Patent ID: 7522433

Claim:
A voltage rail generation apparatus for generating N intermediate voltage rails between a first voltage reference (VDD) and a second voltage reference (GND) at N intermediate voltage rail outputs, where N is a positive integer greater than 1, the apparatus comprising: (A) a flying capacitor (FC) having a first FC terminal and a second FC terminal; (B) a plurality of switch pairs including, (i) a first switch pair including, a first switch (S 1 ) coupling the first FC terminal to the first voltage reference, and a second switch (S 2 ) coupling the second FC terminal to a highest (R 1 ) of the intermediate voltage rail outputs, (ii) a last switch pair including, a first switch coupling the first FC terminal to a lowest of the intermediate voltage rail outputs, and a second switch coupling the second FC terminal to the second voltage reference, and (iii) N−1 intermediate switch pairs each including, a first switch coupling the first FC terminal to the second switch of a next higher switch pair, and a second switch coupling the second FC terminal to a next lower of the intermediate voltage rail outputs; (C) N storage capacitors each coupled between the second voltage reference and a respective one of the intermediate voltage rail outputs.