A novel techniques for step down converter implemented by high voltage operational amplifier

This paper introduces techniques which can be used to step down input voltage. It is different from traditional idea which use duty cycle concept. By using frequency domain concept low pass active filter can be used to step down input voltage. While high pass active filter can be used to step up output voltage. High precision supply voltage at 1mV step can be generated by the proposed techniques without the series resistor and switches more than 1000 pieces if the cut off frequency of the filter is accurate enough. If the input voltage is not as high as 15 volt, op-amp model LF353 can be used to implement step down converter.