Patent ID: 7471071

Claim:
A boost regulator comprising: a first boost regulator having a voltage input terminal for supplying power to components in the first boost regulator, the first boost regulator for controlling switching of a first transistor to supply a boosted voltage at an output node, the first boost regulator requiring at least a first voltage level at the voltage input terminal to operate properly; an inductor coupled at one end to a power supply voltage and at a second end to a first node, the first node being coupled to a first terminal of the first transistor, wherein switching of the first transistor charges and discharges the inductor to control a voltage level at the output node; a pre-boost circuit comprising: an oscillator powered from the power supply voltage when the power supply voltage is less than the first voltage level required to operate the first boost regulator; a second transistor connected to the oscillator, the oscillator switching the second transistor when the power supply voltage is less than the first voltage level, the second transistor being coupled to the first node, wherein switching of the second transistor charges and discharges the inductor to ramp up the output voltage at the output node to be greater than the power supply voltage; a first connection for feeding a boosted voltage at the output node to the voltage input terminal of the first boost regulator, whereby the boosted voltage causes the first boost regulator to be operational after the voltage at the voltage input terminal is at least the first voltage level; and a detection circuit for disabling the pre-boost circuit after the first boost regulator has become operational and begins switching the first transistor.