Abstract: This circuit exploits all the power available from a USB port by dynamically adjusting the amount of current delivered to the load, thereby siphoning a relatively constant (and maximum) current from the USB port. Included are a current-sense amplifier (MAX4173), voltage reference (MAX6129), and precision op amp (MAX4238). Maxim > App Notes > Amplifier and Comparator Circuits Interface Circuits Voltage References Keywords: USB ports, USB-port power, current-sense amplifiers, voltage references, op amps, n-channel MOSFETs Jan 05, 2011 APPLICATION NOTE 4563 Dynamic Siphon Steals Current from USB Port Abstract:This circuit exploits all the power available from a USB port by dynamically adjusting the amount of current delivered to the load, thereby siphoning a relatively constant (and maximum) current from the USB port. Included are a current-sense amplifier (MAX4173), voltage reference (MAX6129), and precision op amp (MAX4238). A similar version of this article appeared in the Decmeber 15, 2006 issue of EDN magazine. USB ports can be a handy source of 5V power. Not only can a USB port power a ……