Patent ID: 7436385

Claim:
An analog buffer for buffering an input voltage to an output line, comprising: a constant current source to supply a constant current to the output line; and a comparator to compare a voltage charged on the output line with the input voltage to turn-off the constant current source if it is determined that the voltage charged on the output line corresponding to the input voltage is buffered to the output line, wherein the comparator includes: an inverter connected between an input line of the input voltage and the constant current source; a capacitor connected in series between the input line and the inverter; a first switch to switch the input voltage on the input line; a second switch connected between an input terminal and an output terminal of the inverter; and a third switch connected between the input line and the output line, wherein the constant current source includes: a fourth switch to provide a conductive path between a first supply voltage line and the output line; a fifth switch to control a conductive path between the fourth switch and the output line; and a sixth switch connected in parallel to the output line, wherein the first, second and sixth switches operate contrary to the third and fifth switches.