Patent ID: 8729959

Claim:
A voltage generating apparatus, comprising: a reference voltage generator for generating a reference voltage, the reference voltage generator deciding to generate the reference voltage or not according to a control signal; and an output voltage generator coupled to the reference voltage generator, the output voltage generator comprising: a comparator comparing the reference voltage and an output voltage to generate a calibrating signal; a variable resistor coupled to the comparator, a resistance of the variable resistor being decided by the calibrating signal; a current source coupled to the variable resistor, the current source providing an output current to flow through the variable resistor for generating the output voltage; a binary search logic circuit coupled between the comparator and the variable resistor, wherein the binary search logic circuit generates the calibrating signal according to an output of the comparator by a binary search algorithm; and a diode, wherein a cathode of the diode is coupled to a reference ground, and an anode of the diode is coupled to the variable resistor, wherein the reference voltage is generated during an initial timing period, and the generator is turned off after the initial timing period, the initial timing period is determined according to the control signal.