New-Technology-Blog.com

Ideal Diodes Reduce Power Waste In Battery Systems

A diode’s electricity conducting direction is called its forward direction and its blocking direction is called its reverse direction.  Solid state diodes made of silicon exhibit a drop in voltage when forward conducting.  Standard silicon diodes exhibit a forward voltage drop of 0.50 to 0.70 volts in the forward direction.  Schotkey silicon diodes exhibit a forward voltage drop of 0.25 to 0.30 volts in the forward direction.  Power loss in the diode is roughly equal to the forward current multiplied by the forward voltage drop.  Thus a battery which supplies 10 amps through a silicon diode with a forward voltage drop of 0.50 V will exhibit 5 watts of power lost to heat.

Ideal diode circuits permits today’s designer to replace silicon diodes with a low resistance N-Channel Field Effect Transistor (N-FET).  Implemented within a small integrated circuit package, the ideal diode circuit monitors the voltage drop across the source and drain of an N Channel FET.  The circuit turns the N-FET on and off as required to permit unidirectional current flow  -  just like a solid state diode, but with far less power loss.  Today’s modest N-Channel FETs have an on-time drain-source resistance of 0.005 ohms.  Such a device when used with a 10 Amp battery system would exhibit a power loss of ((10 * 10) * 0.005) = 0.5 W.

Using an ideal diode, power loss in high current battery systems may be reduced by a factor of ten or more when compared to standard silicon diode performance.  This energy savings will improve a user’s experience of perceived battery life.  Orchid Technologies Engineering and Consulting, Inc. has performed the design of numerous high energy battery systems using lithium, nickel-metal, nickel-cadmium, and lead acid technologies. With hundreds of successful project completions, Orchid is uniquely suited to engineer your concept into reality. Orchid will work with your idea, perform detailed design, construct prototype units, refine the prototype design and manufacture your electronic product. Fast. Accurately. On time and on budget. Contact Paul Nickelsberg, President and Senior Engineer with Orchid Technologies Engineering and Consulting at 978-461-2000 to discuss your new design projects. Visit our web site at www.orchid-tech.com to review our recent designs. Contact Paul Nickelsberg, President and CTO of Orchid at 978-461-2000 or email paul@orchid-tech.com for more information.

This entry was posted on Tuesday, September 22nd, 2009 at 7:47 pm and is filed under New Technology. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.