frequency dependent component.
This means that at a switching frequency of about a few Megahertz, this parasitic resistance will constitute a large percentage of the total device on-resistance and hence influences the losses greatly. Based on this observation, we will concentrate on the topology of choice, the synchronous buck converter, and we will derive conduction loss equations that are frequency dependent and calculate actual losses and examine several effects that follow.5697Mon, 10 Mar 2008 00:00:00 ZAlan ElbanhawyAlan Elbanhawy