Programmable Voltage Regulator Design based on Digitally Controlled Potentiometer

Abstract

The traditional adjustable linear voltage regulator and switching regulator are both through adjusting the resistance value to change the output voltage. This method has the defaults of low accuracy and not convenience. Using the digital controlled potentiometer but the adjustable resistor, a programmable voltage regulator controlled by computer can be composed. The paper provided three design projects of programmable linear voltage regulator that composed by digitally controlled potentiometer. In the first design project the digitally controlled potentiometer is running in adjustable resistor mode. The second one is adjustable voltage divider mode. And the third design project is using the digital controlled potentiometer to realize the accurate adjust of the output voltage in a small range. Then the paper analyzed the voltage regulation range of the programmable voltage regulator and the stabilized voltage characteristic without load of the voltage regulator and the design note. It is often needed in the field of industry control that a kind of high efficiency, low output voltage digital controlled linear voltage regulator, which can be adjusted exactly in a small range. To meet the need, a kind of programmable accurate low dropout regulator is design by the digital controlled potentiometer and LDO (low dropout regulator). Finally a kind of programmable switching regulator is provided, which is composed by digital controlled potentiometer and adjustable buck mode switching regulator. The voltage regulator not only has the turn off function, which can cause the regulator into stand by mode with low power dissipation, but also the regulator has good protection circuit includes over current protection and overheat protection. The design projects provided are all of practical value.